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Implemented basic library and test application

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This commit is contained in:
BlackMark 2017-04-27 00:05:38 +02:00
parent e9e2cf2e63
commit e639db5e5b
12 changed files with 1816 additions and 47 deletions
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3
.gitmodules vendored Normal file
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[submodule "ds3231/usart"]
path = ds3231/usart
url = git@blackmark.me:usart.git

56
ds3231/bootloader.h Normal file
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/*
* Copyright (c) by BlackMark 2016
* Date 09/09/2016
* Version 1.4
*/
#ifndef BOOTLOADER_H
#define BOOTLOADER_H
#include <avr/pgmspace.h>
#include <avr/interrupt.h>
#include <avr/wdt.h>
typedef void (*flash)() __attribute__ ((noreturn));
flash boot = reinterpret_cast<flash>( 0x0000 );
flash bootloader = reinterpret_cast<flash>( 0x7E00 / 2 );
inline bool checkBootloader()
{
if( pgm_read_byte( reinterpret_cast<uint16_t>( bootloader ) * 2 ) == 0xF8 )
{
return true;
}
return false;
}
inline void callBootloader()
{
if( checkBootloader() )
{
bootloader();
}
else
{
boot();
}
}
inline uint8_t handleReset()
{
wdt_reset();
uint8_t ui8MCUSR = MCUSR;
MCUSR &= ~( 1 << WDRF );
wdt_disable();
return ui8MCUSR;
}
inline void reset()
{
wdt_enable( WDTO_15MS );
while( true );
}
#endif

14
ds3231/clock.h Normal file
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/*
* Copyright (c) by BlackMark 2015
* Date 24/11/2015
* Version 1.1
*/
#ifndef CLOCK_H
#define CLOCK_H
#define F_CPU 16000000
#include <util/delay.h>
#endif

175
ds3231/ds3231.cppproj
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@ -28,15 +28,15 @@
<eraseonlaunchrule>0</eraseonlaunchrule>
<AsfFrameworkConfig>
<framework-data xmlns="">
<options />
<configurations />
<files />
<documentation help="" />
<offline-documentation help="" />
<dependencies>
<content-extension eid="atmel.asf" uuidref="Atmel.ASF" version="3.34.2" />
</dependencies>
</framework-data>
<options />
<configurations />
<files />
<documentation help="" />
<offline-documentation help="" />
<dependencies>
<content-extension eid="atmel.asf" uuidref="Atmel.ASF" version="3.34.2" />
</dependencies>
</framework-data>
</AsfFrameworkConfig>
<avrtool>com.atmel.avrdbg.tool.simulator</avrtool>
<avrtoolserialnumber />
@ -70,33 +70,57 @@
<PropertyGroup Condition=" '$(Configuration)' == 'Release' ">
<ToolchainSettings>
<AvrGccCpp>
<avrgcc.common.Device>-mmcu=atmega328p -B "%24(PackRepoDir)\atmel\ATmega_DFP\1.2.132\gcc\dev\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.directories.IncludePaths><ListValues><Value>%24(PackRepoDir)\atmel\ATmega_DFP\1.2.132\include</Value></ListValues></avrgcc.compiler.directories.IncludePaths>
<avrgcc.compiler.optimization.PackStructureMembers>True</avrgcc.compiler.optimization.PackStructureMembers>
<avrgcc.compiler.optimization.AllocateBytesNeededForEnum>True</avrgcc.compiler.optimization.AllocateBytesNeededForEnum>
<avrgcc.compiler.warnings.AllWarnings>True</avrgcc.compiler.warnings.AllWarnings>
<avrgcccpp.compiler.general.ChangeDefaultCharTypeUnsigned>True</avrgcccpp.compiler.general.ChangeDefaultCharTypeUnsigned>
<avrgcccpp.compiler.general.ChangeDefaultBitFieldUnsigned>True</avrgcccpp.compiler.general.ChangeDefaultBitFieldUnsigned>
<avrgcccpp.compiler.directories.IncludePaths><ListValues><Value>%24(PackRepoDir)\atmel\ATmega_DFP\1.2.132\include</Value></ListValues></avrgcccpp.compiler.directories.IncludePaths>
<avrgcccpp.compiler.optimization.PackStructureMembers>True</avrgcccpp.compiler.optimization.PackStructureMembers>
<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>-Wextra -std=c++11</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\1.2.132\include</Value></ListValues></avrgcccpp.assembler.general.IncludePaths>
<avrgcc.compiler.symbols.DefSymbols><ListValues><Value>NDEBUG</Value></ListValues></avrgcc.compiler.symbols.DefSymbols>
<avrgcc.compiler.optimization.level>Optimize for size (-Os)</avrgcc.compiler.optimization.level>
<avrgcccpp.compiler.symbols.DefSymbols><ListValues><Value>NDEBUG</Value></ListValues></avrgcccpp.compiler.symbols.DefSymbols>
<avrgcccpp.compiler.optimization.level>Optimize for size (-Os)</avrgcccpp.compiler.optimization.level>
</AvrGccCpp>
<avrgcc.common.Device>-mmcu=atmega328p -B "%24(PackRepoDir)\atmel\ATmega_DFP\1.2.132\gcc\dev\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.directories.IncludePaths>
<ListValues>
<Value>%24(PackRepoDir)\atmel\ATmega_DFP\1.2.132\include</Value>
</ListValues>
</avrgcc.compiler.directories.IncludePaths>
<avrgcc.compiler.optimization.PackStructureMembers>True</avrgcc.compiler.optimization.PackStructureMembers>
<avrgcc.compiler.optimization.AllocateBytesNeededForEnum>True</avrgcc.compiler.optimization.AllocateBytesNeededForEnum>
<avrgcc.compiler.warnings.AllWarnings>True</avrgcc.compiler.warnings.AllWarnings>
<avrgcccpp.compiler.general.ChangeDefaultCharTypeUnsigned>True</avrgcccpp.compiler.general.ChangeDefaultCharTypeUnsigned>
<avrgcccpp.compiler.general.ChangeDefaultBitFieldUnsigned>True</avrgcccpp.compiler.general.ChangeDefaultBitFieldUnsigned>
<avrgcccpp.compiler.directories.IncludePaths>
<ListValues>
<Value>%24(PackRepoDir)\atmel\ATmega_DFP\1.2.132\include</Value>
</ListValues>
</avrgcccpp.compiler.directories.IncludePaths>
<avrgcccpp.compiler.optimization.PackStructureMembers>True</avrgcccpp.compiler.optimization.PackStructureMembers>
<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>-Wextra -std=c++11</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\1.2.132\include</Value>
</ListValues>
</avrgcccpp.assembler.general.IncludePaths>
<avrgcc.compiler.symbols.DefSymbols>
<ListValues>
<Value>NDEBUG</Value>
</ListValues>
</avrgcc.compiler.symbols.DefSymbols>
<avrgcc.compiler.optimization.level>Optimize for size (-Os)</avrgcc.compiler.optimization.level>
<avrgcccpp.compiler.symbols.DefSymbols>
<ListValues>
<Value>NDEBUG</Value>
</ListValues>
</avrgcccpp.compiler.symbols.DefSymbols>
<avrgcccpp.compiler.optimization.level>Optimize for size (-Os)</avrgcccpp.compiler.optimization.level>
</AvrGccCpp>
</ToolchainSettings>
<PreBuildEvent>echo "C:\avrdude-6.2\avrdude.exe" -v -p$(avrdevice) %%* -Uflash:w:"$(OutputDirectory)\$(Name).hex":i &gt; "$(MSBuildProjectDirectory)\avrdude.bat"</PreBuildEvent>
