Update submodule

Add ability to read alarm times
Add alarms to example
2020-05-17 20:11:51 +02:00 · 2020-05-17 20:07:13 +02:00 · 2020-05-17 19:56:11 +02:00 · 2020-05-17 15:40:29 +02:00 · 2020-05-17 15:40:15 +02:00 · 2020-05-16 19:52:49 +02:00
31 changed files with 542 additions and 1116 deletions
@@ -1,15 +1,13 @@
 ---
 BasedOnStyle: LLVM
-Standard: Latest
 ColumnLimit: 120
 IndentWidth: 4
 TabWidth: 4
 UseTab: ForIndentation
 AlignEscapedNewlines: DontAlign
 AllowShortFunctionsOnASingleLine: Empty
-BreakTemplateDeclarations: Yes
+AlwaysBreakTemplateDeclarations: true
 BreakBeforeBraces: Custom
 BraceWrapping:
  AfterFunction: true
-InsertBraces: true
 ...
@@ -1,32 +0,0 @@
-# Editor accommodations for the second frontend. No compilation database is
-# named here: this driver is made to be vendored, and this file travels with
-# it - a consumer's own database then covers these headers, at the consumer's
-# chip. The checkout that is opened as a folder names its build tree in
-# .vscode/settings.json instead.
-CompileFlags:
-  Add:
-    # clang has no 24-bit integer and GCC's are keywords, not macros, so the
-    # editor needs a stand-in for avr::uint24_t. The next width up is the only
-    # one available - clang rejects _BitInt(24) on this target.
-    - -D__uint24=unsigned long
-    - -D__int24=long
-    # clangd forwards the driver's system includes but not its own header
-    # directory, so <stdint.h> resolves to avr-libc's, which still gates the
-    # limit and constant macros on the C++98 opt-in.
-    - -D__STDC_LIMIT_MACROS
-    - -D__STDC_CONSTANT_MACROS
-    # isr::emit spells a vector number into [[gnu::signal(N)]], which clang
-    # rejects rather than ignores - enough of them in one TU to reach the
-    # default limit of 19 inside the headers and truncate the parse.
-    - -ferror-limit=0
-  Remove:
-    # The build promotes warnings for the compiler that has to be right about
-    # them; in the editor the flag paints a second frontend's opinions in the
-    # colour reserved for things that do not compile.
-    - -Werror
-Diagnostics:
-  Suppress:
-    # clang's AVR `signal` attribute takes no arguments and it knows none of
-    # progmem, naked or OS_main. A misspelling is what the build is for.
-    - attribute_wrong_number_arguments
-    - unknown-attributes
@@ -1,8 +1,9 @@
-# Line endings are the repository's, not the editing tool's (libavr guidance
-# rule 50): a file rewritten by a Windows tool must not come back with every
-# line changed.
-* text=auto eol=lf
-
-# Atmel Studio writes these and expects them back.
+*.h         eol=lf
+*.hpp       eol=lf
+*.c         eol=lf
+*.cpp       eol=lf
+.git*       eol=lf
+*.vcxproj*  eol=crlf
 *.cppproj   eol=crlf
+*.sln       eol=crlf
 *.atsln     eol=crlf
@@ -1,10 +1,11 @@
-build/
-local/
-.cache/
-
-# Atmel Studio: generated per machine, its build outputs, and per-user state
-ide/*/*.componentinfo.xml
-ide/*/Debug/
-ide/*/Release/
-ide/.vs/
-ide/*.log
+.vs
+Release
+Debug
+*.componentinfo.xml
+*.elf
+*.o
+*.hex
+*.srec
+*.eeprom
+*.lss
+*.map
@@ -1,3 +1,18 @@
-[submodule "libavr"]
-	path = libavr
-	url = ../libavr.git
+[submodule "ds3231/ds3231"]
+	path = ds3231/ds3231
+	url = git@git.blackmark.me:avr/ds3231.git
+[submodule "ds3231/uart"]
+	path = ds3231/uart
+	url = git@git.blackmark.me:avr/uart.git
+[submodule "ds3231/io"]
+	path = ds3231/io
+	url = git@git.blackmark.me:avr/io.git
+[submodule "ds3231/flash"]
+	path = ds3231/flash
+	url = git@git.blackmark.me:avr/flash.git
+[submodule "ds3231/i2c"]
+	path = ds3231/i2c
+	url = git@git.blackmark.me:avr/i2c.git
+[submodule "ds3231/util"]
+	path = ds3231/util
+	url = git@git.blackmark.me:avr/util.git
@@ -1,6 +0,0 @@
-{
-	"recommendations": [
-		"llvm-vs-code-extensions.vscode-clangd",
-		"ms-vscode.cmake-tools"
-	]
-}
@@ -1,39 +0,0 @@
-{
-	// clangd is the language server; the cpptools engine would parse every file
-	// a second time and disagree, since nothing tells it about a cross
-	// compiler.
-	"C_Cpp.intelliSenseEngine": "disabled",
-
-	// --query-driver lets clangd ask the cross compiler for its own system
-	// includes and target. The database is named here rather than in .clangd
-	// because that file travels with the driver into a consumer's submodule,
-	// where a build tree of this repo's own need not exist. It sits one level
-	// above the trees, and CMake Tools copies the selected preset's into it on
-	// every configure: the database carries `-mmcu`, so a fixed tree would
-	// check the driver against one chip.
-	"clangd.arguments": [
-		"--compile-commands-dir=${workspaceFolder}/build",
-		"--query-driver=**avr-g++*",
-		"--header-insertion=never"
-	],
-	"cmake.copyCompileCommands": "${workspaceFolder}/build/compile_commands.json",
-
-	// The presets are the build interface, and the toolchain file inside the
-	// libavr submodule is the one place the compiler is chosen. No prefix is
-	// named here: the gitignored local/machine.cmake at this repository's root
-	// is where a checkout says where its toolchain is (libavr guidance rule 50).
-	"cmake.useCMakePresets": "always",
-	"cmake.configureOnOpen": true,
-	"cmake.options.statusBarVisibility": "compact",
-
-	"files.watcherExclude": {
-		"**/build/**": true,
-		"**/local/**": true,
-		"**/libavr/**": true
-	},
-
-	"files.associations": {
-		".clangd": "yaml",
-		".clang-format": "yaml"
-	}
-}
@@ -1,29 +0,0 @@
-cmake_minimum_required(VERSION 3.28)
-
-project(ds3231 LANGUAGES CXX)
-
-# libavr rides as the pinned submodule; LIBAVR_ROOT (cache or environment)
-# overrides it for tandem development against a working tree. The toolchain
-# file comes from the submodule via CMakePresets.json either way.
-if(NOT LIBAVR_ROOT AND DEFINED ENV{LIBAVR_ROOT})
-	set(LIBAVR_ROOT $ENV{LIBAVR_ROOT})
-endif()
-if(NOT LIBAVR_ROOT)
-	set(LIBAVR_ROOT ${CMAKE_CURRENT_SOURCE_DIR}/libavr)
-endif()
-if(NOT EXISTS ${LIBAVR_ROOT}/CMakeLists.txt)
-	message(FATAL_ERROR "libavr not found at ${LIBAVR_ROOT} - run: git submodule update --init libavr")
-endif()
-add_subdirectory(${LIBAVR_ROOT} libavr-build)
-
-add_library(ds3231 INTERFACE)
-target_include_directories(ds3231 INTERFACE ${CMAKE_CURRENT_SOURCE_DIR}/include)
-target_link_libraries(ds3231 INTERFACE libavr)
-
-include(${LIBAVR_ROOT}/cmake/checks.cmake)
-
-if(PROJECT_IS_TOP_LEVEL)
-	add_subdirectory(example)
-	enable_testing()
-	add_subdirectory(test)
-endif()
@@ -1,43 +0,0 @@
-{
-	"version": 8,
-	"configurePresets": [
-		{
-			"name": "base",
-			"hidden": true,
-			"generator": "Ninja",
-			"binaryDir": "${sourceDir}/build/${presetName}",
-			"toolchainFile": "${sourceDir}/libavr/cmake/avr-toolchain.cmake",
-			"cacheVariables": {
-				"CMAKE_BUILD_TYPE": "Release",
-				"CMAKE_EXPORT_COMPILE_COMMANDS": "ON",
-				"CMAKE_COLOR_DIAGNOSTICS": "ON"
-			}
-		},
-		{
-			"name": "attiny85-generated",
-			"inherits": "base",
-			"cacheVariables": { "LIBAVR_MCU": "attiny85", "LIBAVR_REFLECT": "OFF" }
-		},
-		{
-			"name": "attiny85-reflect",
-			"inherits": "base",
-			"cacheVariables": { "LIBAVR_MCU": "attiny85", "LIBAVR_REFLECT": "ON" }
-		},
-		{
-			"name": "atmega328p-generated",
-			"inherits": "base",
-			"cacheVariables": { "LIBAVR_MCU": "atmega328p", "LIBAVR_REFLECT": "OFF" }
-		},
-		{
-			"name": "atmega328p-reflect",
-			"inherits": "base",
-			"cacheVariables": { "LIBAVR_MCU": "atmega328p", "LIBAVR_REFLECT": "ON" }
-		}
-	],
-	"buildPresets": [
-		{ "name": "attiny85-generated", "configurePreset": "attiny85-generated" },
-		{ "name": "attiny85-reflect", "configurePreset": "attiny85-reflect" },
-		{ "name": "atmega328p-generated", "configurePreset": "atmega328p-generated" },
-		{ "name": "atmega328p-reflect", "configurePreset": "atmega328p-reflect" }
-	]
-}
@@ -1,21 +0,0 @@
-MIT License
-
-Copyright (c) 2020 BlackMark
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is furnished
-to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice (including the next
-paragraph) shall be included in all copies or substantial portions of the
-Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
-FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS
-OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
-WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
-OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
@@ -1,97 +0,0 @@
-# ds3231
-
-Maxim DS3231 RTC driver on [libavr](https://git.blackmark.me/avr/libavr):
-clock and alarm read/write, alarm interrupts, oscillator-stop detection,
-die temperature. One source runs on every libavr chip — TWI hardware on
-the mega328P, open-drain software I2C on the tinies. All bus errors
-surface as `std::expected`.
