/************************************************************************* Title: Interrupt UART library with receive/transmit circular buffers Author: Peter Fleury http://tinyurl.com/peterfleury File: $Id: uart.c,v 1.15.2.4 2015/09/05 18:33:32 peter Exp $ Software: AVR-GCC 4.x Hardware: any AVR with built-in UART, License: GNU General Public License DESCRIPTION: An interrupt is generated when the UART has finished transmitting or receiving a byte. The interrupt handling routines use circular buffers for buffering received and transmitted data. The UART_RX_BUFFER_SIZE and UART_TX_BUFFER_SIZE variables define the buffer size in bytes. Note that these variables must be a power of 2. USAGE: Refere to the header file uart.h for a description of the routines. See also example test_uart.c. NOTES: Based on Atmel Application Note AVR306 LICENSE: Copyright (C) 2015 Peter Fleury, GNU General Public License Version 3 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 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. *************************************************************************/ #include "uart.h" #include #include #include /* * constants and macros */ /* size of RX/TX buffers */ #define UART_RX_BUFFER_MASK (UART_RX_BUFFER_SIZE - 1) #define UART_TX_BUFFER_MASK (UART_TX_BUFFER_SIZE - 1) #if (UART_RX_BUFFER_SIZE & UART_RX_BUFFER_MASK) #error RX buffer size is not a power of 2 #endif #if (UART_TX_BUFFER_SIZE & UART_TX_BUFFER_MASK) #error TX buffer size is not a power of 2 #endif #if defined(__AVR_AT90S2313__) || defined(__AVR_AT90S4414__) || defined(__AVR_AT90S8515__) || \ defined(__AVR_AT90S4434__) || defined(__AVR_AT90S8535__) || defined(__AVR_ATmega103__) /* old AVR classic or ATmega103 with one UART */ #define UART0_RECEIVE_INTERRUPT UART_RX_vect #define UART0_TRANSMIT_INTERRUPT UART_UDRE_vect #define UART0_STATUS USR #define UART0_CONTROL UCR #define UART0_DATA UDR #define UART0_UDRIE UDRIE #define UART0_UBRRL UBRR #define UART0_BIT_U2X U2X #define UART0_BIT_RXCIE RXCIE #define UART0_BIT_RXEN RXEN #define UART0_BIT_TXEN TXEN #elif defined(__AVR_AT90S2333__) || defined(__AVR_AT90S4433__) /* old AVR classic with one UART */ #define UART0_RECEIVE_INTERRUPT UART_RX_vect #define UART0_TRANSMIT_INTERRUPT UART_UDRE_vect #define UART0_STATUS UCSRA #define UART0_CONTROL UCSRB #define UART0_DATA UDR #define UART0_UDRIE UDRIE #define UART0_UBRRL UBRR #define UART0_BIT_U2X U2X #define UART0_BIT_RXCIE RXCIE #define UART0_BIT_RXEN RXEN #define UART0_BIT_TXEN TXEN #elif defined(__AVR_AT90PWM216__) || defined(__AVR_AT90PWM316__) /* AT90PWN216/316 with one USART */ #define UART0_RECEIVE_INTERRUPT USART_RX_vect #define UART0_TRANSMIT_INTERRUPT USART_UDRE_vect #define UART0_STATUS UCSRA #define UART0_CONTROL UCSRB #define UART0_CONTROLC UCSRC #define UART0_DATA UDR #define UART0_UDRIE UDRIE #define UART0_UBRRL UBRRL #define UART0_UBRRH UBRRH #define UART0_BIT_U2X U2X #define UART0_BIT_RXCIE RXCIE #define UART0_BIT_RXEN RXEN #define UART0_BIT_TXEN TXEN #define UART0_BIT_UCSZ0 UCSZ0 #define UART0_BIT_UCSZ1 UCSZ1 #elif defined(__AVR_ATmega8__) || defined(__AVR_ATmega8A__) || defined(__AVR_ATmega16__) || \ defined(__AVR_ATmega16A__) || defined(__AVR_ATmega32__) || defined(__AVR_ATmega32A__) || \ defined(__AVR_ATmega323__) /* ATmega with one USART */ #define UART0_RECEIVE_INTERRUPT USART_RXC_vect #define UART0_TRANSMIT_INTERRUPT USART_UDRE_vect #define UART0_STATUS UCSRA #define UART0_CONTROL UCSRB #define UART0_CONTROLC UCSRC #define UART0_DATA UDR #define UART0_UDRIE UDRIE #define UART0_UBRRL UBRRL #define UART0_UBRRH UBRRH #define UART0_BIT_U2X U2X #define UART0_BIT_RXCIE RXCIE #define UART0_BIT_RXEN RXEN #define UART0_BIT_TXEN TXEN #define UART0_BIT_UCSZ0 UCSZ0 #define UART0_BIT_UCSZ1 UCSZ1 #define UART0_BIT_URSEL URSEL #elif defined(__AVR_ATmega8515__) || defined(__AVR_ATmega8535__) #define UART0_RECEIVE_INTERRUPT USART_RX_vect #define UART0_TRANSMIT_INTERRUPT USART_UDRE_vect #define UART0_STATUS UCSRA #define UART0_CONTROL UCSRB #define UART0_CONTROLC UCSRC #define UART0_DATA UDR #define UART0_UDRIE UDRIE #define UART0_UBRRL UBRRL #define UART0_UBRRH UBRRH #define UART0_BIT_U2X U2X #define UART0_BIT_RXCIE RXCIE #define UART0_BIT_RXEN RXEN #define UART0_BIT_TXEN TXEN #define UART0_BIT_UCSZ0 UCSZ0 #define UART0_BIT_UCSZ1 UCSZ1 #define UART0_BIT_URSEL URSEL #elif defined(__AVR_ATmega163__) /* ATmega163 with one UART */ #define UART0_RECEIVE_INTERRUPT UART_RX_vect #define UART0_TRANSMIT_INTERRUPT UART_UDRE_vect #define UART0_STATUS UCSRA #define UART0_CONTROL UCSRB #define UART0_DATA UDR #define UART0_UDRIE UDRIE #define UART0_UBRRL UBRR #define UART0_UBRRH UBRRHI #define UART0_BIT_U2X U2X #define UART0_BIT_RXCIE RXCIE #define UART0_BIT_RXEN RXEN #define UART0_BIT_TXEN TXEN #elif defined(__AVR_ATmega162__) /* ATmega with two USART */ #define ATMEGA_USART1 #define UART0_RECEIVE_INTERRUPT USART0_RXC_vect #define UART1_RECEIVE_INTERRUPT USART1_RXC_vect #define UART0_TRANSMIT_INTERRUPT USART0_UDRE_vect #define UART1_TRANSMIT_INTERRUPT USART1_UDRE_vect #define UART0_STATUS UCSR0A #define UART0_CONTROL UCSR0B #define UART0_CONTROLC UCSR0C #define UART0_DATA UDR0 #define UART0_UDRIE UDRIE0 #define UART0_UBRRL UBRR0L #define UART0_UBRRH UBRR0H #define UART0_BIT_URSEL URSEL0 #define UART0_BIT_U2X U2X0 #define UART0_BIT_RXCIE RXCIE0 #define UART0_BIT_RXEN RXEN0 #define UART0_BIT_TXEN TXEN0 #define UART0_BIT_UCSZ0 UCSZ00 #define UART0_BIT_UCSZ1 UCSZ01 #define UART1_STATUS UCSR1A #define UART1_CONTROL UCSR1B #define UART1_CONTROLC UCSR1C #define UART1_DATA UDR1 #define UART1_UDRIE UDRIE1 #define UART1_UBRRL UBRR1L #define UART1_UBRRH UBRR1H #define UART1_BIT_URSEL URSEL1 #define UART1_BIT_U2X U2X1 #define UART1_BIT_RXCIE RXCIE1 #define UART1_BIT_RXEN RXEN1 #define UART1_BIT_TXEN TXEN1 #define UART1_BIT_UCSZ0 UCSZ10 #define UART1_BIT_UCSZ1 UCSZ11 #elif defined(__AVR_ATmega161__) /* ATmega with UART */ #error "AVR ATmega161 currently not supported by this libaray !" #elif defined(__AVR_ATmega169__) /* ATmega with one USART */ #define UART0_RECEIVE_INTERRUPT USART0_RX_vect #define UART0_TRANSMIT_INTERRUPT USART0_UDRE_vect #define UART0_STATUS UCSRA #define UART0_CONTROL UCSRB #define UART0_CONTROLC UCSRC #define UART0_DATA UDR #define UART0_UDRIE UDRIE #define UART0_UBRRL UBRRL #define UART0_UBRRH UBRRH #define UART0_BIT_U2X U2X #define UART0_BIT_RXCIE RXCIE #define UART0_BIT_RXEN RXEN #define UART0_BIT_TXEN TXEN #define UART0_BIT_UCSZ0 UCSZ0 #define UART0_BIT_UCSZ1 UCSZ1 #elif defined(__AVR_ATmega48__) || defined(__AVR_ATmega48A__) || defined(__AVR_ATmega48P__) || \ defined(__AVR_ATmega48PA__) || defined(__AVR_ATmega48PB__) || defined(__AVR_ATmega88__) || \ defined(__AVR_ATmega88A__) || defined(__AVR_ATmega88P__) || defined(__AVR_ATmega88PA__) || \ defined(__AVR_ATmega88PB__) || defined(__AVR_ATmega168__) || defined(__AVR_ATmega168A__) || \ defined(__AVR_ATmega168P__) || defined(__AVR_ATmega168PA__) || defined(__AVR_ATmega168PB__) || \ defined(__AVR_ATmega328__) || defined(__AVR_ATmega328P__) || defined(__AVR_ATmega3250__) || \ defined(__AVR_ATmega3290__) || defined(__AVR_ATmega6450__) || defined(__AVR_ATmega6490__) /* ATmega with one USART */ #define UART0_RECEIVE_INTERRUPT USART_RX_vect #define UART0_TRANSMIT_INTERRUPT USART_UDRE_vect #define UART0_STATUS UCSR0A #define UART0_CONTROL UCSR0B #define UART0_CONTROLC UCSR0C #define UART0_DATA UDR0 #define UART0_UDRIE UDRIE0 #define UART0_UBRRL UBRR0L #define UART0_UBRRH UBRR0H #define UART0_BIT_U2X U2X0 #define UART0_BIT_RXCIE RXCIE0 #define UART0_BIT_RXEN RXEN0 #define UART0_BIT_TXEN TXEN0 #define UART0_BIT_UCSZ0 UCSZ00 #define UART0_BIT_UCSZ1 UCSZ01 #elif defined(__AVR_ATtiny2313__) || defined(__AVR_ATtiny2313A__) || defined(__AVR_ATtiny4313__) /* ATtiny with one USART */ #define UART0_RECEIVE_INTERRUPT USART_RX_vect #define UART0_TRANSMIT_INTERRUPT USART_UDRE_vect #define UART0_STATUS UCSRA #define UART0_CONTROL UCSRB #define UART0_CONTROLC UCSRC #define UART0_DATA UDR #define UART0_UDRIE UDRIE #define UART0_UBRRL UBRRL #define UART0_UBRRH UBRRH #define UART0_BIT_U2X U2X #define UART0_BIT_RXCIE RXCIE #define UART0_BIT_RXEN RXEN #define UART0_BIT_TXEN TXEN #define UART0_BIT_UCSZ0 UCSZ0 #define UART0_BIT_UCSZ1 UCSZ1 #elif defined(__AVR_ATmega329__) || defined(__AVR_ATmega649__) || defined(__AVR_ATmega3290__) || \ defined(__AVR_ATmega6490__) || defined(__AVR_ATmega169A__) || defined(__AVR_ATmega169PA__) || \ defined(__AVR_ATmega329A__) || defined(__AVR_ATmega329PA__) || defined(__AVR_ATmega3290A__) || \ defined(__AVR_ATmega3290PA__) || defined(__AVR_ATmega649A__) || defined(__AVR_ATmega649P__) || \ defined(__AVR_ATmega6490A__) || defined(__AVR_ATmega6490P__) || defined(__AVR_ATmega165__) || \ defined(__AVR_ATmega325__) || defined(__AVR_ATmega645__) || defined(__AVR_ATmega3250__) || \ defined(__AVR_ATmega6450__) || defined(__AVR_ATmega165A__) || defined(__AVR_ATmega165PA__) || \ defined(__AVR_ATmega325A__) || defined(__AVR_ATmega325PA__) || defined(__AVR_ATmega3250A__) || \ defined(__AVR_ATmega3250PA__) || defined(__AVR_ATmega645A__) || defined(__AVR_ATmega645PA__) || \ defined(__AVR_ATmega6450A__) || defined(__AVR_ATmega6450PA__) || defined(__AVR_ATmega644__) /* ATmega with one USART */ #define UART0_RECEIVE_INTERRUPT USART0_RX_vect #define UART0_TRANSMIT_INTERRUPT USART0_UDRE_vect #define UART0_STATUS UCSR0A #define UART0_CONTROL UCSR0B #define UART0_CONTROLC UCSR0C #define UART0_DATA UDR0 #define UART0_UDRIE UDRIE0 #define UART0_UBRRL UBRR0L #define UART0_UBRRH UBRR0H #define UART0_BIT_U2X U2X0 #define UART0_BIT_RXCIE RXCIE0 #define UART0_BIT_RXEN RXEN0 #define UART0_BIT_TXEN TXEN0 #define UART0_BIT_UCSZ0 UCSZ00 #define UART0_BIT_UCSZ1 UCSZ01 #elif defined(__AVR_ATmega64__) || defined(__AVR_ATmega128__) || defined(__AVR_ATmega128A__) || \ defined(__AVR_ATmega640__) || defined(__AVR_ATmega1280__) || defined(__AVR_ATmega1281__) || \ defined(__AVR_ATmega2560__) || defined(__AVR_ATmega2561__) || defined(__AVR_ATmega164P__) || \ defined(__AVR_ATmega324P__) || defined(__AVR_ATmega644P__) || defined(__AVR_ATmega164A__) || \ defined(__AVR_ATmega164PA__) || defined(__AVR_ATmega324A__) || defined(__AVR_ATmega324PA__) || \ defined(__AVR_ATmega644A__) || defined(__AVR_ATmega644PA__) || defined(__AVR_ATmega1284__) || \ defined(__AVR_ATmega1284P__) || defined(__AVR_ATtiny1634__) /* ATmega with two USART */ #define ATMEGA_USART1 #define UART0_RECEIVE_INTERRUPT USART0_RX_vect #define UART1_RECEIVE_INTERRUPT USART1_RX_vect #define UART0_TRANSMIT_INTERRUPT USART0_UDRE_vect #define UART1_TRANSMIT_INTERRUPT USART1_UDRE_vect #define UART0_STATUS UCSR0A #define UART0_CONTROL UCSR0B #define UART0_CONTROLC UCSR0C #define UART0_DATA UDR0 #define UART0_UDRIE UDRIE0 #define UART0_UBRRL UBRR0L #define UART0_UBRRH UBRR0H #define UART0_BIT_U2X U2X0 #define UART0_BIT_RXCIE RXCIE0 #define UART0_BIT_RXEN RXEN0 #define UART0_BIT_TXEN TXEN0 #define UART0_BIT_UCSZ0 UCSZ00 #define UART0_BIT_UCSZ1 UCSZ01 #define UART1_STATUS UCSR1A #define UART1_CONTROL UCSR1B #define UART1_CONTROLC UCSR1C #define UART1_DATA UDR1 #define UART1_UDRIE UDRIE1 #define UART1_UBRRL UBRR1L #define UART1_UBRRH UBRR1H #define UART1_BIT_U2X U2X1 #define UART1_BIT_RXCIE RXCIE1 #define UART1_BIT_RXEN RXEN1 #define UART1_BIT_TXEN TXEN1 #define UART1_BIT_UCSZ0 UCSZ10 #define UART1_BIT_UCSZ1 UCSZ11 #elif defined(__AVR_ATmega8U2__) || defined(__AVR_ATmega16U2__) || defined(__AVR_ATmega32U2__) || \ defined(__AVR_ATmega16U4__) || defined(__AVR_ATmega32U4__) || defined(__AVR_AT90USB82__) || \ defined(__AVR_AT90USB162__) || defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB1286__) || \ defined(__AVR_AT90USB647__) || defined(__AVR_AT90USB1287__) #define UART0_RECEIVE_INTERRUPT USART1_RX_vect #define UART0_TRANSMIT_INTERRUPT USART1_UDRE_vect #define UART0_STATUS UCSR1A #define UART0_CONTROL UCSR1B #define UART0_CONTROLC UCSR1C #define UART0_DATA UDR1 #define UART0_UDRIE UDRIE1 #define UART0_UBRRL UBRR1L #define UART0_UBRRH UBRR1H #define UART0_BIT_U2X U2X1 #define UART0_BIT_RXCIE RXCIE1 #define UART0_BIT_RXEN RXEN1 #define UART0_BIT_TXEN TXEN1 #define UART0_BIT_UCSZ0 UCSZ10 #define UART0_BIT_UCSZ1 UCSZ11 #else #error "no UART definition for MCU available" #endif /* * module global variables */ static volatile unsigned char UART_TxBuf[UART_TX_BUFFER_SIZE]; static volatile unsigned char UART_RxBuf[UART_RX_BUFFER_SIZE]; static volatile unsigned char UART_TxHead; static volatile unsigned char UART_TxTail; static volatile unsigned char UART_RxHead; static volatile unsigned char UART_RxTail; static volatile unsigned char UART_LastRxError; #if defined(ATMEGA_USART1) static volatile unsigned char UART1_TxBuf[UART_TX_BUFFER_SIZE]; static volatile unsigned char UART1_RxBuf[UART_RX_BUFFER_SIZE]; static volatile unsigned char UART1_TxHead; static volatile unsigned char UART1_TxTail; static volatile unsigned char UART1_RxHead; static volatile unsigned char UART1_RxTail; static volatile unsigned char UART1_LastRxError; #endif ISR(UART0_RECEIVE_INTERRUPT) /************************************************************************* Function: UART Receive Complete interrupt Purpose: called when the UART has received a character **************************************************************************/ { unsigned char tmphead; unsigned char data; unsigned char usr; unsigned char lastRxError; /* read UART status register and UART data register */ usr = UART0_STATUS; data = UART0_DATA; /* get FEn (Frame Error) DORn (Data OverRun) UPEn (USART Parity Error) bits */ #if defined(FE) && defined(DOR) && defined(UPE) lastRxError = usr & (_BV(FE) | _BV(DOR) | _BV(UPE)); #elif defined(FE0) && defined(DOR0) && defined(UPE0) lastRxError = usr & (_BV(FE0) | _BV(DOR0) | _BV(UPE0)); #elif defined(FE1) && defined(DOR1) && defined(UPE1) lastRxError = usr & (_BV(FE1) | _BV(DOR1) | _BV(UPE1)); #elif defined(FE) && defined(DOR) lastRxError = usr & (_BV(FE) | _BV(DOR)); #endif /* calculate buffer index */ tmphead = (UART_RxHead + 1) & UART_RX_BUFFER_MASK; if (tmphead == UART_RxTail) { /* error: receive buffer overflow */ lastRxError = UART_BUFFER_OVERFLOW >> 8; } else { /* store new index */ UART_RxHead = tmphead; /* store received data in buffer */ UART_RxBuf[tmphead] = data; } UART_LastRxError |= lastRxError; } ISR(UART0_TRANSMIT_INTERRUPT) /************************************************************************* Function: UART Data Register Empty interrupt Purpose: called when the UART is ready to transmit the next byte **************************************************************************/ { unsigned char tmptail; if (UART_TxHead != UART_TxTail) { /* calculate and store new buffer index */ tmptail = (UART_TxTail + 1) & UART_TX_BUFFER_MASK; UART_TxTail = tmptail; /* get one byte from buffer and write it to UART */ UART0_DATA = UART_TxBuf[tmptail]; /* start transmission */ } else { /* tx buffer empty, disable UDRE interrupt */ UART0_CONTROL &= ~_BV(UART0_UDRIE); } } /************************************************************************* Function: uart_init() Purpose: initialize UART and set baudrate Input: baudrate using macro UART_BAUD_SELECT() Returns: none **************************************************************************/ void uart_init(unsigned int baudrate) { UART_TxHead = 0; UART_TxTail = 0; UART_RxHead = 0; UART_RxTail = 0; #ifdef UART_TEST #ifndef UART0_BIT_U2X #warning "UART0_BIT_U2X not defined" #endif #ifndef UART0_UBRRH #warning "UART0_UBRRH not defined" #endif #ifndef UART0_CONTROLC #warning "UART0_CONTROLC not defined" #endif #if defined(URSEL) || defined(URSEL0) #ifndef UART0_BIT_URSEL #warning "UART0_BIT_URSEL not defined" #endif #endif #endif /* Set baud rate */ if (baudrate & 0x8000) { #if UART0_BIT_U2X UART0_STATUS = (1 << UART0_BIT_U2X); // Enable 2x speed #endif } #if defined(UART0_UBRRH) UART0_UBRRH = (unsigned char)((baudrate >> 8) & 0x80); #endif UART0_UBRRL = (unsigned char)(baudrate & 0x00FF); /* Enable USART receiver and transmitter and receive complete interrupt */ UART0_CONTROL = _BV(UART0_BIT_RXCIE) | (1 << UART0_BIT_RXEN) | (1 << UART0_BIT_TXEN); /* Set frame format: asynchronous, 8data, no parity, 1stop bit */ #ifdef UART0_CONTROLC #ifdef UART0_BIT_URSEL UART0_CONTROLC = (1 << UART0_BIT_URSEL) | (1 << UART0_BIT_UCSZ1) | (1 << UART0_BIT_UCSZ0); #else UART0_CONTROLC = (1 << UART0_BIT_UCSZ1) | (1 << UART0_BIT_UCSZ0); #endif #endif } /* uart_init */ /************************************************************************* Function: uart_getc() Purpose: return byte from ringbuffer Returns: lower byte: received byte from ringbuffer higher byte: last receive error **************************************************************************/ unsigned int uart_getc(void) { unsigned char tmptail; unsigned char data; unsigned char lastRxError; if (UART_RxHead == UART_RxTail) { return UART_NO_DATA; /* no data available */ } /* calculate buffer index */ tmptail = (UART_RxTail + 1) & UART_RX_BUFFER_MASK; /* get data from receive buffer */ data = UART_RxBuf[tmptail]; lastRxError = UART_LastRxError; /* store buffer index */ UART_RxTail = tmptail; UART_LastRxError = 0; return (lastRxError << 8) + data; } /* uart_getc */ /************************************************************************* Function: uart_putc() Purpose: write byte to ringbuffer for transmitting via UART Input: byte to be transmitted Returns: none **************************************************************************/ void uart_putc(unsigned char data) { unsigned char tmphead; tmphead = (UART_TxHead + 1) & UART_TX_BUFFER_MASK; while (tmphead == UART_TxTail) { ; /* wait for free space in buffer */ } UART_TxBuf[tmphead] = data; UART_TxHead = tmphead; /* enable UDRE interrupt */ UART0_CONTROL |= _BV(UART0_UDRIE); } /* uart_putc */ /************************************************************************* Function: uart_puts() Purpose: transmit string to UART Input: string to be transmitted Returns: none **************************************************************************/ void uart_puts(const char *s) { while (*s) uart_putc(*s++); } /* uart_puts */ /************************************************************************* Function: uart_puts_p() Purpose: transmit string from program memory to UART Input: program memory string to be transmitted Returns: none **************************************************************************/ void uart_puts_p(const char *progmem_s) { register char c; while ((c = pgm_read_byte(progmem_s++))) uart_putc(c); } /* uart_puts_p */ /* * these functions are only for ATmegas with two USART */ #if defined(ATMEGA_USART1) ISR(UART1_RECEIVE_INTERRUPT) /************************************************************************* Function: UART1 Receive Complete interrupt Purpose: called when the UART1 has received a character **************************************************************************/ { unsigned char tmphead; unsigned char data; unsigned char usr; unsigned char lastRxError; /* read UART status register and UART data register */ usr = UART1_STATUS; data = UART1_DATA; /* get FEn (Frame Error) DORn (Data OverRun) UPEn (USART Parity Error) bits */ lastRxError = usr & (_BV(FE1) | _BV(DOR1) | _BV(UPE1)); /* calculate buffer index */ tmphead = (UART1_RxHead + 1) & UART_RX_BUFFER_MASK; if (tmphead == UART1_RxTail) { /* error: receive buffer overflow */ lastRxError = UART_BUFFER_OVERFLOW >> 8; } else { /* store new index */ UART1_RxHead = tmphead; /* store received data in buffer */ UART1_RxBuf[tmphead] = data; } UART1_LastRxError |= lastRxError; } ISR(UART1_TRANSMIT_INTERRUPT) /************************************************************************* Function: UART1 Data Register Empty interrupt Purpose: called when the UART1 is ready to transmit the next byte **************************************************************************/ { unsigned char tmptail; if (UART1_TxHead != UART1_TxTail) { /* calculate and store new buffer index */ tmptail = (UART1_TxTail + 1) & UART_TX_BUFFER_MASK; UART1_TxTail = tmptail; /* get one byte from buffer and write it to UART */ UART1_DATA = UART1_TxBuf[tmptail]; /* start transmission */ } else { /* tx buffer empty, disable UDRE interrupt */ UART1_CONTROL &= ~_BV(UART1_UDRIE); } } /************************************************************************* Function: uart1_init() Purpose: initialize UART1 and set baudrate Input: baudrate using macro UART_BAUD_SELECT() Returns: none **************************************************************************/ void uart1_init(unsigned int baudrate) { UART1_TxHead = 0; UART1_TxTail = 0; UART1_RxHead = 0; UART1_RxTail = 0; #ifdef UART_TEST #ifndef UART1_BIT_U2X #warning "UART1_BIT_U2X not defined" #endif #ifndef UART1_UBRRH #warning "UART1_UBRRH not defined" #endif #ifndef UART1_CONTROLC #warning "UART1_CONTROLC not defined" #endif #if defined(URSEL) || defined(URSEL1) #ifndef UART1_BIT_URSEL #warning "UART1_BIT_URSEL not defined" #endif #endif #endif /* Set baud rate */ if (baudrate & 0x8000) { #if UART1_BIT_U2X UART1_STATUS = (1 << UART1_BIT_U2X); // Enable 2x speed #endif } UART1_UBRRH = (unsigned char)((baudrate >> 8) & 0x80); UART1_UBRRL = (unsigned char)baudrate; /* Enable USART receiver and transmitter and receive complete interrupt */ UART1_CONTROL = _BV(UART1_BIT_RXCIE) | (1 << UART1_BIT_RXEN) | (1 << UART1_BIT_TXEN); /* Set frame format: asynchronous, 8data, no parity, 1stop bit */ #ifdef UART1_BIT_URSEL UART1_CONTROLC = (1 << UART1_BIT_URSEL) | (1 << UART1_BIT_UCSZ1) | (1 << UART1_BIT_UCSZ0); #else UART1_CONTROLC = (1 << UART1_BIT_UCSZ1) | (1 << UART1_BIT_UCSZ0); #endif } /* uart_init */ /************************************************************************* Function: uart1_getc() Purpose: return byte from ringbuffer Returns: lower byte: received byte from ringbuffer higher byte: last receive error **************************************************************************/ unsigned int uart1_getc(void) { unsigned char tmptail; unsigned int data; unsigned char lastRxError; if (UART1_RxHead == UART1_RxTail) { return UART_NO_DATA; /* no data available */ } /* calculate buffer index */ tmptail = (UART1_RxTail + 1) & UART_RX_BUFFER_MASK; /* get data from receive buffer */ data = UART1_RxBuf[tmptail]; lastRxError = UART1_LastRxError; /* store buffer index */ UART1_RxTail = tmptail; UART1_LastRxError = 0; return (lastRxError << 8) + data; } /* uart1_getc */ /************************************************************************* Function: uart1_putc() Purpose: write byte to ringbuffer for transmitting via UART Input: byte to be transmitted Returns: none **************************************************************************/ void uart1_putc(unsigned char data) { unsigned char tmphead; tmphead = (UART1_TxHead + 1) & UART_TX_BUFFER_MASK; while (tmphead == UART1_TxTail) { ; /* wait for free space in buffer */ } UART1_TxBuf[tmphead] = data; UART1_TxHead = tmphead; /* enable UDRE interrupt */ UART1_CONTROL |= _BV(UART1_UDRIE); } /* uart1_putc */ /************************************************************************* Function: uart1_puts() Purpose: transmit string to UART1 Input: string to be transmitted Returns: none **************************************************************************/ void uart1_puts(const char *s) { while (*s) uart1_putc(*s++); } /* uart1_puts */ /************************************************************************* Function: uart1_puts_p() Purpose: transmit string from program memory to UART1 Input: program memory string to be transmitted Returns: none **************************************************************************/ void uart1_puts_p(const char *progmem_s) { register char c; while ((c = pgm_read_byte(progmem_s++))) uart1_putc(c); } /* uart1_puts_p */ #endif