</PropertyGroup>
@ -111,35 +135,92 @@
<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.directories.IncludePaths><ListValues><Value>%24(PackRepoDir)\atmel\ATmega_DFP\1.2.132\include</Value></ListValues></avrgcc.compiler.directories.IncludePaths>
<avrgcc.compiler.symbols.DefSymbols>
<ListValues>
<Value>DEBUG</Value>
</ListValues>
</avrgcc.compiler.symbols.DefSymbols>
<avrgcc.compiler.directories.IncludePaths>
<ListValues>
<Value>%24(PackRepoDir)\atmel\ATmega_DFP\1.2.132\include</Value>
</ListValues>
</avrgcc.compiler.directories.IncludePaths>
<avrgcc.compiler.optimization.level>Optimize (-O1)</avrgcc.compiler.optimization.level>
<avrgcc.compiler.optimization.PackStructureMembers>True</avrgcc.compiler.optimization.PackStructureMembers>
<avrgcc.compiler.optimization.AllocateBytesNeededForEnum>True</avrgcc.compiler.optimization.AllocateBytesNeededForEnum>
<avrgcc.compiler.optimization.DebugLevel>Default (-g2)</avrgcc.compiler.optimization.DebugLevel>
<avrgcc.compiler.warnings.AllWarnings>True</avrgcc.compiler.warnings.AllWarnings>
<avrgcccpp.compiler.general.ChangeDefaultCharTypeUnsigned>True</avrgcccpp.compiler.general.ChangeDefaultCharTypeUnsigned>
<avrgcccpp.compiler.general.ChangeDefaultBitFieldUnsigned>True</avrgcccpp.compiler.general.ChangeDefaultBitFieldUnsigned>
<avrgcccpp.compiler.directories.IncludePaths><ListValues><Value>%24(PackRepoDir)\atmel\ATmega_DFP\1.2.132\include</Value></ListValues></avrgcccpp.compiler.directories.IncludePaths>
<avrgcccpp.compiler.symbols.DefSymbols>
<ListValues>
<Value>DEBUG</Value>
</ListValues>
</avrgcccpp.compiler.symbols.DefSymbols>
<avrgcccpp.compiler.directories.IncludePaths>
<ListValues>
<Value>%24(PackRepoDir)\atmel\ATmega_DFP\1.2.132\include</Value>
</ListValues>
</avrgcccpp.compiler.directories.IncludePaths>
<avrgcccpp.compiler.optimization.level>Optimize (-O1)</avrgcccpp.compiler.optimization.level>
<avrgcccpp.compiler.optimization.PackStructureMembers>True</avrgcccpp.compiler.optimization.PackStructureMembers>
<avrgcccpp.compiler.optimization.AllocateBytesNeededForEnum>True</avrgcccpp.compiler.optimization.AllocateBytesNeededForEnum>
<avrgcccpp.compiler.optimization.DebugLevel>Default (-g2)</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>-Wextra -std=c++11</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\1.2.132\include</Value></ListValues></avrgcccpp.assembler.general.IncludePaths>
<avrgcc.compiler.symbols.DefSymbols><ListValues><Value>DEBUG</Value></ListValues></avrgcc.compiler.symbols.DefSymbols>
<avrgcc.compiler.optimization.level>Optimize (-O1)</avrgcc.compiler.optimization.level>
<avrgcc.compiler.optimization.DebugLevel>Default (-g2)</avrgcc.compiler.optimization.DebugLevel>
<avrgcccpp.compiler.symbols.DefSymbols><ListValues><Value>DEBUG</Value></ListValues></avrgcccpp.compiler.symbols.DefSymbols>
<avrgcccpp.compiler.optimization.level>Optimize (-O1)</avrgcccpp.compiler.optimization.level>
<avrgcccpp.compiler.optimization.DebugLevel>Default (-g2)</avrgcccpp.compiler.optimization.DebugLevel>
<avrgcccpp.compiler.miscellaneous.OtherFlags>-Wextra -std=c++14</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\1.2.132\include</Value>
</ListValues>
</avrgcccpp.assembler.general.IncludePaths>
<avrgcccpp.assembler.debugging.DebugLevel>Default (-Wa,-g)</avrgcccpp.assembler.debugging.DebugLevel>
</AvrGccCpp>
</ToolchainSettings>
<PreBuildEvent>echo "C:\avrdude-6.2\avrdude.exe" -v -p$(avrdevice) %%* -Uflash:w:"$(OutputDirectory)\$(Name).hex":i &gt; "$(MSBuildProjectDirectory)\avrdude.bat"</PreBuildEvent>
</PropertyGroup>
<ItemGroup>
<Compile Include="bootloader.h">
<SubType>compile</SubType>
</Compile>
<Compile Include="clock.h">
<SubType>compile</SubType>
</Compile>
<Compile Include="main.cpp">
<SubType>compile</SubType>
</Compile>
<Compile Include="rtc.cpp">
<SubType>compile</SubType>
</Compile>
<Compile Include="rtc.h">
<SubType>compile</SubType>
</Compile>
<Compile Include="twi-lowlevel.cpp">
<SubType>compile</SubType>
</Compile>
<Compile Include="twi-lowlevel.h">
<SubType>compile</SubType>
</Compile>
<Compile Include="twi.cpp">
<SubType>compile</SubType>
</Compile>
<Compile Include="twi.h">
<SubType>compile</SubType>
</Compile>
<Compile Include="usart\usart.cpp">
<SubType>compile</SubType>
</Compile>
<Compile Include="usart\usart.h">
<SubType>compile</SubType>
</Compile>
</ItemGroup>
<ItemGroup>
<Folder Include="usart" />
</ItemGroup>
<Import Project="$(AVRSTUDIO_EXE_PATH)\\Vs\\Compiler.targets" />
</Project>

100
ds3231/main.cpp
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/*
* Copyright (c) by BlackMark 2017
* Date 26/04/2017
* Version 1.0
*/
#include <stdio.h>
#include "usart/usart.h"
#include "clock.h"
#include "bootloader.h"
#include "twi.h"
#include "rtc.h"
void setup()
{
USART0 &cSerial = USART0::inst();
twi_init_master();
rtc_init();
rtc_set_time_s( 12, 0, 50 );
if( rtc_is_ds3231() )
{
cSerial << "DS3231 detected!" << "\r\n";
}
else
{
cSerial << "ERROR - No RTC detected!" << "\r\n";
}
rtc_set_alarm_s( 12, 1, 0 );
}
int main()
{
uint8_t ui8MCUSR = handleReset();
if( ui8MCUSR & ( 1 << WDRF ) )
{
callBootloader();
}
USART0 &cSerial = USART0::inst();
cSerial.init( 9600 );
sei();
setup();
uint8_t ui8Hour;
uint8_t ui8Minute;
uint8_t ui8Second;
rtc_get_alarm_s( &ui8Hour, &ui8Minute, &ui8Second );
char szBuffer[32];
sprintf( szBuffer, "Alarm set to: %02d:%02d:%02d\r\n", ui8Hour, ui8Minute, ui8Second );
cSerial << szBuffer << "\r\n";
while( true )
{
tm* tmTime = rtc_get_time();
if( tmTime->sec != ui8Second )
{
ui8Hour = tmTime->hour;
ui8Minute = tmTime->min;
ui8Second = tmTime->sec;
sprintf( szBuffer, "%02d:%02d:%02d\r\n", ui8Hour, ui8Minute, ui8Second );
cSerial << "Time: " << szBuffer;
if( rtc_check_alarm() )
{
cSerial << "ALARM!" << "\r\n";
}
}
uint8_t ui8Bootloader;
if( cSerial.receiveByte( ui8Bootloader ) )
{
if( ui8Bootloader == 'b' )
{
cSerial << "Bootloader . . . " << "\r\n";
_delay_ms( 1000 );
reset();
}
else
{
cSerial << "Invalid char: '";
cSerial.transmitByte( ui8Bootloader );
cSerial << "'" << "\r\n";
}
}
}
return 0;
}

608
ds3231/rtc.cpp Normal file
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/*
* DS RTC Library: DS1307 and DS3231 driver library
* (C) 2011 Akafugu Corporation
*
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option) any later
* version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU General Public License for more details.