-
-```cpp
-using bus = dev::i2c<{.frequency = 100_kHz}>;
-using rtc = ds3231::device<bus>;
-
-auto now = rtc::read_clock();       // result<date_time>
-auto armed = rtc::set_alarm1({}, ds3231::alarm1_rate::once_per_second);
-```
-
-`example/main.cpp` is a complete program. libavr rides as the `libavr/` submodule,
-pinned to the commit this driver builds against; `LIBAVR_ROOT` (cache or
-environment) overrides it for development against a working tree:
-
-```sh
-git submodule update --init libavr
-cmake --preset attiny85-generated
-cmake --build --preset attiny85-generated
-```
-
-Presets cover attiny85/atmega328p in both libavr modes (generated and
-reflect); `ctest` runs the consteval battery over the BCD, the hours
-register's two formats, the weekday, the alarm registers each rate writes and
-the control and status write-backs, and holds the example to its stated size —
-**1462 B** on the mega328P and **1256 B** on the tiny85, byte-identical across
-the two modes. The legacy
-yazoalfa-based driver lives on the `master` branch.
-
-The weekday register is derived from the date by default. A program that
-assigns its own meaning to the device's 1..7 takes ownership of it, and no
-write here touches it:
-
-```cpp
-using rtc = ds3231::device<bus, ds3231::weekday_source::external>;
-```
-
-An alarm arms its INT/SQW output unless told otherwise, and can be muted and
-re-wired without re-arming:
-
-```cpp
-auto quiet = rtc::set_alarm2(at, ds3231::alarm2_rate::minutes_match,
-                             ds3231::alarm_interrupt::off);
-auto again = rtc::listen_alarm2();
-```
-
-## Atmel Studio
-
-`master` carries a Studio solution, so this branch does too: `ide/ds3231.atsln`
-builds `example/main.cpp` for both parts the presets cover, each to a
-**byte-identical `.text`** against the CMake build (`check-flags.py` below is
-what holds the flag sets equal, so the sizes are the presets' own), with the
-flags mirrored by hand. CMake remains the build system.
-
-`avrdevice` is a project-level property in Studio, so a part means a project, not
-a configuration: `ide/atmega328p/` and `ide/attiny85/`. They need separate
-directories rather than separate names — Studio builds into `<project
-dir>/<Configuration>` whatever `OutputDirectory` says, so two projects sharing
-one directory would also share one `example/main.o`, and building one after the
-other without a rebuild would link the other part's object.
-
-Studio finds libavr in the **submodule** at
-`$(MSBuildProjectDirectory)\..\..\libavr\include` — correct by construction,
-and anchored to the project because a plain relative path is resolved against
-the generated makefile's directory (the configuration's output directory), not
-the project's. There is no `LIBAVR_ROOT` escape hatch: a variable exported in a
-shell is invisible to Studio launched from the Start menu — which is what the
-submodule answers. It also needs a GCC 16.1 toolchain registered as flavour
-`avr-g++-16.1.0`, nothing older reaching `-std=c++26`.
-
-One generated file is required before the project will load, and one command
-checks the flags have not drifted (both from libavr's `tools/atmelstudio/`):
-
-```sh
-for mcu in atmega328p attiny85; do
-    case $mcu in atmega328p) device=ATmega328P;; attiny85) device=ATtiny85;; esac
-    python libavr/tools/atmelstudio/componentinfo.py \
-        "ide/$mcu/ds3231-$mcu.componentinfo.xml" --device "$device"
-    python libavr/tools/atmelstudio/check-flags.py --solution ide/ds3231.atsln \
-        --project "ds3231-$mcu" \
-        --compile-commands "build/$mcu-generated/compile_commands.json" \
-        --log "build/as-$mcu.log"
-done
-```
-
-One reference describes one part, hence `--project`. Release is what the gate
-compares, the presets defining no debug build; Debug carries the `-Og
-gdwarf-4` pair libavr's own debug preset uses.
-
-Differences from legacy: weekday-rate alarms set the DY bit (the legacy
-driver always cleared it), each register block is read or written in one
-coherent bus transaction, and errors are reported instead of ignored.
@@ -0,0 +1,22 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Atmel Studio Solution File, Format Version 11.00
+VisualStudioVersion = 14.0.25420.1
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{E66E83B9-2572-4076-B26E-6BE79FF3018A}") = "ds3231", "ds3231\ds3231.cppproj", "{DCE6C7E3-EE26-4D79-826B-08594B9AD897}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|AVR = Debug|AVR
+		Release|AVR = Release|AVR
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{DCE6C7E3-EE26-4D79-826B-08594B9AD897}.Debug|AVR.ActiveCfg = Debug|AVR
+		{DCE6C7E3-EE26-4D79-826B-08594B9AD897}.Debug|AVR.Build.0 = Debug|AVR
+		{DCE6C7E3-EE26-4D79-826B-08594B9AD897}.Release|AVR.ActiveCfg = Release|AVR
+		{DCE6C7E3-EE26-4D79-826B-08594B9AD897}.Release|AVR.Build.0 = Release|AVR
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+EndGlobal
@@ -0,0 +1,4 @@
+#pragma once
+
+#define F_CPU 16'000'000
+#include <util/delay.h>
@@ -0,0 +1,285 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="14.0">
+  <PropertyGroup>
+    <SchemaVersion>2.0</SchemaVersion>
+    <ProjectVersion>7.0</ProjectVersion>
+    <ToolchainName>com.Atmel.AVRGCC8.CPP</ToolchainName>
+    <ProjectGuid>dce6c7e3-ee26-4d79-826b-08594b9ad897</ProjectGuid>
+    <avrdevice>ATmega328P</avrdevice>
+    <avrdeviceseries>none</avrdeviceseries>
+    <OutputType>Executable</OutputType>
+    <Language>CPP</Language>
+    <OutputFileName>$(MSBuildProjectName)</OutputFileName>
+    <OutputFileExtension>.elf</OutputFileExtension>
+    <OutputDirectory>$(MSBuildProjectDirectory)\$(Configuration)</OutputDirectory>
+    <AssemblyName>DailySafe</AssemblyName>
+    <Name>DailySafe</Name>
+    <RootNamespace>DailySafe</RootNamespace>
+    <ToolchainFlavour>avr-g++-9.1.0</ToolchainFlavour>
+    <KeepTimersRunning>true</KeepTimersRunning>
+    <OverrideVtor>false</OverrideVtor>
+    <CacheFlash>true</CacheFlash>
+    <ProgFlashFromRam>true</ProgFlashFromRam>
+    <RamSnippetAddress>0x20000000</RamSnippetAddress>
+    <UncachedRange />
+    <preserveEEPROM>true</preserveEEPROM>
+    <OverrideVtorValue>exception_table</OverrideVtorValue>
+    <BootSegment>2</BootSegment>
+    <ResetRule>0</ResetRule>
+    <eraseonlaunchrule>0</eraseonlaunchrule>
+    <EraseKey />
+    <avrtool>com.atmel.avrdbg.tool.atmelice</avrtool>
+    <avrtoolserialnumber>J41800099437</avrtoolserialnumber>
+    <avrdeviceexpectedsignature>0x1E950F</avrdeviceexpectedsignature>
+    <com_atmel_avrdbg_tool_stk500>
+      <ToolOptions>
+        <InterfaceProperties>
+          <IspClock>125000</IspClock>
+        </InterfaceProperties>
+        <InterfaceName>ISP</InterfaceName>
+      </ToolOptions>
+      <ToolType>com.atmel.avrdbg.tool.stk500</ToolType>
+      <ToolNumber>
+      </ToolNumber>
+      <ToolName>STK500</ToolName>
+    </com_atmel_avrdbg_tool_stk500>
+    <avrtoolinterface>ISP</avrtoolinterface>
+    <avrtoolinterfaceclock>125000</avrtoolinterfaceclock>
+    <AsfFrameworkConfig>
+      <framework-data xmlns="">
+        <options />
+        <configurations />
+        <files />
+        <documentation help="" />
+        <offline-documentation help="" />
+        <dependencies>
+          <content-extension eid="atmel.asf" uuidref="Atmel.ASF" version="3.47.0" />
+        </dependencies>
+      </framework-data>
+    </AsfFrameworkConfig>
+    <com_atmel_avrdbg_tool_atmelice>
+      <ToolOptions>
+        <InterfaceProperties>
+          <IspClock>125000</IspClock>
+        </InterfaceProperties>
+        <InterfaceName>ISP</InterfaceName>
+      </ToolOptions>
+      <ToolType>com.atmel.avrdbg.tool.atmelice</ToolType>
+      <ToolNumber>J41800099437</ToolNumber>
+      <ToolName>Atmel-ICE</ToolName>
+    </com_atmel_avrdbg_tool_atmelice>
+    <custom>
+      <ToolOptions>
+        <InterfaceProperties>
+          <IspClock>125000</IspClock>
+        </InterfaceProperties>
+        <InterfaceName>
+        </InterfaceName>
+      </ToolOptions>
+      <ToolType>custom</ToolType>
+      <ToolNumber>
+      </ToolNumber>
+      <ToolName>Custom Programming Tool</ToolName>
+    </custom>
+    <AAFDebugger>
+      <AAFDebugFiles>
+        <DebugFile>
+          <path>\Debug\ds3231.lss</path>
+          <AAFSetting>
+            <Label>Lss Files</Label>
+            <Extention>.lss</Extention>
+            <Regex>^\s*(?&lt;address&gt;[a-f0-9]*):\s*.*$</Regex>
+            <DebugEnabled>true</DebugEnabled>
+            <RegexGroups>address</RegexGroups>
+            <DebuggerExpression>$pc</DebuggerExpression>
+          </AAFSetting>
+        </DebugFile>
+      </AAFDebugFiles>
+    </AAFDebugger>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)' == 'Release' ">
+    <ToolchainSettings>
+      <AvrGccCpp>
+        <avrgcc.common.Device>-mmcu=atmega328p</avrgcc.common.Device>
+        <avrgcc.common.outputfiles.hex>True</avrgcc.common.outputfiles.hex>
+        <avrgcc.common.outputfiles.lss>True</avrgcc.common.outputfiles.lss>
+        <avrgcc.common.outputfiles.eep>True</avrgcc.common.outputfiles.eep>
+        <avrgcc.common.outputfiles.srec>True</avrgcc.common.outputfiles.srec>
+        <avrgcc.common.outputfiles.usersignatures>False</avrgcc.common.outputfiles.usersignatures>
+        <avrgcc.compiler.general.ChangeDefaultCharTypeUnsigned>True</avrgcc.compiler.general.ChangeDefaultCharTypeUnsigned>
+        <avrgcc.compiler.general.ChangeDefaultBitFieldUnsigned>True</avrgcc.compiler.general.ChangeDefaultBitFieldUnsigned>
+        <avrgcc.compiler.symbols.DefSymbols>
+          <ListValues>
+            <Value>NDEBUG</Value>
+          </ListValues>
+        </avrgcc.compiler.symbols.DefSymbols>
+        <avrgcc.compiler.directories.IncludePaths>
+          <ListValues>
+            <Value>%24(PackRepoDir)\Atmel\ATmega_DFP\1.4.346\include</Value>
+          </ListValues>
+        </avrgcc.compiler.directories.IncludePaths>
+        <avrgcc.compiler.optimization.level>Optimize for size (-Os)</avrgcc.compiler.optimization.level>
+        <avrgcc.compiler.optimization.AllocateBytesNeededForEnum>True</avrgcc.compiler.optimization.AllocateBytesNeededForEnum>
+        <avrgcc.compiler.warnings.AllWarnings>True</avrgcc.compiler.warnings.AllWarnings>
+        <avrgcc.compiler.warnings.ExtraWarnings>True</avrgcc.compiler.warnings.ExtraWarnings>
+        <avrgcc.compiler.warnings.Pedantic>True</avrgcc.compiler.warnings.Pedantic>
+        <avrgcc.compiler.miscellaneous.OtherFlags>-fno-threadsafe-statics -std=c11</avrgcc.compiler.miscellaneous.OtherFlags>
+        <avrgcccpp.compiler.general.ChangeDefaultCharTypeUnsigned>True</avrgcccpp.compiler.general.ChangeDefaultCharTypeUnsigned>
+        <avrgcccpp.compiler.general.ChangeDefaultBitFieldUnsigned>True</avrgcccpp.compiler.general.ChangeDefaultBitFieldUnsigned>
+        <avrgcccpp.compiler.symbols.DefSymbols>
+          <ListValues>
+            <Value>NDEBUG</Value>
+          </ListValues>
+        </avrgcccpp.compiler.symbols.DefSymbols>
+        <avrgcccpp.compiler.directories.IncludePaths>
+          <ListValues>
+            <Value>%24(PackRepoDir)\Atmel\ATmega_DFP\1.4.346\include</Value>
+          </ListValues>
+        </avrgcccpp.compiler.directories.IncludePaths>
+        <avrgcccpp.compiler.optimization.level>Optimize for size (-Os)</avrgcccpp.compiler.optimization.level>
+        <avrgcccpp.compiler.optimization.AllocateBytesNeededForEnum>True</avrgcccpp.compiler.optimization.AllocateBytesNeededForEnum>
+        <avrgcccpp.compiler.warnings.AllWarnings>True</avrgcccpp.compiler.warnings.AllWarnings>
+        <avrgcccpp.compiler.warnings.Pedantic>True</avrgcccpp.compiler.warnings.Pedantic>
+        <avrgcccpp.compiler.miscellaneous.OtherFlags>-fno-threadsafe-statics -Wextra -std=c++17</avrgcccpp.compiler.miscellaneous.OtherFlags>
+        <avrgcccpp.linker.libraries.Libraries>
+          <ListValues>
+            <Value>libm</Value>
+          </ListValues>
+        </avrgcccpp.linker.libraries.Libraries>
+        <avrgcccpp.assembler.general.IncludePaths>
+          <ListValues>
+            <Value>%24(PackRepoDir)\Atmel\ATmega_DFP\1.4.346\include</Value>
+          </ListValues>
+        </avrgcccpp.assembler.general.IncludePaths>
+      </AvrGccCpp>
+    </ToolchainSettings>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
+    <ToolchainSettings>
+      <AvrGccCpp>
+        <avrgcc.common.Device>-mmcu=atmega328p</avrgcc.common.Device>
+        <avrgcc.common.outputfiles.hex>True</avrgcc.common.outputfiles.hex>
+        <avrgcc.common.outputfiles.lss>True</avrgcc.common.outputfiles.lss>
+        <avrgcc.common.outputfiles.eep>True</avrgcc.common.outputfiles.eep>
+        <avrgcc.common.outputfiles.srec>True</avrgcc.common.outputfiles.srec>
+        <avrgcc.common.outputfiles.usersignatures>False</avrgcc.common.outputfiles.usersignatures>
+        <avrgcc.compiler.general.ChangeDefaultCharTypeUnsigned>True</avrgcc.compiler.general.ChangeDefaultCharTypeUnsigned>
+        <avrgcc.compiler.general.ChangeDefaultBitFieldUnsigned>True</avrgcc.compiler.general.ChangeDefaultBitFieldUnsigned>
+        <avrgcc.compiler.symbols.DefSymbols>
+          <ListValues>
+            <Value>DEBUG</Value>
+          </ListValues>
+        </avrgcc.compiler.symbols.DefSymbols>
+        <avrgcc.compiler.directories.IncludePaths>
+          <ListValues>
+            <Value>%24(PackRepoDir)\Atmel\ATmega_DFP\1.4.346\include</Value>
+          </ListValues>
+        </avrgcc.compiler.directories.IncludePaths>
+        <avrgcc.compiler.optimization.level>Optimize (-O1)</avrgcc.compiler.optimization.level>
+        <avrgcc.compiler.optimization.AllocateBytesNeededForEnum>True</avrgcc.compiler.optimization.AllocateBytesNeededForEnum>
+        <avrgcc.compiler.optimization.DebugLevel>Maximum (-g3)</avrgcc.compiler.optimization.DebugLevel>
+        <avrgcc.compiler.warnings.AllWarnings>True</avrgcc.compiler.warnings.AllWarnings>
+        <avrgcc.compiler.warnings.ExtraWarnings>True</avrgcc.compiler.warnings.ExtraWarnings>
+        <avrgcc.compiler.warnings.Pedantic>True</avrgcc.compiler.warnings.Pedantic>
+        <avrgcc.compiler.miscellaneous.OtherFlags>-fno-threadsafe-statics -std=c11</avrgcc.compiler.miscellaneous.OtherFlags>
+        <avrgcccpp.compiler.general.ChangeDefaultCharTypeUnsigned>True</avrgcccpp.compiler.general.ChangeDefaultCharTypeUnsigned>
+        <avrgcccpp.compiler.general.ChangeDefaultBitFieldUnsigned>True</avrgcccpp.compiler.general.ChangeDefaultBitFieldUnsigned>
+        <avrgcccpp.compiler.symbols.DefSymbols>
+          <ListValues>
+            <Value>DEBUG</Value>
+          </ListValues>
+        </avrgcccpp.compiler.symbols.DefSymbols>
+        <avrgcccpp.compiler.directories.IncludePaths>
+          <ListValues>
+            <Value>%24(PackRepoDir)\Atmel\ATmega_DFP\1.4.346\include</Value>
+          </ListValues>
+        </avrgcccpp.compiler.directories.IncludePaths>
+        <avrgcccpp.compiler.optimization.level>Optimize debugging experience (-Og)</avrgcccpp.compiler.optimization.level>
+        <avrgcccpp.compiler.optimization.AllocateBytesNeededForEnum>True</avrgcccpp.compiler.optimization.AllocateBytesNeededForEnum>
+        <avrgcccpp.compiler.optimization.DebugLevel>Maximum (-g3)</avrgcccpp.compiler.optimization.DebugLevel>
+        <avrgcccpp.compiler.warnings.AllWarnings>True</avrgcccpp.compiler.warnings.AllWarnings>
+        <avrgcccpp.compiler.warnings.Pedantic>True</avrgcccpp.compiler.warnings.Pedantic>
+        <avrgcccpp.compiler.miscellaneous.OtherFlags>-fno-threadsafe-statics -Wextra -std=c++17</avrgcccpp.compiler.miscellaneous.OtherFlags>
+        <avrgcccpp.linker.libraries.Libraries>
+          <ListValues>
+            <Value>libm</Value>
+          </ListValues>
+        </avrgcccpp.linker.libraries.Libraries>
+        <avrgcccpp.assembler.general.IncludePaths>
+          <ListValues>
+            <Value>%24(PackRepoDir)\Atmel\ATmega_DFP\1.4.346\include</Value>
+          </ListValues>
+        </avrgcccpp.assembler.general.IncludePaths>
+        <avrgcccpp.assembler.debugging.DebugLevel>Default (-Wa,-g)</avrgcccpp.assembler.debugging.DebugLevel>
+      </AvrGccCpp>
+    </ToolchainSettings>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="clock.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="ds3231\alarms.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="ds3231\ds3231.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="ds3231\flags.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="ds3231\registers.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="flash\flash.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="i2c\hardware.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="i2c\i2c.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="io\io.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="main.cpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="uart\config.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="uart\hardware.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="uart\hardware0.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="uart\hardware1.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="uart\software.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="uart\uart.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="util\func.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="util\type.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+    <Compile Include="util\util.hpp">