*
*/
/*
* DS1307 register map
*
* 00h-06h: seconds, minutes, hours, day-of-week, date, month, year (all in BCD)
* bit 7 of seconds enables/disables clock
* bit 6 of hours toggles 12/24h mode (1 for 12h, 0 for 24h)
* when 12h mode is selected bit 5 is high for PM, low for AM
* 07h: control
* bit7: OUT
* bit6: 0
* bit5: 0
* bit4: SQWE
* bit3: 0
* bit2: 0
* bit1: RS0
* bit0: RS1
* 08h-3fh: 56 bytes of SRAM
*
* DS3231 register map
*
* 00h-06h: seconds, minutes, hours, day-of-week, date, month, year (all in BCD)
* bit 7 should be set to zero: The DS3231 clock is always running
* 07h: A1M1 Alarm 1 seconds
* 08h: A1M2 Alarm 1 minutes
* 09h: A1M3 Alarm 1 hour (bit6 is am/pm flag in 12h mode)
* 0ah: A1M4 Alarm 1 day/date (bit6: 1 for day, 0 for date)
* 0bh: A2M2 Alarm 2 minutes
* 0ch: A2M3 Alarm 2 hour (bit6 is am/pm flag in 12h mode)
* 0dh: A2M4 Alarm 2 day/data (bit6: 1 for day, 0 for date)
* <see data sheet page12 for Alarm register mask bit tables:
* for alarm when hours, minutes and seconds match set 1000 for alarm 1>
* 0eh: control
* bit7: !EOSC
* bit6: BBSQW
* bit5: CONV
* bit4: RS2
* bit3: RS1
* bit2: INTCN
* bit1: A2IE
* bit0: A1IE
* 0fh: control/status
* bit7: OSF
* bit6: 0
* bit5: 0
* bit4: 0
* bit3: EN32kHz
* bit2: BSY
* bit1: A2F alarm 2 flag
* bit0: A1F alarm 1 flag
* 10h: aging offset (signed)
* 11h: MSB of temp (signed)
* 12h: LSB of temp in bits 7 and 6 (0.25 degrees for each 00, 01, 10, 11)
*
*/
#include <avr/io.h>
#define TRUE 1
#define FALSE 0
#include "rtc.h"
#define RTC_ADDR 0x68 // I2C address
#define CH_BIT 7 // clock halt bit
// statically allocated structure for time value
struct tm _tm;
uint8_t dec2bcd(uint8_t d)
{
return ((d/10 * 16) + (d % 10));
}
uint8_t bcd2dec(uint8_t b)
{
return ((b/16 * 10) + (b % 16));
}
uint8_t rtc_read_byte(uint8_t offset)
{
twi_begin_transmission(RTC_ADDR);
twi_send_byte(offset);
twi_end_transmission();
twi_request_from(RTC_ADDR, 1);
return twi_receive();
}
void rtc_write_byte(uint8_t b, uint8_t offset)
{
twi_begin_transmission(RTC_ADDR);
twi_send_byte(offset);
twi_send_byte(b);
twi_end_transmission();
}
static bool s_is_ds1307 = false;
static bool s_is_ds3231 = false;
void rtc_init(void)
{
// Attempt autodetection:
// 1) Read and save temperature register
// 2) Write a value to temperature register
// 3) Read back the value
// equal to the one written: DS1307, write back saved value and return
// different from written: DS3231
uint8_t temp1 = rtc_read_byte(0x11);
uint8_t temp2 = rtc_read_byte(0x12);
rtc_write_byte(0xee, 0x11);
rtc_write_byte(0xdd, 0x12);
if (rtc_read_byte(0x11) == 0xee && rtc_read_byte(0x12) == 0xdd) {
s_is_ds1307 = true;
// restore values
rtc_write_byte(temp1, 0x11);
rtc_write_byte(temp2, 0x12);
}
else {
s_is_ds3231 = true;
}
}
// Autodetection
bool rtc_is_ds1307(void) { return s_is_ds1307; }
bool rtc_is_ds3231(void) { return s_is_ds3231; }
// Autodetection override
void rtc_set_ds1307(void) { s_is_ds1307 = true; s_is_ds3231 = false; }
void rtc_set_ds3231(void) { s_is_ds1307 = false; s_is_ds3231 = true; }
struct tm* rtc_get_time(void)
{
uint8_t rtc[9];
uint8_t century = 0;
// read 7 bytes starting from register 0
// sec, min, hour, day-of-week, date, month, year
twi_begin_transmission(RTC_ADDR);
twi_send_byte(0x0);
twi_end_transmission();
twi_request_from(RTC_ADDR, 7);
for (uint8_t i = 0; i < 7; i++) {
rtc[i] = twi_receive();
}
twi_end_transmission();
// Clear clock halt bit from read data
// This starts the clock for a DS1307, and has no effect for a DS3231
rtc[0] &= ~(_BV(CH_BIT)); // clear bit
_tm.sec = bcd2dec(rtc[0]);
_tm.min = bcd2dec(rtc[1]);
_tm.hour = bcd2dec(rtc[2]);
_tm.mday = bcd2dec(rtc[4]);
_tm.mon = bcd2dec(rtc[5] & 0x1F); // returns 1-12
century = (rtc[5] & 0x80) >> 7;
_tm.year = century == 1 ? 2000 + bcd2dec(rtc[6]) : 1900 + bcd2dec(rtc[6]); // year 0-99
_tm.wday = bcd2dec(rtc[3]); // returns 1-7
if (_tm.hour == 0) {
_tm.twelveHour = 0;
_tm.am = 1;
} else if (_tm.hour < 12) {
_tm.twelveHour = _tm.hour;
_tm.am = 1;
} else {
_tm.twelveHour = _tm.hour - 12;
_tm.am = 0;
}
return &_tm;
}
void rtc_get_time_s(uint8_t* hour, uint8_t* min, uint8_t* sec)
{
uint8_t rtc[9];
// read 7 bytes starting from register 0
// sec, min, hour, day-of-week, date, month, year
twi_begin_transmission(RTC_ADDR);
twi_send_byte(0x0);
twi_end_transmission();
twi_request_from(RTC_ADDR, 7);
for(uint8_t i=0; i<7; i++) {
rtc[i] = twi_receive();
}
twi_end_transmission();
if (sec) *sec = bcd2dec(rtc[0]);
if (min) *min = bcd2dec(rtc[1]);
if (hour) *hour = bcd2dec(rtc[2]);
}
// fixme: support 12-hour mode for setting time
void rtc_set_time(struct tm* tm_)
{
twi_begin_transmission(RTC_ADDR);
twi_send_byte(0x0);
uint8_t century;
if (tm_->year > 2000) {
century = 0x80;
tm_->year = tm_->year - 2000;