+      <SubType>compile</SubType>
+    </Compile>
+  </ItemGroup>
+  <ItemGroup>
+    <Folder Include="ds3231" />
+    <Folder Include="io" />
+    <Folder Include="flash" />
+    <Folder Include="i2c" />
+    <Folder Include="util" />
+    <Folder Include="uart" />
+  </ItemGroup>
+  <Import Project="$(AVRSTUDIO_EXE_PATH)\\Vs\\Compiler.targets" />
+</Project>
@@ -0,0 +1,188 @@
+#include "clock.hpp"
+
+#include <stdlib.h>
+
+#include "ds3231/ds3231.hpp"
+#include "uart/uart.hpp"
+
+using uart_t = uart::Uart0<>;
+
+REGISTER_UART0_INT_VECTORS(uart_t);
+
+static inline bool isEuDst(const rtc::DateTime &dateTime)
+{
+	constexpr auto calcDstBegin = [](const auto &year) {
+		const auto beginDay = (31 - ((((5 * year) / 4) + 4) % 7));
+		return beginDay;
+	};
+
+	constexpr auto calcDstEnd = [](const auto &year) {
+		const auto endDay = (31 - ((((5 * year) / 4) + 1) % 7));
+		return endDay;
+	};
+
+	if (dateTime.month > 10 || dateTime.month < 3)
+		return false;
+	else if (dateTime.month > 3 && dateTime.month < 10)
+		return true;
+	else if (dateTime.month == 3) {
+		if (dateTime.day > calcDstBegin(dateTime.year)) {
+			return true;
+		} else if (dateTime.day == calcDstBegin(dateTime.year) && dateTime.hour >= 1)
+			return true;
+		return false;
+	}
+	// month == 10
+	if (dateTime.day < calcDstEnd(dateTime.year)) {
+		return true;
+	} else if (dateTime.day == calcDstEnd(dateTime.year) && dateTime.hour < 1)
+		return true;
+	return false;
+}
+
+inline uart_t &operator<<(uart_t &serial, const rtc::DateTime &dateTime)
+{
+	serial.txNumber<uint16_t, 10, 4>(dateTime.year);
+	serial << '-';
+	serial.txNumber<uint8_t, 10, 2>(dateTime.month);
+	serial << '-';
+	serial.txNumber<uint8_t, 10, 2>(dateTime.day);
+	serial << ' ';
+	serial.txNumber<uint8_t, 10, 2>(dateTime.hour);
+	serial << ':';
+	serial.txNumber<uint8_t, 10, 2>(dateTime.minute);
+	serial << ':';
+	serial.txNumber<uint8_t, 10, 2>(dateTime.second);
+	return serial;
+}
+
+static inline void printLocalTime(const rtc::DateTime &dateTime)
+{
+	const auto dst = isEuDst(dateTime);
+
+	uart_t serial;
+	serial << dateTime << (dst ? F(" +2") : F(" +1")) << F("\r\n");
+}
+
+static inline size_t receiveLine(char *buffer, const size_t maxLength)
+{
+	uart_t serial;
+	size_t received = 0;
+
+	while (received < maxLength) {
+		if (serial.rxByte(*reinterpret_cast<uint8_t *>(&buffer[received]))) {
+			++received;
+			if (buffer[received - 1] == '\r' || buffer[received - 1] == '\n')
+				break;
+		}
+	}
+
+	return received;
+}
+
+static inline rtc::DateTime receiveTime()
+{
+	uart_t serial;
+
+	rtc::DateTime dateTime;
+	constexpr auto BUF_LEN = 8;
+	char receiveBuffer[BUF_LEN];
+
+	serial << F("Enter year: ");
+	auto receivedLen = receiveLine(receiveBuffer, BUF_LEN);
+	receiveBuffer[receivedLen] = '\0';
+	dateTime.year = atoi(receiveBuffer);
+
+	serial << F("\r\nEnter month: ");
+	receivedLen = receiveLine(receiveBuffer, BUF_LEN);
+	receiveBuffer[receivedLen] = '\0';
+	dateTime.month = atoi(receiveBuffer);
+
+	serial << F("\r\nEnter date: ");
+	receivedLen = receiveLine(receiveBuffer, BUF_LEN);
+	receiveBuffer[receivedLen] = '\0';
+	dateTime.day = atoi(receiveBuffer);
+
+	serial << F("\r\nEnter hour: ");
+	receivedLen = receiveLine(receiveBuffer, BUF_LEN);
+	receiveBuffer[receivedLen] = '\0';
+	dateTime.hour = atoi(receiveBuffer);
+
+	serial << F("\r\nEnter minute: ");
+	receivedLen = receiveLine(receiveBuffer, BUF_LEN);
+	receiveBuffer[receivedLen] = '\0';
+	dateTime.minute = atoi(receiveBuffer);
+
+	serial << F("\r\nEnter second: ");
+	receivedLen = receiveLine(receiveBuffer, BUF_LEN);
+	receiveBuffer[receivedLen] = '\0';
+	dateTime.second = atoi(receiveBuffer);
+	serial << F("\r\n");
+
+	return dateTime;
+}
+
+int main()
+{
+	uart_t serial;
+	rtc::DS3231<i2c::Hardware<100'000>, false> ds3231;
+	io::Pin<io::P::C3> rtcPwr;
+
+	rtcPwr = false;
+	rtcPwr.dir(io::Dir::OUT);
+
+	rtcPwr = true;
+	_delay_ms(1000);
+
+	ds3231.init();
+	serial.init();
+
+	ds3231.clearAlarm1();
+	ds3231.clearAlarm2();
+
+	rtc::DateTime alarmTime;
+	alarmTime.second = 17;
+	alarmTime.minute = 54;
+
+	ds3231.setAlarm1(alarmTime, rtc::Alarm1Rate::WHEN_S_MATCH);
+	ds3231.setAlarm2(alarmTime, rtc::Alarm2Rate::WHEN_M_MATCH);
+
+	auto oldDate = ds3231.getDateTime();
+
+	while (true) {
+		const auto date = ds3231.getDateTime();
+
+		if (oldDate != date) {
+			oldDate = date;
+			printLocalTime(date);
+		}
+
+		if (ds3231.checkAlarm1()) {
+			serial << F("Alarm1!\r\n");
+			ds3231.clearAlarm1();
+		}
+
+		if (ds3231.checkAlarm2()) {
+			serial << F("Alarm2!\r\n");
+			ds3231.clearAlarm2();
+		}
+
+		uint8_t receivedByte;
+
+		if (serial.rxByte(receivedByte)) {
+			if (receivedByte == 's') {
+				const auto newDate = receiveTime();
+				ds3231.setDateTime(newDate);
+			} else if (receivedByte == '1') {
+				const auto alarm = ds3231.getAlarm1();
+				serial << F("Alarm1: ") << alarm << F("\r\n");
+			} else if (receivedByte == '2') {
+				const auto alarm = ds3231.getAlarm2();
+				serial << F("Alarm2: ") << alarm << F("\r\n");
+			} else
+				serial << F("Invalid input: ") << static_cast<char>(receivedByte) << F("\r\n");
+		}
+	}
+
+	return 0;
+}
@@ -1,3 +0,0 @@
-add_executable(clock main.cpp)
-target_link_libraries(clock PRIVATE ds3231)
-add_custom_command(TARGET clock POST_BUILD COMMAND ${CMAKE_SIZE} $<TARGET_FILE:clock>)
@@ -1,33 +0,0 @@
-#include <ds3231/ds3231.hpp>
-#include <libavr/libavr.hpp>
-
-using namespace avr::literals;
-
-// One source for the tiny85 (open-drain software I2C on the USI pins) and
-// the mega328P (TWI hardware).
-using dev = avr::device<{.clock = 8_MHz}>;
-using bus = dev::i2c<{.frequency = 100_kHz}>;
-using rtc = ds3231::device<bus>;
-using led = dev::output<avr::pb3>;
-
-int main()
-{
-	avr::init<bus, led>();
-
-	if (auto stopped = rtc::oscillator_stopped(); stopped.value_or(false)) {
-		const bool seeded = rtc::write_clock({{2026, 1, 1}, {12, 0, 0}}) &&
-		                    rtc::set_alarm1({}, ds3231::alarm1_rate::once_per_second) &&
-		                    rtc::clear_oscillator_stopped();
-		led::write(seeded);
-	}
-
-	while (true) {
-		if (auto now = rtc::read_clock(); now.has_value()) {
-			led::write(now->second % 2 == 0);
-		}
-		if (auto fired = rtc::alarm1_fired(); fired.value_or(false) && !rtc::clear_alarm1()) {
-			led::clear();
-		}
-		dev::delay<100_ms>();
-	}
-}
@@ -1,108 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="14.0">
-  <PropertyGroup>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectVersion>7.0</ProjectVersion>
-    <ToolchainName>com.Atmel.AVRGCC8.CPP</ToolchainName>
-    <ProjectGuid>7b3e5a41-9c26-4d18-8f52-6a0d31c74be9</ProjectGuid>
-    <avrdevice>ATmega328P</avrdevice>
-    <avrdeviceseries>none</avrdeviceseries>
-    <OutputType>Executable</OutputType>
-    <Language>CPP</Language>
-    <OutputFileName>$(MSBuildProjectName)</OutputFileName>
-    <OutputFileExtension>.elf</OutputFileExtension>
-    <OutputDirectory>$(MSBuildProjectDirectory)\$(Configuration)</OutputDirectory>
-    <AssemblyName>ds3231-atmega328p</AssemblyName>
-    <Name>ds3231-atmega328p</Name>
-    <RootNamespace>ds3231</RootNamespace>
-    <ToolchainFlavour>avr-g++-16.1.0</ToolchainFlavour>
-    <KeepTimersRunning>true</KeepTimersRunning>
-    <OverrideVtor>false</OverrideVtor>
-    <CacheFlash>true</CacheFlash>
-    <ProgFlashFromRam>true</ProgFlashFromRam>
-    <RamSnippetAddress>0x20000000</RamSnippetAddress>
-    <UncachedRange />
-    <preserveEEPROM>true</preserveEEPROM>
-    <OverrideVtorValue>exception_table</OverrideVtorValue>
-    <BootSegment>2</BootSegment>
-    <ResetRule>0</ResetRule>
-    <eraseonlaunchrule>0</eraseonlaunchrule>
-    <EraseKey />
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)' == 'Release' ">
-    <ToolchainSettings>
-      <AvrGccCpp>
-        <avrgcc.common.Device>-mmcu=atmega328p</avrgcc.common.Device>
-        <avrgcc.common.outputfiles.hex>True</avrgcc.common.outputfiles.hex>
-        <avrgcc.common.outputfiles.lss>True</avrgcc.common.outputfiles.lss>
-        <avrgcc.common.outputfiles.eep>True</avrgcc.common.outputfiles.eep>
-        <avrgcc.common.outputfiles.srec>True</avrgcc.common.outputfiles.srec>
-        <avrgcc.common.outputfiles.usersignatures>False</avrgcc.common.outputfiles.usersignatures>
-        <avrgcccpp.compiler.symbols.DefSymbols>
-          <ListValues>
-            <Value>NDEBUG</Value>
-          </ListValues>
-        </avrgcccpp.compiler.symbols.DefSymbols>
-        <avrgcccpp.compiler.directories.IncludePaths>
-          <ListValues>
-            <Value>$(MSBuildProjectDirectory)\..\..\include</Value>
-            <Value>$(MSBuildProjectDirectory)\..\..\libavr\include</Value>
-          </ListValues>
-        </avrgcccpp.compiler.directories.IncludePaths>
-        <avrgcccpp.compiler.optimization.level>Optimize for size (-Os)</avrgcccpp.compiler.optimization.level>
-        <avrgcccpp.compiler.optimization.PrepareFunctionsForGarbageCollection>True</avrgcccpp.compiler.optimization.PrepareFunctionsForGarbageCollection>
-        <avrgcccpp.compiler.optimization.PrepareDataForGarbageCollection>True</avrgcccpp.compiler.optimization.PrepareDataForGarbageCollection>
-        <avrgcccpp.compiler.warnings.AllWarnings>True</avrgcccpp.compiler.warnings.AllWarnings>
-        <avrgcccpp.compiler.miscellaneous.OtherFlags>-std=c++26 -Wextra -mrelax -fno-exceptions -fno-rtti -fno-threadsafe-statics</avrgcccpp.compiler.miscellaneous.OtherFlags>
-        <avrgcccpp.linker.optimization.GarbageCollectUnusedSections>True</avrgcccpp.linker.optimization.GarbageCollectUnusedSections>
-        <avrgcccpp.linker.miscellaneous.LinkerFlags>-mrelax</avrgcccpp.linker.miscellaneous.LinkerFlags>
-      </AvrGccCpp>
-    </ToolchainSettings>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
-    <ToolchainSettings>
-      <AvrGccCpp>
-        <avrgcc.common.Device>-mmcu=atmega328p</avrgcc.common.Device>
-        <avrgcc.common.outputfiles.hex>True</avrgcc.common.outputfiles.hex>
-        <avrgcc.common.outputfiles.lss>True</avrgcc.common.outputfiles.lss>
-        <avrgcc.common.outputfiles.eep>True</avrgcc.common.outputfiles.eep>
-        <avrgcc.common.outputfiles.srec>True</avrgcc.common.outputfiles.srec>
-        <avrgcc.common.outputfiles.usersignatures>False</avrgcc.common.outputfiles.usersignatures>
-        <avrgcccpp.compiler.symbols.DefSymbols>
-          <ListValues>
-            <Value>DEBUG</Value>
-          </ListValues>
-        </avrgcccpp.compiler.symbols.DefSymbols>
-        <avrgcccpp.compiler.directories.IncludePaths>
-          <ListValues>
-            <Value>$(MSBuildProjectDirectory)\..\..\include</Value>
-            <Value>$(MSBuildProjectDirectory)\..\..\libavr\include</Value>
-          </ListValues>
-        </avrgcccpp.compiler.directories.IncludePaths>
-        <avrgcccpp.compiler.optimization.level>Optimize debugging experience (-Og)</avrgcccpp.compiler.optimization.level>
-        <avrgcccpp.compiler.optimization.PrepareFunctionsForGarbageCollection>True</avrgcccpp.compiler.optimization.PrepareFunctionsForGarbageCollection>
-        <avrgcccpp.compiler.optimization.PrepareDataForGarbageCollection>True</avrgcccpp.compiler.optimization.PrepareDataForGarbageCollection>
-        <avrgcccpp.compiler.warnings.AllWarnings>True</avrgcccpp.compiler.warnings.AllWarnings>
-        <avrgcccpp.compiler.miscellaneous.OtherFlags>-std=c++26 -Wextra -mrelax -fno-exceptions -fno-rtti -fno-threadsafe-statics -gdwarf-4</avrgcccpp.compiler.miscellaneous.OtherFlags>
-        <avrgcccpp.linker.optimization.GarbageCollectUnusedSections>True</avrgcccpp.linker.optimization.GarbageCollectUnusedSections>
-        <avrgcccpp.linker.miscellaneous.LinkerFlags>-mrelax</avrgcccpp.linker.miscellaneous.LinkerFlags>
-      </AvrGccCpp>
-    </ToolchainSettings>
-  </PropertyGroup>
-  <ItemGroup>
-    <Compile Include="..\..\example\main.cpp">
-      <SubType>compile</SubType>
-      <Link>example\main.cpp</Link>
-    </Compile>
-    <Compile Include="..\..\include\ds3231\ds3231.hpp">
-      <SubType>compile</SubType>
-      <Link>include\ds3231\ds3231.hpp</Link>
-    </Compile>
-  </ItemGroup>
-  <ItemGroup>
-    <Folder Include="example" />
-    <Folder Include="include" />
-    <Folder Include="include\ds3231" />
-  </ItemGroup>
-  <Import Project="$(AVRSTUDIO_EXE_PATH)\Vs\Compiler.targets" />
-</Project>
@@ -1,108 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<Project DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003" ToolsVersion="14.0">
-  <PropertyGroup>
-    <SchemaVersion>2.0</SchemaVersion>
-    <ProjectVersion>7.0</ProjectVersion>
-    <ToolchainName>com.Atmel.AVRGCC8.CPP</ToolchainName>
-    <ProjectGuid>1d84c0f7-52b9-4a63-b7e1-9f2c48d5a306</ProjectGuid>
-    <avrdevice>ATtiny85</avrdevice>
-    <avrdeviceseries>none</avrdeviceseries>
-    <OutputType>Executable</OutputType>
-    <Language>CPP</Language>
-    <OutputFileName>$(MSBuildProjectName)</OutputFileName>
-    <OutputFileExtension>.elf</OutputFileExtension>
-    <OutputDirectory>$(MSBuildProjectDirectory)\$(Configuration)</OutputDirectory>
-    <AssemblyName>ds3231-attiny85</AssemblyName>
-    <Name>ds3231-attiny85</Name>
-    <RootNamespace>ds3231</RootNamespace>
-    <ToolchainFlavour>avr-g++-16.1.0</ToolchainFlavour>
-    <KeepTimersRunning>true</KeepTimersRunning>
-    <OverrideVtor>false</OverrideVtor>
-    <CacheFlash>true</CacheFlash>
-    <ProgFlashFromRam>true</ProgFlashFromRam>
-    <RamSnippetAddress>0x20000000</RamSnippetAddress>
-    <UncachedRange />
-    <preserveEEPROM>true</preserveEEPROM>
-    <OverrideVtorValue>exception_table</OverrideVtorValue>
-    <BootSegment>2</BootSegment>
-    <ResetRule>0</ResetRule>
-    <eraseonlaunchrule>0</eraseonlaunchrule>
-    <EraseKey />
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)' == 'Release' ">
-    <ToolchainSettings>
-      <AvrGccCpp>
-        <avrgcc.common.Device>-mmcu=attiny85</avrgcc.common.Device>
-        <avrgcc.common.outputfiles.hex>True</avrgcc.common.outputfiles.hex>
-        <avrgcc.common.outputfiles.lss>True</avrgcc.common.outputfiles.lss>
-        <avrgcc.common.outputfiles.eep>True</avrgcc.common.outputfiles.eep>
-        <avrgcc.common.outputfiles.srec>True</avrgcc.common.outputfiles.srec>
-        <avrgcc.common.outputfiles.usersignatures>False</avrgcc.common.outputfiles.usersignatures>
-        <avrgcccpp.compiler.symbols.DefSymbols>
-          <ListValues>
-            <Value>NDEBUG</Value>
-          </ListValues>
-        </avrgcccpp.compiler.symbols.DefSymbols>
-        <avrgcccpp.compiler.directories.IncludePaths>
-          <ListValues>
-            <Value>$(MSBuildProjectDirectory)\..\..\include</Value>
-            <Value>$(MSBuildProjectDirectory)\..\..\libavr\include</Value>
-          </ListValues>
-        </avrgcccpp.compiler.directories.IncludePaths>
-        <avrgcccpp.compiler.optimization.level>Optimize for size (-Os)</avrgcccpp.compiler.optimization.level>
-        <avrgcccpp.compiler.optimization.PrepareFunctionsForGarbageCollection>True</avrgcccpp.compiler.optimization.PrepareFunctionsForGarbageCollection>
-        <avrgcccpp.compiler.optimization.PrepareDataForGarbageCollection>True</avrgcccpp.compiler.optimization.PrepareDataForGarbageCollection>
-        <avrgcccpp.compiler.warnings.AllWarnings>True</avrgcccpp.compiler.warnings.AllWarnings>
-        <avrgcccpp.compiler.miscellaneous.OtherFlags>-std=c++26 -Wextra -mrelax -fno-exceptions -fno-rtti -fno-threadsafe-statics</avrgcccpp.compiler.miscellaneous.OtherFlags>
-        <avrgcccpp.linker.optimization.GarbageCollectUnusedSections>True</avrgcccpp.linker.optimization.GarbageCollectUnusedSections>
-        <avrgcccpp.linker.miscellaneous.LinkerFlags>-mrelax</avrgcccpp.linker.miscellaneous.LinkerFlags>
-      </AvrGccCpp>
-    </ToolchainSettings>
-  </PropertyGroup>
-  <PropertyGroup Condition=" '$(Configuration)' == 'Debug' ">
-    <ToolchainSettings>
-      <AvrGccCpp>
-        <avrgcc.common.Device>-mmcu=attiny85</avrgcc.common.Device>
-        <avrgcc.common.outputfiles.hex>True</avrgcc.common.outputfiles.hex>
-        <avrgcc.common.outputfiles.lss>True</avrgcc.common.outputfiles.lss>
-        <avrgcc.common.outputfiles.eep>True</avrgcc.common.outputfiles.eep>
-        <avrgcc.common.outputfiles.srec>True</avrgcc.common.outputfiles.srec>
-        <avrgcc.common.outputfiles.usersignatures>False</avrgcc.common.outputfiles.usersignatures>
-        <avrgcccpp.compiler.symbols.DefSymbols>
-          <ListValues>
-            <Value>DEBUG</Value>
-          </ListValues>
-        </avrgcccpp.compiler.symbols.DefSymbols>
-        <avrgcccpp.compiler.directories.IncludePaths>
-          <ListValues>
-            <Value>$(MSBuildProjectDirectory)\..\..\include</Value>