} else {
century = 0;
tm_->year = tm_->year - 1900;
}
// clock halt bit is 7th bit of seconds: this is always cleared to start the clock
twi_send_byte(dec2bcd(tm_->sec)); // seconds
twi_send_byte(dec2bcd(tm_->min)); // minutes
twi_send_byte(dec2bcd(tm_->hour)); // hours
twi_send_byte(dec2bcd(tm_->wday)); // day of week
twi_send_byte(dec2bcd(tm_->mday)); // day
twi_send_byte(dec2bcd(tm_->mon) + century); // month
twi_send_byte(dec2bcd(tm_->year)); // year
twi_end_transmission();
}
void rtc_set_time_s(uint8_t hour, uint8_t min, uint8_t sec)
{
twi_begin_transmission(RTC_ADDR);
twi_send_byte(0x0);
// clock halt bit is 7th bit of seconds: this is always cleared to start the clock
twi_send_byte(dec2bcd(sec)); // seconds
twi_send_byte(dec2bcd(min)); // minutes
twi_send_byte(dec2bcd(hour)); // hours
twi_end_transmission();
}
// DS1307 only (has no effect when run on DS3231)
// halt/start the clock
// 7th bit of register 0 (second register)
// 0 = clock is running
// 1 = clock is not running
void rtc_run_clock(bool run)
{
if (s_is_ds3231) return;
uint8_t b = rtc_read_byte(0x0);
if (run)
b &= ~(_BV(CH_BIT)); // clear bit
else
b |= _BV(CH_BIT); // set bit
rtc_write_byte(b, 0x0);
}
// DS1307 only
// Returns true if the clock is running, false otherwise
// For DS3231, it always returns true
bool rtc_is_clock_running(void)
{
if (s_is_ds3231) return true;
uint8_t b = rtc_read_byte(0x0);
if (b & _BV(CH_BIT)) return false;
return true;
}
void ds3231_get_temp_int(int8_t* i, uint8_t* f)
{
uint8_t msb, lsb;
*i = 0;
*f = 0;
if (s_is_ds1307) return; // only valid on DS3231
twi_begin_transmission(RTC_ADDR);
// temp registers 0x11 and 0x12
twi_send_byte(0x11);
twi_end_transmission();
twi_request_from(RTC_ADDR, 2);
if (twi_available()) {
msb = twi_receive(); // integer part (in twos complement)
lsb = twi_receive(); // fraction part
// integer part in entire byte
*i = msb;
// fractional part in top two bits (increments of 0.25)
*f = (lsb >> 6) * 25;
// float value can be read like so:
// float temp = ((((short)msb << 8) | (short)lsb) >> 6) / 4.0f;
}
}
void rtc_force_temp_conversion(uint8_t block)
{
if (s_is_ds1307) return; // only valid on DS3231
// read control register (0x0E)
twi_begin_transmission(RTC_ADDR);
twi_send_byte(0x0E);
twi_end_transmission();
twi_request_from(RTC_ADDR, 1);
uint8_t ctrl = twi_receive();
ctrl |= 0b00100000; // Set CONV bit
// write new control register value
twi_begin_transmission(RTC_ADDR);
twi_send_byte(0x0E);
twi_send_byte(ctrl);
twi_end_transmission();
if (!block) return;
// Temp conversion is ready when control register becomes 0
do {
// Block until CONV is 0
twi_begin_transmission(RTC_ADDR);
twi_send_byte(0x0E);
twi_end_transmission();
twi_request_from(RTC_ADDR, 1);
} while ((twi_receive() & 0b00100000) != 0);
}
#define DS1307_SRAM_ADDR 0x08
// SRAM: 56 bytes from address 0x08 to 0x3f (DS1307-only)
void rtc_get_sram(uint8_t* data)
{
// cannot receive 56 bytes in one go, because of the TWI library buffer limit
// so just receive one at a time for simplicity
for(int i=0;i<56;i++)
data[i] = rtc_get_sram_byte(i);
}
void rtc_set_sram(uint8_t *data)
{
// cannot send 56 bytes in one go, because of the TWI library buffer limit
// so just send one at a time for simplicity
for(int i=0;i<56;i++)
rtc_set_sram_byte(data[i], i);
}
uint8_t rtc_get_sram_byte(uint8_t offset)
{
twi_begin_transmission(RTC_ADDR);
twi_send_byte(DS1307_SRAM_ADDR + offset);
twi_end_transmission();
twi_request_from(RTC_ADDR, 1);
return twi_receive();
}
void rtc_set_sram_byte(uint8_t b, uint8_t offset)
{
twi_begin_transmission(RTC_ADDR);
twi_send_byte(DS1307_SRAM_ADDR + offset);
twi_send_byte(b);
twi_end_transmission();
}
void rtc_SQW_enable(bool enable)
{
if (s_is_ds1307) {
twi_begin_transmission(RTC_ADDR);
twi_send_byte(0x07);
twi_end_transmission();
// read control
twi_request_from(RTC_ADDR, 1);
uint8_t control = twi_receive();
if (enable)
control |= 0b00010000; // set SQWE to 1
else
control &= ~0b00010000; // set SQWE to 0
// write control back
twi_begin_transmission(RTC_ADDR);
twi_send_byte(0x07);
twi_send_byte(control);
twi_end_transmission();
}
else { // DS3231
twi_begin_transmission(RTC_ADDR);
twi_send_byte(0x0E);
twi_end_transmission();
// read control
twi_request_from(RTC_ADDR, 1);
uint8_t control = twi_receive();
if (enable) {
control |= 0b01000000; // set BBSQW to 1
control &= ~0b00000100; // set INTCN to 0
}
else {
control &= ~0b01000000; // set BBSQW to 0
}
// write control back
twi_begin_transmission(RTC_ADDR);
twi_send_byte(0x0E);
twi_send_byte(control);
twi_end_transmission();
}
}
void rtc_SQW_set_freq(enum RTC_SQW_FREQ freq)
{
if (s_is_ds1307) {
twi_begin_transmission(RTC_ADDR);
twi_send_byte(0x07);
twi_end_transmission();
// read control (uses bits 0 and 1)