-            <Value>$(MSBuildProjectDirectory)\..\..\libavr\include</Value>
-          </ListValues>
-        </avrgcccpp.compiler.directories.IncludePaths>
-        <avrgcccpp.compiler.optimization.level>Optimize debugging experience (-Og)</avrgcccpp.compiler.optimization.level>
-        <avrgcccpp.compiler.optimization.PrepareFunctionsForGarbageCollection>True</avrgcccpp.compiler.optimization.PrepareFunctionsForGarbageCollection>
-        <avrgcccpp.compiler.optimization.PrepareDataForGarbageCollection>True</avrgcccpp.compiler.optimization.PrepareDataForGarbageCollection>
-        <avrgcccpp.compiler.warnings.AllWarnings>True</avrgcccpp.compiler.warnings.AllWarnings>
-        <avrgcccpp.compiler.miscellaneous.OtherFlags>-std=c++26 -Wextra -mrelax -fno-exceptions -fno-rtti -fno-threadsafe-statics -gdwarf-4</avrgcccpp.compiler.miscellaneous.OtherFlags>
-        <avrgcccpp.linker.optimization.GarbageCollectUnusedSections>True</avrgcccpp.linker.optimization.GarbageCollectUnusedSections>
-        <avrgcccpp.linker.miscellaneous.LinkerFlags>-mrelax</avrgcccpp.linker.miscellaneous.LinkerFlags>
-      </AvrGccCpp>
-    </ToolchainSettings>
-  </PropertyGroup>
-  <ItemGroup>
-    <Compile Include="..\..\example\main.cpp">
-      <SubType>compile</SubType>
-      <Link>example\main.cpp</Link>
-    </Compile>
-    <Compile Include="..\..\include\ds3231\ds3231.hpp">
-      <SubType>compile</SubType>
-      <Link>include\ds3231\ds3231.hpp</Link>
-    </Compile>
-  </ItemGroup>
-  <ItemGroup>
-    <Folder Include="example" />
-    <Folder Include="include" />
-    <Folder Include="include\ds3231" />
-  </ItemGroup>
-  <Import Project="$(AVRSTUDIO_EXE_PATH)\Vs\Compiler.targets" />
-</Project>
@@ -1,28 +0,0 @@
-
-Microsoft Visual Studio Solution File, Format Version 12.00
-# Atmel Studio Solution File, Format Version 11.00
-VisualStudioVersion = 14.0.23107.0
-MinimumVisualStudioVersion = 10.0.40219.1
-Project("{E66E83B9-2572-4076-B26E-6BE79FF3018A}") = "ds3231-atmega328p", "atmega328p\ds3231-atmega328p.cppproj", "{7B3E5A41-9C26-4D18-8F52-6A0D31C74BE9}"
-EndProject
-Project("{E66E83B9-2572-4076-B26E-6BE79FF3018A}") = "ds3231-attiny85", "attiny85\ds3231-attiny85.cppproj", "{1D84C0F7-52B9-4A63-B7E1-9F2C48D5A306}"
-EndProject
-Global
-	GlobalSection(SolutionConfigurationPlatforms) = preSolution
-		Debug|AVR = Debug|AVR
-		Release|AVR = Release|AVR
-	EndGlobalSection
-	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{7B3E5A41-9C26-4D18-8F52-6A0D31C74BE9}.Debug|AVR.ActiveCfg = Debug|AVR
-		{7B3E5A41-9C26-4D18-8F52-6A0D31C74BE9}.Debug|AVR.Build.0 = Debug|AVR
-		{7B3E5A41-9C26-4D18-8F52-6A0D31C74BE9}.Release|AVR.ActiveCfg = Release|AVR
-		{7B3E5A41-9C26-4D18-8F52-6A0D31C74BE9}.Release|AVR.Build.0 = Release|AVR
-		{1D84C0F7-52B9-4A63-B7E1-9F2C48D5A306}.Debug|AVR.ActiveCfg = Debug|AVR
-		{1D84C0F7-52B9-4A63-B7E1-9F2C48D5A306}.Debug|AVR.Build.0 = Debug|AVR
-		{1D84C0F7-52B9-4A63-B7E1-9F2C48D5A306}.Release|AVR.ActiveCfg = Release|AVR
-		{1D84C0F7-52B9-4A63-B7E1-9F2C48D5A306}.Release|AVR.Build.0 = Release|AVR
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
-	EndGlobalSection
-EndGlobal
@@ -1,399 +0,0 @@
-#pragma once
-
-#include <array>
-#include <cstddef>
-#include <cstdint>
-#include <expected>
-#include <span>
-#include <utility>
-
-#include <libavr/i2c.hpp>
-
-namespace ds3231 {
-
-using avr::i2c::error;
-using avr::i2c::status;
-template <typename T>
-using result = std::expected<T, error>;
-
-struct date {
-	std::uint16_t year; // 2000..2099
-	std::uint8_t month; // 1..12
-	std::uint8_t day;   // 1..31 (weekday 1..7 in weekday-alarm reads)
-	friend constexpr bool operator==(const date &, const date &) = default;
-};
-
-struct time_of_day {
-	std::uint8_t hour; // 0..23
-	std::uint8_t minute;
-	std::uint8_t second;
-	friend constexpr bool operator==(const time_of_day &, const time_of_day &) = default;
-};
-
-struct date_time : date, time_of_day {
-	friend constexpr bool operator==(const date_time &, const date_time &) = default;
-};
-
-// Alarm match rates (datasheet Table 2). Alarm 2 has no seconds register
-// and fires at :00 of the matching minute.
-enum class alarm1_rate : std::uint8_t {
-	once_per_second = 0b01111,
-	seconds_match = 0b01110,
-	minutes_seconds_match = 0b01100,
-	time_match = 0b01000,
-	date_time_match = 0b00000,
-	weekday_time_match = 0b10000,
-};
-
-// Who owns the weekday register. The device counts 1..7 with a free epoch and
-// maintains nothing itself, so either this driver derives it from the date on
-// every write, or the register belongs to the program and no write here
-// touches it - which is what a caller that assigns its own meaning to those
-// seven values needs.
-enum class weekday_source : std::uint8_t { computed, external };
-
-// Whether arming an alarm also wires its INT/SQW output. `off` is not
-// silence about the bit - it clears A1IE/A2IE, so an alarm armed with the
-// interrupt on and re-armed with it off stops driving the pin.
-enum class alarm_interrupt : std::uint8_t { off, on };
-
-enum class alarm2_rate : std::uint8_t {
-	once_per_minute = 0b0111,
-	minutes_match = 0b0110,
-	time_match = 0b0100,
-	date_time_match = 0b0000,
-	weekday_time_match = 0b1000,
-};
-
-namespace detail {
-
-// The register map, datasheet 19-5170 Figure 1.
-inline constexpr std::uint8_t reg_seconds = 0x00, reg_day = 0x03, reg_date = 0x04;
-inline constexpr std::uint8_t reg_alarm1 = 0x07, reg_alarm2 = 0x0b;
-inline constexpr std::uint8_t reg_control = 0x0e, reg_status = 0x0f, reg_temp = 0x11;
-
-inline constexpr std::uint8_t alarm_mask = 0x80, day_of_week = 0x40;
-inline constexpr std::uint8_t twelve_hour = 0x40, pm = 0x20;
-inline constexpr std::uint8_t century = 0x80;
-inline constexpr std::uint8_t a1ie = 0x01, a2ie = 0x02, intcn = 0x04;
-inline constexpr std::uint8_t a1f = 0x01, a2f = 0x02, osf = 0x80;
-
-inline constexpr std::uint16_t first_year = 2000;
-
-constexpr std::uint8_t to_bcd(std::uint8_t value)
-{
-	return static_cast<std::uint8_t>(((value / 10) << 4) | (value % 10));
-}
-
-constexpr std::uint8_t from_bcd(std::uint8_t value)
-{
-	return static_cast<std::uint8_t>((value >> 4) * 10 + (value & 0x0f));
-}
-
-// Writes always use the 24-hour form; reads accept either.
-constexpr std::uint8_t hours_from_reg(std::uint8_t reg)
-{
-	if (reg & twelve_hour) {
-		const auto hour = from_bcd(reg & ~(alarm_mask | twelve_hour | pm));
-		const bool after_noon = reg & pm;
-		if (hour == 12) {
-			return after_noon ? 12 : 0;
-		}
-		return static_cast<std::uint8_t>(after_noon ? hour + 12 : hour);
-	}
-	return from_bcd(reg & ~(alarm_mask | twelve_hour));
-}
-
-// Sakamoto's method; the device counts weekdays 1..7 with a free epoch,
-// this maps Sunday to 1.
-constexpr std::uint8_t weekday(std::uint16_t year, std::uint8_t month, std::uint8_t day)
-{
-	static constexpr auto offsets = std::to_array<std::uint8_t>({0, 3, 2, 5, 0, 3, 5, 1, 4, 6, 2, 4});
-	if (month < 3) {
-		--year;
-	}
-	return static_cast<std::uint8_t>((year + year / 4 - year / 100 + year / 400 + offsets[month - 1] + day) % 7 + 1);
-}
-
-constexpr time_of_day time_from_registers(std::span<const std::uint8_t> raw)
-{
-	return {hours_from_reg(raw[2]), from_bcd(raw[1] & ~alarm_mask), from_bcd(raw[0] & ~alarm_mask)};
-}
-
-// Rate bit n is the mask bit of the alarm's n-th register and the bit above
-// them is DY/DT (Table 2). Alarm 2 has no seconds register, so its registers
-// are alarm 1's last three.
-inline constexpr std::size_t alarm1_registers = reg_alarm2 - reg_alarm1;
-inline constexpr std::size_t alarm2_registers = reg_control - reg_alarm2;
-
-template <std::size_t Count>
-constexpr std::array<std::uint8_t, Count> alarm_registers(const date_time &at, std::uint8_t rate)
-{
-	const bool weekday_mode = (rate >> Count) & 1;
-	const std::array<std::uint8_t, alarm1_registers> fields{
-	    to_bcd(at.second),
-	    to_bcd(at.minute),
-	    to_bcd(at.hour),
-	    weekday_mode ? static_cast<std::uint8_t>(day_of_week | at.day) : to_bcd(at.day),
-	};
-	return [&]<std::size_t... I>(std::index_sequence<I...>) {
-		return std::array{
-		    static_cast<std::uint8_t>(fields[alarm1_registers - Count + I] | (((rate >> I) & 1) ? alarm_mask : 0))...};
-	}(std::make_index_sequence<Count>{});
-}
-
-constexpr std::uint8_t control_with(std::uint8_t control, std::uint8_t enable_bit, alarm_interrupt interrupt)
-{
-	if (interrupt == alarm_interrupt::on) {
-		return static_cast<std::uint8_t>(control | intcn | enable_bit);
-	}
-	return static_cast<std::uint8_t>(control & ~enable_bit);
-}
-
-// A1F and A2F ignore a written 1, so writing the other one as 1 cannot lose it.
-constexpr std::uint8_t status_clearing(std::uint8_t status, std::uint8_t flag)
-{
-	return static_cast<std::uint8_t>((status | a1f | a2f) & ~flag);
-}
-
-} // namespace detail
-
-// The one bus address a DS3231 answers on - hardwired in the die, no
-// address pins (datasheet 19-5170, "I2C interface").
-inline constexpr std::uint8_t bus_address = 0x68;
-
-// Maxim DS3231 RTC on any libavr i2c bus: the master role is taken from the
-// bus's own resolution, so a declared `dev::i2c<...>` is handed over whole.
-// Every read is one bus transaction; errors surface as std::expected. Weekday
-// registers are derived from the date unless the program owns them.
-template <typename Bus, weekday_source Weekday = weekday_source::computed>
-class device {
-	static constexpr bool computes_weekday = Weekday == weekday_source::computed;
-
-	using dev = avr::i2c::device<typename Bus::master, bus_address>;
-
-  public:
-	[[nodiscard]] static result<date_time> read_clock()
-	{
-		std::array<std::uint8_t, 7> raw;
-		if (auto s = dev::read_regs(detail::reg_seconds, raw); !s) {
-			return std::unexpected(s.error());
-		}
-		date_time now;
-		static_cast<time_of_day &>(now) = detail::time_from_registers(raw);
-		now.day = detail::from_bcd(raw[4]);
-		now.month = detail::from_bcd(raw[5] & ~detail::century);
-		now.year = static_cast<std::uint16_t>(detail::first_year + detail::from_bcd(raw[6]));
-		return now;
-	}
-
-	[[nodiscard]] static result<date> read_date()
-	{
-		auto now = read_clock();
-		if (!now) {
-			return std::unexpected(now.error());
-		}
-		return static_cast<date>(*now);
-	}
-
-	[[nodiscard]] static result<time_of_day> read_time()
-	{
-		std::array<std::uint8_t, 3> raw;
-		if (auto s = dev::read_regs(detail::reg_seconds, raw); !s) {
-			return std::unexpected(s.error());
-		}
-		return detail::time_from_registers(raw);
-	}
-
-	[[nodiscard]] static status write_clock(const date_time &now)
-	{
-		if constexpr (computes_weekday) {
-			std::array raw{detail::to_bcd(now.second),
-			               detail::to_bcd(now.minute),
-			               detail::to_bcd(now.hour),
-			               detail::weekday(now.year, now.month, now.day),
-			               detail::to_bcd(now.day),
-			               detail::to_bcd(now.month),
-			               detail::to_bcd(static_cast<std::uint8_t>(now.year - detail::first_year))};
-			return dev::write_regs(detail::reg_seconds, raw);
-		} else {
-			// Two transactions, because the weekday register sits between the
-			// time and the date and this mode may not write it.
-			if (auto s = write_time(now); !s) {
-				return s;
-			}
-			return write_date(now);
-		}
-	}
-
-	[[nodiscard]] static status write_date(const date &value)
-	{
-		const auto year = detail::to_bcd(static_cast<std::uint8_t>(value.year - detail::first_year));
-		if constexpr (computes_weekday) {
-			std::array raw{detail::weekday(value.year, value.month, value.day), detail::to_bcd(value.day),
-			               detail::to_bcd(value.month), year};
-			return dev::write_regs(detail::reg_day, raw);
-		} else {
-			std::array raw{detail::to_bcd(value.day), detail::to_bcd(value.month), year};
-			return dev::write_regs(detail::reg_date, raw);
-		}
-	}
-
-	[[nodiscard]] static status write_time(const time_of_day &value)
-	{
-		std::array raw{detail::to_bcd(value.second), detail::to_bcd(value.minute), detail::to_bcd(value.hour)};
-		return dev::write_regs(detail::reg_seconds, raw);
-	}
-
-	// Alarm times use .day as the date of month, or as weekday 1..7 with
-	// the weekday_time_match rates.
-	[[nodiscard]] static status set_alarm1(const date_time &at, alarm1_rate rate,
-	                                       alarm_interrupt interrupt = alarm_interrupt::on)
-	{
-		return set_alarm<detail::alarm1_registers>(detail::reg_alarm1, at, std::to_underlying(rate), detail::a1ie,
-		                                           interrupt);
-	}
-
-	[[nodiscard]] static status set_alarm2(const date_time &at, alarm2_rate rate,
-	                                       alarm_interrupt interrupt = alarm_interrupt::on)
-	{
-		return set_alarm<detail::alarm2_registers>(detail::reg_alarm2, at, std::to_underlying(rate), detail::a2ie,
-		                                           interrupt);
-	}
-
-	[[nodiscard]] static result<date_time> read_alarm1()
-	{
-		return read_alarm<detail::alarm1_registers>(detail::reg_alarm1);
-	}
-
-	[[nodiscard]] static result<date_time> read_alarm2()
-	{
-		return read_alarm<detail::alarm2_registers>(detail::reg_alarm2);
-	}
-
-	[[nodiscard]] static result<bool> alarm1_fired()
-	{
-		return flag_set(detail::a1f);
-	}
-
-	[[nodiscard]] static result<bool> alarm2_fired()
-	{
-		return flag_set(detail::a2f);
-	}
-
-	[[nodiscard]] static status clear_alarm1()
-	{
-		return clear_flag(detail::a1f);
-	}
-
-	[[nodiscard]] static status clear_alarm2()
-	{
-		return clear_flag(detail::a2f);
-	}
-
-	// True after the oscillator was ever stopped (first power-up, battery
-	// ran out): the clock needs to be set.
-	[[nodiscard]] static result<bool> oscillator_stopped()
-	{
-		return flag_set(detail::osf);
-	}
-
-	[[nodiscard]] static status clear_oscillator_stopped()
-	{
-		return clear_flag(detail::osf);
-	}
-
-	// Die temperature in quarter C (updated every 64 s by the device).
-	[[nodiscard]] static result<std::int16_t> temperature_quarters()
-	{
-		std::array<std::uint8_t, 2> raw;
-		if (auto s = dev::read_regs(detail::reg_temp, raw); !s) {
-			return std::unexpected(s.error());
-		}
-		return static_cast<std::int16_t>((static_cast<std::int16_t>(static_cast<std::int8_t>(raw[0])) << 2) |
-		                                 (raw[1] >> 6));
-	}
-
-	// The alarms' INT/SQW wiring on its own, for a caller that arms once and
-	// mutes later. Alarm 1 and alarm 2 share INTCN, so muting one leaves the
-	// other's route intact.
-	[[nodiscard]] static status listen_alarm1()
-	{
-		return set_alarm_interrupt(detail::a1ie, alarm_interrupt::on);
-	}
-
-	[[nodiscard]] static status mute_alarm1()
-	{
-		return set_alarm_interrupt(detail::a1ie, alarm_interrupt::off);
-	}
-
-	[[nodiscard]] static status listen_alarm2()
-	{
-		return set_alarm_interrupt(detail::a2ie, alarm_interrupt::on);
-	}
-
-	[[nodiscard]] static status mute_alarm2()
-	{
-		return set_alarm_interrupt(detail::a2ie, alarm_interrupt::off);
-	}
-
-  private:
-	template <std::size_t Count>
-	static status set_alarm(std::uint8_t reg, const date_time &at, std::uint8_t rate, std::uint8_t enable_bit,
-	                        alarm_interrupt interrupt)
-	{
-		if (auto s = dev::write_regs(reg, detail::alarm_registers<Count>(at, rate)); !s) {
-			return s;
-		}
-		return set_alarm_interrupt(enable_bit, interrupt);
-	}
-
-	template <std::size_t Count>
-	static result<date_time> read_alarm(std::uint8_t reg)
-	{
-		std::array<std::uint8_t, Count> raw;
-		if (auto s = dev::read_regs(reg, raw); !s) {
-			return std::unexpected(s.error());
-		}
-		constexpr auto first = detail::alarm1_registers - Count;
-		date_time at{};
-		if constexpr (first == 0) {
-			at.second = detail::from_bcd(raw[0] & ~detail::alarm_mask);
-		}
-		at.minute = detail::from_bcd(raw[1 - first] & ~detail::alarm_mask);
-		at.hour = detail::hours_from_reg(raw[2 - first]);
-		at.day = detail::from_bcd(raw[3 - first] & ~(detail::alarm_mask | detail::day_of_week));
-		return at;
-	}
-
-	// INTCN routes the alarms to INT/SQW, so arming an alarm's interrupt takes
-	// the pin and muting it gives up only that alarm's claim on it.
-	static status set_alarm_interrupt(std::uint8_t enable_bit, alarm_interrupt interrupt)
-	{
-		auto control = dev::read_reg(detail::reg_control);
-		if (!control) {
-			return std::unexpected(control.error());
-		}
-		return dev::write_reg(detail::reg_control, detail::control_with(*control, enable_bit, interrupt));
-	}
-
-	static result<bool> flag_set(std::uint8_t bit)
-	{
-		auto flags = dev::read_reg(detail::reg_status);
-		if (!flags) {
-			return std::unexpected(flags.error());
-		}
-		return (*flags & bit) != 0;
-	}
-
-	static status clear_flag(std::uint8_t bit)
-	{
-		auto flags = dev::read_reg(detail::reg_status);
-		if (!flags) {
-			return std::unexpected(flags.error());
-		}
-		return dev::write_reg(detail::reg_status, detail::status_clearing(*flags, bit));
-	}
-};
-
-} // namespace ds3231
@@ -1,25 +0,0 @@
-libavr_format_test()
-
-# The example's size is stated in the README, per chip, and a library advance
-# that moves it silently is what this catches.
-if(LIBAVR_MCU STREQUAL "atmega328p")
-	libavr_size_claim_test(clock 1462)
-elseif(LIBAVR_MCU STREQUAL "attiny85")
-	libavr_size_claim_test(clock 1256)
-endif()
-
-# The README says the two modes emit the same image, and only a tree with
-# both built can say whether they do.
-libavr_mode_identity_test(clock)
-
-# The battery is a compile: a static_assert that fails is the failure. It is a
-# target rather than only a ctest so a plain build catches a regression too.