twi_request_from(RTC_ADDR, 1);
uint8_t control = twi_receive();
control &= ~0b00000011; // Set to 0
control |= freq; // Set freq bitmask
// write control back
twi_begin_transmission(RTC_ADDR);
twi_send_byte(0x07);
twi_send_byte(control);
twi_end_transmission();
}
else { // DS3231
twi_begin_transmission(RTC_ADDR);
twi_send_byte(0x0E);
twi_end_transmission();
// read control (uses bits 3 and 4)
twi_request_from(RTC_ADDR, 1);
uint8_t control = twi_receive();
control &= ~0b00011000; // Set to 0
control |= (freq << 4); // Set freq bitmask
// write control back
twi_begin_transmission(RTC_ADDR);
twi_send_byte(0x0E);
twi_send_byte(control);
twi_end_transmission();
}
}
void rtc_osc32kHz_enable(bool enable)
{
if (!s_is_ds3231) return;
twi_begin_transmission(RTC_ADDR);
twi_send_byte(0x0F);
twi_end_transmission();
// read status
twi_request_from(RTC_ADDR, 1);
uint8_t status = twi_receive();
if (enable)
status |= 0b00001000; // set to 1
else
status &= ~0b00001000; // Set to 0
// write status back
twi_begin_transmission(RTC_ADDR);
twi_send_byte(0x0F);
twi_send_byte(status);
twi_end_transmission();
}
// Alarm functionality
// fixme: should decide if "alarm disabled" mode should be available, or if alarm should always be enabled
// at 00:00:00. Currently, "alarm disabled" only works for ds3231
void rtc_reset_alarm(void)
{
if (s_is_ds1307) {
rtc_set_sram_byte(0, 0); // hour
rtc_set_sram_byte(0, 1); // minute
rtc_set_sram_byte(0, 2); // second
}
else {
// writing 0 to bit 7 of all four alarm 1 registers disables alarm
rtc_write_byte(0, 0x07); // second
rtc_write_byte(0, 0x08); // minute
rtc_write_byte(0, 0x09); // hour
rtc_write_byte(0, 0x0a); // day
}
}
// fixme: add an option to set whether or not the INTCN and Interrupt Enable flag is set when setting the alarm
void rtc_set_alarm_s(uint8_t hour, uint8_t min, uint8_t sec)
{
if (hour > 23) return;
if (min > 59) return;
if (sec > 59) return;
if (s_is_ds1307) {
rtc_set_sram_byte(hour, 0); // hour
rtc_set_sram_byte(min, 1); // minute
rtc_set_sram_byte(sec, 2); // second
}
else {
/*
* 07h: A1M1:0 Alarm 1 seconds
* 08h: A1M2:0 Alarm 1 minutes
* 09h: A1M3:0 Alarm 1 hour (bit6 is am/pm flag in 12h mode)
* 0ah: A1M4:1 Alarm 1 day/date (bit6: 1 for day, 0 for date)
* Sets alarm to fire when hour, minute and second matches
*/
rtc_write_byte(dec2bcd(sec), 0x07); // second
rtc_write_byte(dec2bcd(min), 0x08); // minute
rtc_write_byte(dec2bcd(hour), 0x09); // hour
rtc_write_byte(0b10000001, 0x0a); // day (upper bit must be set)
// clear alarm flag
uint8_t val = rtc_read_byte(0x0f);
rtc_write_byte(val & ~0b00000001, 0x0f);
}
}
void rtc_set_alarm(struct tm* tm_)
{
if (!tm_) return;
rtc_set_alarm_s(tm_->hour, tm_->min, tm_->sec);
}
void rtc_get_alarm_s(uint8_t* hour, uint8_t* min, uint8_t* sec)
{
if (s_is_ds1307) {
if (hour) *hour = rtc_get_sram_byte(0);
if (min) *min = rtc_get_sram_byte(1);
if (sec) *sec = rtc_get_sram_byte(2);
}
else {
*sec = bcd2dec(rtc_read_byte(0x07) & ~0b10000000);
*min = bcd2dec(rtc_read_byte(0x08) & ~0b10000000);
*hour = bcd2dec(rtc_read_byte(0x09) & ~0b10000000);
}
}
struct tm* rtc_get_alarm(void)
{
uint8_t hour, min, sec;
rtc_get_alarm_s(&hour, &min, &sec);
_tm.hour = hour;
_tm.min = min;
_tm.sec = sec;
return &_tm;
}
bool rtc_check_alarm(void)
{
if (s_is_ds1307) {
uint8_t hour = rtc_get_sram_byte(0);
uint8_t min = rtc_get_sram_byte(1);
uint8_t sec = rtc_get_sram_byte(2);
uint8_t cur_hour, cur_min, cur_sec;
rtc_get_time_s(&cur_hour, &cur_min, &cur_sec);
if (cur_hour == hour && cur_min == min && cur_sec == sec)
return true;
return false;
}
else {
// Alarm 1 flag (A1F) in bit 0
uint8_t val = rtc_read_byte(0x0f);
// clear flag when set
if (val & 1)
rtc_write_byte(val & ~0b00000001, 0x0f);
return val & 1 ? 1 : 0;
}
}

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/*
* DS RTC Library: DS1307 and DS3231 driver library
* (C) 2011 Akafugu Corporation
*
* This program is free software; you can redistribute it and/or modify it under the
* terms of the GNU General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option) any later
* version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
* PARTICULAR PURPOSE. See the GNU General Public License for more details.
*
*/
#ifndef DS1307_H
#define DS1307_H
#include <stdbool.h>
#include <avr/io.h>
#include "twi.h"
#define DS1307_SLAVE_ADDR 0b11010000
/** Time structure
*
* Both 24-hour and 12-hour time is stored, and is always updated when rtc_get_time is called.
*
* When setting time and alarm, 24-hour mode is always used.
*
* If you run your clock in 12-hour mode:
* - set time hour to store in twelveHour and set am to true or false.
* - call rtc_12h_translate (this will put the correct value in hour, so you don't have to
* calculate it yourself.
* - call rtc_set_alarm or rtc_set_clock
*
* Note that rtc_set_clock_s, rtc_set_alarm_s, rtc_get_time_s, rtc_set_alarm_s always operate in 24-hour mode
* and translation has to be done manually (you can call rtc_24h_to_12h to perform the calculation)
*
*/
struct tm {
int sec; // 0 to 59
int min; // 0 to 59
int hour; // 0 to 23
int mday; // 1 to 31
int mon; // 1 to 12
int year; // year-99
int wday; // 1-7
// 12-hour clock data
bool am; // true for AM, false for PM
int twelveHour; // 12 hour clock time
};
// statically allocated
extern struct tm _tm;
// Initialize the RTC and autodetect type (DS1307 or DS3231)
void rtc_init(void);
// Autodetection
bool rtc_is_ds1307(void);
bool rtc_is_ds3231(void);
void rtc_set_ds1307(void);
void rtc_set_ds3231(void);
// Get/set time
// Gets the time: Supports both 24-hour and 12-hour mode
struct tm* rtc_get_time(void);
// Gets the time: 24-hour mode only
void rtc_get_time_s(uint8_t* hour, uint8_t* min, uint8_t* sec);
// Sets the time: Supports both 24-hour and 12-hour mode
void rtc_set_time(struct tm* tm_);
// Sets the time: Supports 12-hour mode only
void rtc_set_time_s(uint8_t hour, uint8_t min, uint8_t sec);
// start/stop clock running (DS1307 only)
void rtc_run_clock(bool run);
bool rtc_is_clock_running(void);
// Read Temperature (DS3231 only)
void ds3231_get_temp_int(int8_t* i, uint8_t* f);
void rtc_force_temp_conversion(uint8_t block);
// SRAM read/write DS1307 only
void rtc_get_sram(uint8_t* data);
void rtc_set_sram(uint8_t *data);
uint8_t rtc_get_sram_byte(uint8_t offset);
void rtc_set_sram_byte(uint8_t b, uint8_t offset);
// Auxillary functions
enum RTC_SQW_FREQ { FREQ_1 = 0, FREQ_1024, FREQ_4096, FREQ_8192 };
void rtc_SQW_enable(bool enable);
void rtc_SQW_set_freq(enum RTC_SQW_FREQ freq);
void rtc_osc32kHz_enable(bool enable);
// Alarm functionality
void rtc_reset_alarm(void);
void rtc_set_alarm(struct tm* tm_);
void rtc_set_alarm_s(uint8_t hour, uint8_t min, uint8_t sec);
struct tm* rtc_get_alarm(void);
void rtc_get_alarm_s(uint8_t* hour, uint8_t* min, uint8_t* sec);
bool rtc_check_alarm(void);
#endif

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/*
twi.c - TWI/I2C library for Wiring & Arduino
Copyright (c) 2006 Nicholas Zambetti. All right reserved.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <math.h>
#include <stdlib.h>
#include <inttypes.h>
#include <avr/io.h>
#include <avr/interrupt.h>
#include <compat/twi.h>
#ifndef cbi
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#endif
#ifndef sbi
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
#endif
#include "twi-lowlevel.h"
static volatile uint8_t twi_state;
static uint8_t twi_slarw;
static void (*twi_onSlaveTransmit)(void);
static void (*twi_onSlaveReceive)(uint8_t*, int);
static uint8_t twi_masterBuffer[TWI_BUFFER_LENGTH];
static volatile uint8_t twi_masterBufferIndex;
static uint8_t twi_masterBufferLength;
static uint8_t twi_txBuffer[TWI_BUFFER_LENGTH];
static volatile uint8_t twi_txBufferIndex;
static volatile uint8_t twi_txBufferLength;
static uint8_t twi_rxBuffer[TWI_BUFFER_LENGTH];
static volatile uint8_t twi_rxBufferIndex;
static volatile uint8_t twi_error;
/*
* Function twi_init
* Desc readys twi pins and sets twi bitrate
* Input none
* Output none
*/
void twi_init(void)
{
// initialize state
twi_state = TWI_READY;
#if defined(__AVR_ATmega168__) || defined(__AVR_ATmega8__) || defined(__AVR_ATmega328P__)
// activate internal pull-ups for twi
// as per note from atmega8 manual pg167
sbi(PORTC, 4);
sbi(PORTC, 5);
#else
// activate internal pull-ups for twi
// as per note from atmega128 manual pg204
sbi(PORTD, 0);
sbi(PORTD, 1);
#endif
// initialize twi prescaler and bit rate
cbi(TWSR, TWPS0);
cbi(TWSR, TWPS1);
TWBR = ((CPU_FREQ / TWI_FREQ) - 16) / 2;
/* twi bit rate formula from atmega128 manual pg 204
SCL Frequency = CPU Clock Frequency / (16 + (2 * TWBR))
note: TWBR should be 10 or higher for master mode
It is 72 for a 16mhz Wiring board with 100kHz TWI */
// enable twi module, acks, and twi interrupt
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA);
}
/*
* Function twi_slaveInit
* Desc sets slave address and enables interrupt
* Input none
* Output none
*/
void twi_setAddress(uint8_t address)
{
// set twi slave address (skip over TWGCE bit)
TWAR = address << 1;
}
/*
* Function twi_readFrom
* Desc attempts to become twi bus master and read a
* series of bytes from a device on the bus
* Input address: 7bit i2c device address
* data: pointer to byte array
* length: number of bytes to read into array
* Output number of bytes read
*/
uint8_t twi_readFrom(uint8_t address, uint8_t* data, uint8_t length)
{
uint8_t i;
// ensure data will fit into buffer
if(TWI_BUFFER_LENGTH < length){
return 0;
}
// wait until twi is ready, become master receiver
while(TWI_READY != twi_state){
continue;
}
twi_state = TWI_MRX;
// reset error state (0xFF.. no error occured)
twi_error = 0xFF;
// initialize buffer iteration vars
twi_masterBufferIndex = 0;
twi_masterBufferLength = length-1; // This is not intuitive, read on...
// On receive, the previously configured ACK/NACK setting is transmitted in
// response to the received byte before the interrupt is signalled.
// Therefor we must actually set NACK when the _next_ to last byte is
// received, causing that NACK to be sent in response to receiving the last
// expected byte of data.
// build sla+w, slave device address + w bit
twi_slarw = TW_READ;
twi_slarw |= address << 1;
// send start condition
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT) | _BV(TWSTA);
// wait for read operation to complete
while(TWI_MRX == twi_state){
continue;
}
if (twi_masterBufferIndex < length)
length = twi_masterBufferIndex;
// copy twi buffer to data
for(i = 0; i < length; ++i){
data[i] = twi_masterBuffer[i];
}
return length;
}
/*
* Function twi_writeTo
* Desc attempts to become twi bus master and write a
* series of bytes to a device on the bus
* Input address: 7bit i2c device address
* data: pointer to byte array
* length: number of bytes in array
* wait: boolean indicating to wait for write or not
* Output 0 .. success
* 1 .. length to long for buffer
* 2 .. address send, NACK received
* 3 .. data send, NACK received
* 4 .. other twi error (lost bus arbitration, bus error, ..)