-add_library(consteval_tests OBJECT consteval.cpp)
-target_link_libraries(consteval_tests PRIVATE ds3231)
-
-add_test(NAME ds3231.consteval
-         COMMAND ${CMAKE_COMMAND} --build ${CMAKE_BINARY_DIR} --target consteval_tests)
-
-# A check this host cannot run reads as Skipped rather than Failed: the marker
-# a stubbed launcher prints, over every test registered here.
-libavr_skip_unverified()
@@ -1,111 +0,0 @@
-// Compile-only battery, built with the cross compiler so the target's 16-bit
-// int is exercised. Everything in this driver that is arithmetic rather than a
-// bus transaction lives here: the BCD both ways, the hours register's two
-// formats, Sakamoto's weekday, the alarm registers each rate writes, and the
-// control and status values written back.
-
-#include <array>
-#include <cstdint>
-
-#include <ds3231/ds3231.hpp>
-
-namespace {
-
-using ds3231::detail::from_bcd;
-using ds3231::detail::hours_from_reg;
-using ds3231::detail::to_bcd;
-
-// BCD is a round trip over every value the registers hold, and the encoding is
-// the datasheet's: tens in the high nibble, units in the low one.
-consteval bool bcd_round_trips()
-{
-	for (std::uint8_t value = 0; value < 100; ++value) {
-		const std::uint8_t packed = to_bcd(value);
-		if (from_bcd(packed) != value) {
-			return false;
-		}
-		if ((packed >> 4) != value / 10 || (packed & 0x0f) != value % 10) {
-			return false;
-		}
-	}
-	return true;
-}
-static_assert(bcd_round_trips());
-
-// The hours register (19-5170 Table 1): bit 6 selects 12-hour mode and bit 5
-// is then PM. Both noons and both midnights are the cases a naive decode gets
-// wrong - 12 AM is hour 0 and 12 PM is hour 12, neither of which is 12 + 12.
-static_assert(hours_from_reg(to_bcd(0)) == 0);   // 24-hour midnight
-static_assert(hours_from_reg(to_bcd(13)) == 13); // 24-hour afternoon
-static_assert(hours_from_reg(to_bcd(23)) == 23);
-static_assert(hours_from_reg(0x40 | to_bcd(12)) == 0);         // 12 AM
-static_assert(hours_from_reg(0x40 | 0x20 | to_bcd(12)) == 12); // 12 PM
-static_assert(hours_from_reg(0x40 | to_bcd(1)) == 1);          // 1 AM
-static_assert(hours_from_reg(0x40 | 0x20 | to_bcd(1)) == 13);  // 1 PM
-static_assert(hours_from_reg(0x40 | 0x20 | to_bcd(11)) == 23); // 11 PM
-
-// Sakamoto's method, against dates a calendar can be checked against rather
-// than against this implementation run twice. Sunday is 1.
-using ds3231::detail::weekday;
-static_assert(weekday(2000, 1, 1) == 7);  // Saturday
-static_assert(weekday(2024, 1, 1) == 2);  // Monday
-static_assert(weekday(2024, 2, 29) == 5); // Thursday, the leap day
-static_assert(weekday(2024, 3, 1) == 6);  // Friday, the day after it
-static_assert(weekday(2100, 3, 1) == 2);  // Monday - 2100 is not a leap year
-static_assert(weekday(2026, 8, 12) == 4); // Wednesday
-
-// The alarm registers each rate writes (19-5170 Table 2): bit 7 of the n-th
-// register is AxM(n+1), and DY/DT is bit 6 of the day register. Rows are read
-// off the table, so a slip in the rate values or in their distribution over
-// the registers arms the wrong alarm here first.
-using ds3231::alarm1_rate;
-using ds3231::alarm2_rate;
-using ds3231::detail::alarm_registers;
-constexpr ds3231::date_time at{{2026, 1, 15}, {12, 30, 45}};
-constexpr ds3231::date_time on_weekday{{2026, 1, 3}, {7, 5, 0}};
-
-template <typename Rate>
-constexpr auto alarm1(const ds3231::date_time &value, Rate rate)
-{
-	return alarm_registers<ds3231::detail::alarm1_registers>(value, static_cast<std::uint8_t>(rate));
-}
-
-template <typename Rate>
-constexpr auto alarm2(const ds3231::date_time &value, Rate rate)
-{
-	return alarm_registers<ds3231::detail::alarm2_registers>(value, static_cast<std::uint8_t>(rate));
-}
-
-static_assert(alarm1(at, alarm1_rate::once_per_second) == std::to_array<std::uint8_t>({0xc5, 0xb0, 0x92, 0x95}));
-static_assert(alarm1(at, alarm1_rate::seconds_match) == std::to_array<std::uint8_t>({0x45, 0xb0, 0x92, 0x95}));
-static_assert(alarm1(at, alarm1_rate::minutes_seconds_match) == std::to_array<std::uint8_t>({0x45, 0x30, 0x92, 0x95}));
-static_assert(alarm1(at, alarm1_rate::time_match) == std::to_array<std::uint8_t>({0x45, 0x30, 0x12, 0x95}));
-static_assert(alarm1(at, alarm1_rate::date_time_match) == std::to_array<std::uint8_t>({0x45, 0x30, 0x12, 0x15}));
-static_assert(alarm1(on_weekday, alarm1_rate::weekday_time_match) ==
-              std::to_array<std::uint8_t>({0x00, 0x05, 0x07, 0x43}));
-
-static_assert(alarm2(at, alarm2_rate::once_per_minute) == std::to_array<std::uint8_t>({0xb0, 0x92, 0x95}));
-static_assert(alarm2(at, alarm2_rate::minutes_match) == std::to_array<std::uint8_t>({0x30, 0x92, 0x95}));
-static_assert(alarm2(at, alarm2_rate::time_match) == std::to_array<std::uint8_t>({0x30, 0x12, 0x95}));
-static_assert(alarm2(at, alarm2_rate::date_time_match) == std::to_array<std::uint8_t>({0x30, 0x12, 0x15}));
-static_assert(alarm2(on_weekday, alarm2_rate::weekday_time_match) == std::to_array<std::uint8_t>({0x05, 0x07, 0x43}));
-
-// A1F and A2F ignore a written 1 and OSF holds until written 0 (19-5170,
-// Status Register): clearing one alarm must write the other as 1, or an alarm
-// firing between the read and the write is lost.
-using ds3231::detail::status_clearing;
-static_assert(status_clearing(0x00, 0x01) == 0x02); // A2F set after the read survives
-static_assert(status_clearing(0x03, 0x02) == 0x01);
-static_assert(status_clearing(0x88, 0x01) == 0x8a); // OSF and EN32kHz kept as read
-static_assert(status_clearing(0x80, 0x80) == 0x03);
-
-// BBSQW keeps INT/SQW driven on battery for the alarm interrupt as well as the
-// square wave (19-5170, Control Register and rev. 4), so arming an alarm must
-// leave it as found.
-using ds3231::alarm_interrupt;
-using ds3231::detail::control_with;
-static_assert(control_with(0x40, 0x01, alarm_interrupt::on) == 0x45);
-static_assert(control_with(0x00, 0x02, alarm_interrupt::on) == 0x06);
-static_assert(control_with(0x47, 0x01, alarm_interrupt::off) == 0x46);
-
-} // namespace
@@ -1,11 +0,0 @@
-#!/usr/bin/env bash
-# The task gate: every configure preset built, and only then every one tested.
-#
-# The loop itself is libavr's (tools/check-presets.sh): the mode-identity
-# checks read the sibling mode's tree, so a build-then-test-per-preset run
-# would compare a fresh image against a stale sibling. Anything this repository
-# needs beyond the presets is written after the call, where every tree is built
-# and tested.
-set -euo pipefail
-cd "$(dirname "${BASH_SOURCE[0]}")/.."
-"${LIBAVR_ROOT:-libavr}/tools/check-presets.sh" "$@"
Author	SHA1	Message	Date
BlackMark	2147637385	Update submodule	2020-05-17 20:11:51 +02:00
BlackMark	966af1d5cf	Add ability to read alarm times	2020-05-17 20:07:13 +02:00
BlackMark	a83671bda5	Add alarms to example	2020-05-17 19:56:11 +02:00
BlackMark	7e8a6b0dad	Add power control for RTC	2020-05-17 15:40:29 +02:00
BlackMark	a897b7d9be	Move comparison operator into library	2020-05-17 15:40:15 +02:00
BlackMark	f8ee536829	Only pass i2c backend to rtc class	2020-05-16 19:52:49 +02:00
BlackMark	2fd64c8611	Implement setting time through serial	2020-05-16 19:48:37 +02:00
BlackMark	97bb522189	Remove old rtc lib and systime	2020-05-16 19:20:32 +02:00
BlackMark	b8c7c9ec5c	Adapt to moved type submodule	2020-05-16 17:44:16 +02:00
BlackMark	5d77cad8d7	Add setting date-time example with new rtc lib	2020-05-16 17:26:56 +02:00
BlackMark	4b3dd99ebc	Add usage for new C++ driver	2020-05-15 19:48:22 +02:00
BlackMark	f00a154e59	Change i2c library	2020-05-15 11:51:51 +02:00
BlackMark	e9d3a95239	Move C time API glue from driver to user space	2020-05-15 10:21:34 +02:00
BlackMark	b2065b987a	Switch from old usart to new uart library	2020-05-15 09:43:06 +02:00
BlackMark	85e37de950	Ran clang-format	2020-05-15 09:29:26 +02:00
BlackMark	7310eb2c9a	Remove bootloader support	2020-05-15 09:28:05 +02:00
BlackMark	b02454c45b	Update submodule	2020-05-15 09:26:08 +02:00
BlackMark	af4f2ed0e5	Update project file to C++17 config with gcc 9	2020-05-15 09:24:24 +02:00
BlackMark	7a8d31718f	Add gitignore and clang-format file	2020-05-15 09:21:08 +02:00
BlackMark	05e8b1b53f	Change to 16 MHz crystal	2020-05-15 09:14:31 +02:00
BlackMark	a340cb04d3	Actually use ds3231 submodule instead of duplicating code	2020-05-15 09:06:34 +02:00
BlackMark	4cffd8f56b	Fix submodule path	2020-05-15 09:01:11 +02:00
BlackMark	6072c34eef	Fixed setting time bug, because of uninitialized tm struct	2018-01-02 17:21:04 +01:00
BlackMark	4bc59d1a33	Changed wrong CPU FREQ define to central correct one	2017-12-17 10:53:38 +01:00