*/
uint8_t twi_writeTo(uint8_t address, uint8_t* data, uint8_t length, uint8_t wait)
{
uint8_t i;
// ensure data will fit into buffer
if(TWI_BUFFER_LENGTH < length){
return 1;
}
// wait until twi is ready, become master transmitter
while(TWI_READY != twi_state){
continue;
}
twi_state = TWI_MTX;
// reset error state (0xFF.. no error occured)
twi_error = 0xFF;
// initialize buffer iteration vars
twi_masterBufferIndex = 0;
twi_masterBufferLength = length;
// copy data to twi buffer
for(i = 0; i < length; ++i){
twi_masterBuffer[i] = data[i];
}
// build sla+w, slave device address + w bit
twi_slarw = TW_WRITE;
twi_slarw |= address << 1;
// send start condition
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT) | _BV(TWSTA);
// wait for write operation to complete
while(wait && (TWI_MTX == twi_state)){
continue;
}
if (twi_error == 0xFF)
return 0; // success
else if (twi_error == TW_MT_SLA_NACK)
return 2; // error: address send, nack received
else if (twi_error == TW_MT_DATA_NACK)
return 3; // error: data send, nack received
else
return 4; // other twi error
}
/*
* Function twi_transmit
* Desc fills slave tx buffer with data
* must be called in slave tx event callback
* Input data: pointer to byte array
* length: number of bytes in array
* Output 1 length too long for buffer
* 2 not slave transmitter
* 0 ok
*/
uint8_t twi_transmit(uint8_t* data, uint8_t length)
{
uint8_t i;
// ensure data will fit into buffer
if(TWI_BUFFER_LENGTH < length){
return 1;
}
// ensure we are currently a slave transmitter
if(TWI_STX != twi_state){
return 2;
}
// set length and copy data into tx buffer
twi_txBufferLength = length;
for(i = 0; i < length; ++i){
twi_txBuffer[i] = data[i];
}
return 0;
}
/*
* Function twi_attachSlaveRxEvent
* Desc sets function called before a slave read operation
* Input function: callback function to use
* Output none
*/
void twi_attachSlaveRxEvent( void (*function)(uint8_t*, int) )
{
twi_onSlaveReceive = function;
}
/*
* Function twi_attachSlaveTxEvent
* Desc sets function called before a slave write operation
* Input function: callback function to use
* Output none
*/
void twi_attachSlaveTxEvent( void (*function)(void) )
{
twi_onSlaveTransmit = function;
}
/*
* Function twi_reply
* Desc sends byte or readys receive line
* Input ack: byte indicating to ack or to nack
* Output none
*/
void twi_reply(uint8_t ack)
{
// transmit master read ready signal, with or without ack
if(ack){
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWINT) | _BV(TWEA);
}else{
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWINT);
}
}
/*
* Function twi_stop
* Desc relinquishes bus master status
* Input none
* Output none
*/
void twi_stop(void)
{
// send stop condition
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT) | _BV(TWSTO);
// wait for stop condition to be exectued on bus
// TWINT is not set after a stop condition!
while(TWCR & _BV(TWSTO)){
continue;
}
// update twi state
twi_state = TWI_READY;
}
/*
* Function twi_releaseBus
* Desc releases bus control
* Input none
* Output none
*/
void twi_releaseBus(void)
{
// release bus
TWCR = _BV(TWEN) | _BV(TWIE) | _BV(TWEA) | _BV(TWINT);
// update twi state
twi_state = TWI_READY;
}
SIGNAL(TWI_vect)
{
switch(TW_STATUS){
// All Master
case TW_START: // sent start condition
case TW_REP_START: // sent repeated start condition
// copy device address and r/w bit to output register and ack
TWDR = twi_slarw;
twi_reply(1);
break;
// Master Transmitter
case TW_MT_SLA_ACK: // slave receiver acked address
case TW_MT_DATA_ACK: // slave receiver acked data
// if there is data to send, send it, otherwise stop
if(twi_masterBufferIndex < twi_masterBufferLength){
// copy data to output register and ack
TWDR = twi_masterBuffer[twi_masterBufferIndex++];
twi_reply(1);
}else{
twi_stop();
}
break;
case TW_MT_SLA_NACK: // address sent, nack received
twi_error = TW_MT_SLA_NACK;
twi_stop();
break;
case TW_MT_DATA_NACK: // data sent, nack received
twi_error = TW_MT_DATA_NACK;
twi_stop();
break;
case TW_MT_ARB_LOST: // lost bus arbitration
twi_error = TW_MT_ARB_LOST;
twi_releaseBus();
break;
// Master Receiver
case TW_MR_DATA_ACK: // data received, ack sent
// put byte into buffer
twi_masterBuffer[twi_masterBufferIndex++] = TWDR;
case TW_MR_SLA_ACK: // address sent, ack received
// ack if more bytes are expected, otherwise nack
if(twi_masterBufferIndex < twi_masterBufferLength){
twi_reply(1);
}else{
twi_reply(0);
}
break;
case TW_MR_DATA_NACK: // data received, nack sent
// put final byte into buffer
twi_masterBuffer[twi_masterBufferIndex++] = TWDR;
case TW_MR_SLA_NACK: // address sent, nack received
twi_stop();
break;
// TW_MR_ARB_LOST handled by TW_MT_ARB_LOST case
// Slave Receiver
case TW_SR_SLA_ACK: // addressed, returned ack
case TW_SR_GCALL_ACK: // addressed generally, returned ack
case TW_SR_ARB_LOST_SLA_ACK: // lost arbitration, returned ack
case TW_SR_ARB_LOST_GCALL_ACK: // lost arbitration, returned ack
// enter slave receiver mode
twi_state = TWI_SRX;
// indicate that rx buffer can be overwritten and ack
twi_rxBufferIndex = 0;
twi_reply(1);
break;
case TW_SR_DATA_ACK: // data received, returned ack
case TW_SR_GCALL_DATA_ACK: // data received generally, returned ack
// if there is still room in the rx buffer
if(twi_rxBufferIndex < TWI_BUFFER_LENGTH){
// put byte in buffer and ack
twi_rxBuffer[twi_rxBufferIndex++] = TWDR;
twi_reply(1);
}else{
// otherwise nack
twi_reply(0);
}
break;
case TW_SR_STOP: // stop or repeated start condition received
// put a null char after data if there's room
if(twi_rxBufferIndex < TWI_BUFFER_LENGTH){
twi_rxBuffer[twi_rxBufferIndex] = '\0';
}
// sends ack and stops interface for clock stretching
twi_stop();
// callback to user defined callback
twi_onSlaveReceive(twi_rxBuffer, twi_rxBufferIndex);
// since we submit rx buffer to "wire" library, we can reset it
twi_rxBufferIndex = 0;
// ack future responses and leave slave receiver state
twi_releaseBus();
break;
case TW_SR_DATA_NACK: // data received, returned nack
case TW_SR_GCALL_DATA_NACK: // data received generally, returned nack
// nack back at master
twi_reply(0);
break;
// Slave Transmitter
case TW_ST_SLA_ACK: // addressed, returned ack
case TW_ST_ARB_LOST_SLA_ACK: // arbitration lost, returned ack
// enter slave transmitter mode
twi_state = TWI_STX;
// ready the tx buffer index for iteration
twi_txBufferIndex = 0;
// set tx buffer length to be zero, to verify if user changes it
twi_txBufferLength = 0;
// request for txBuffer to be filled and length to be set
// note: user must call twi_transmit(bytes, length) to do this
twi_onSlaveTransmit();
// if they didn't change buffer & length, initialize it
if(0 == twi_txBufferLength){
twi_txBufferLength = 1;
twi_txBuffer[0] = 0x00;
}
// transmit first byte from buffer, fall
case TW_ST_DATA_ACK: // byte sent, ack returned
// copy data to output register
TWDR = twi_txBuffer[twi_txBufferIndex++];
// if there is more to send, ack, otherwise nack
if(twi_txBufferIndex < twi_txBufferLength){
twi_reply(1);
}else{
twi_reply(0);
}
break;
case TW_ST_DATA_NACK: // received nack, we are done
case TW_ST_LAST_DATA: // received ack, but we are done already!
// ack future responses
twi_reply(1);
// leave slave receiver state
twi_state = TWI_READY;
break;
// All
case TW_NO_INFO: // no state information
break;
case TW_BUS_ERROR: // bus error, illegal stop/start
twi_error = TW_BUS_ERROR;
twi_stop();
break;
}
}

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/*
twi.h - TWI/I2C library for Wiring & Arduino
Copyright (c) 2006 Nicholas Zambetti. All right reserved.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef twi_h
#define twi_h
#include <inttypes.h>
//#define ATMEGA8
#ifndef CPU_FREQ
#define CPU_FREQ 16000000L
#endif
#ifndef TWI_FREQ
#define TWI_FREQ 100000L
#endif
#ifndef TWI_BUFFER_LENGTH
#define TWI_BUFFER_LENGTH 32
#endif
#define TWI_READY 0
#define TWI_MRX 1
#define TWI_MTX 2
#define TWI_SRX 3
#define TWI_STX 4
void twi_init(void);
void twi_setAddress(uint8_t);
uint8_t twi_readFrom(uint8_t, uint8_t*, uint8_t);
uint8_t twi_writeTo(uint8_t, uint8_t*, uint8_t, uint8_t);
uint8_t twi_transmit(uint8_t*, uint8_t);
void twi_attachSlaveRxEvent( void (*)(uint8_t*, int) );
void twi_attachSlaveTxEvent( void (*)(void) );
void twi_reply(uint8_t);
void twi_stop(void);
void twi_releaseBus(void);
#endif

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ds3231/twi.cpp Normal file
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/*
TwoWire.cpp - TWI/I2C library for Wiring & Arduino
Copyright (c) 2006 Nicholas Zambetti. All right reserved.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>
#include "twi-lowlevel.h"
#include "twi.h"
// local variables
uint8_t rxBuffer[BUFFER_LENGTH];
uint8_t rxBufferIndex = 0;
uint8_t rxBufferLength = 0;
uint8_t txAddress = 0;
uint8_t txBuffer[BUFFER_LENGTH];
uint8_t txBufferIndex = 0;
uint8_t txBufferLength = 0;
uint8_t transmitting = 0;
void (*user_onRequest)(void);
void (*user_onReceive)(int);
void onRequestService(void);
void onReceiveService(uint8_t*, int);
void twi_init_master(void)
{
rxBufferIndex = 0;
rxBufferLength = 0;
txBufferIndex = 0;
txBufferLength = 0;
twi_init();
}
void twi_init_slave(uint8_t address)
{
twi_setAddress(address);
twi_attachSlaveTxEvent(onRequestService);
twi_attachSlaveRxEvent(onReceiveService);
twi_init_master();
}
uint8_t twi_request_from(uint8_t address, uint8_t quantity)
{
// clamp to buffer length
if(quantity > BUFFER_LENGTH){
quantity = BUFFER_LENGTH;
}
// perform blocking read into buffer
uint8_t read = twi_readFrom(address, rxBuffer, quantity);
// set rx buffer iterator vars
rxBufferIndex = 0;
rxBufferLength = read;
return read;
}
void twi_begin_transmission(uint8_t address)
{
// indicate that we are transmitting
transmitting = 1;
// set address of targeted slave
txAddress = address;
// reset tx buffer iterator vars
txBufferIndex = 0;
txBufferLength = 0;
}
uint8_t twi_end_transmission(void)
{
// transmit buffer (blocking)
int8_t ret = twi_writeTo(txAddress, txBuffer, txBufferLength, 1);
// reset tx buffer iterator vars
txBufferIndex = 0;
txBufferLength = 0;
// indicate that we are done transmitting
transmitting = 0;
return ret;
}
// must be called in:
// slave tx event callback
// or after beginTransmission(address)
void twi_send_byte(uint8_t data)
{
if(transmitting){
// in master transmitter mode
// don't bother if buffer is full
if(txBufferLength >= BUFFER_LENGTH){
return;
}
// put byte in tx buffer
txBuffer[txBufferIndex] = data;
++txBufferIndex;
// update amount in buffer
txBufferLength = txBufferIndex;
}else{
// in slave send mode
// reply to master
twi_transmit(&data, 1);
}
}
// must be called in:
// slave tx event callback
// or after beginTransmission(address)
void twi_send(uint8_t* data, uint8_t quantity)
{
if(transmitting){
// in master transmitter mode
for(uint8_t i = 0; i < quantity; ++i){
twi_send_byte(data[i]);
}
}else{
// in slave send mode
// reply to master
twi_transmit(data, quantity);
}
}
// must be called in:
// slave tx event callback
// or after beginTransmission(address)
void twi_send_char(char* data)
{
twi_send((uint8_t*)data, strlen(data));
}
// must be called in:
// slave rx event callback
// or after requestFrom(address, numBytes)
uint8_t twi_available(void)
{
return rxBufferLength - rxBufferIndex;
}
// must be called in:
// slave rx event callback
// or after requestFrom(address, numBytes)
uint8_t twi_receive(void)
{
// default to returning null char
// for people using with char strings
uint8_t value = '\0';
// get each successive byte on each call
if(rxBufferIndex < rxBufferLength){
value = rxBuffer[rxBufferIndex];
++rxBufferIndex;
}
return value;
}
// behind the scenes function that is called when data is received
void onReceiveService(uint8_t* inBytes, int numBytes)
{
// don't bother if user hasn't registered a callback
if(!user_onReceive){
return;
}
// don't bother if rx buffer is in use by a master requestFrom() op
// i know this drops data, but it allows for slight stupidity
// meaning, they may not have read all the master requestFrom() data yet
if(rxBufferIndex < rxBufferLength){
return;
}
// copy twi rx buffer into local read buffer
// this enables new reads to happen in parallel
for(uint8_t i = 0; i < numBytes; ++i){
rxBuffer[i] = inBytes[i];
}
// set rx iterator vars
rxBufferIndex = 0;
rxBufferLength = numBytes;
// alert user program
user_onReceive(numBytes);
}
// behind the scenes function that is called when data is requested
void onRequestService(void)
{
// don't bother if user hasn't registered a callback
if(!user_onRequest){
return;
}
// reset tx buffer iterator vars
// !!! this will kill any pending pre-master sendTo() activity
txBufferIndex = 0;
txBufferLength = 0;
// alert user program
user_onRequest();
}
// sets function called on slave write
void twi_set_on_receive( void (*function)(int) )
{
user_onReceive = function;
}
// sets function called on slave read
void twi_set_on_request( void (*function)(void) )
{
user_onRequest = function;
}

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ds3231/twi.h Normal file
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/*
TwoWire.h - TWI/I2C library for Arduino & Wiring
Copyright (c) 2006 Nicholas Zambetti. All right reserved.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef TwoWire_h
#define TwoWire_h
#include <inttypes.h>
#define BUFFER_LENGTH 32
void twi_init_master(void);
void twi_init_slave(uint8_t);
void twi_begin_transmission(uint8_t);
uint8_t twi_end_transmission(void);
uint8_t twi_request_from(uint8_t, uint8_t);
void twi_send_byte(uint8_t);
void twi_send(uint8_t*, uint8_t);
void twi_send_char(char*);
uint8_t twi_available(void);
uint8_t twi_receive(void);
void twi_set_on_receive( void (*)(int) );
void twi_set_on_request( void (*)(void) );
#endif

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ds3231/usart Submodule

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Subproject commit b2a3b03867858da5d1f8eb955fcbfc106c851ac2