git.rot13.org Git - simavr/blob - examples/board_i2ctest/atmega1280_i2ctest.c

   1 /*
   2         atmega48_i2ctest.c
   3
   4         Copyright 2008-2011 Michel Pollet <buserror@gmail.com>
   5
   6         This file is part of simavr.
   7
   8         simavr is free software: you can redistribute it and/or modify
   9         it under the terms of the GNU General Public License as published by
  10         the Free Software Foundation, either version 3 of the License, or
  11         (at your option) any later version.
  12
  13         simavr is distributed in the hope that it will be useful,
  14         but WITHOUT ANY WARRANTY; without even the implied warranty of
  15         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16         GNU General Public License for more details.
  17
  18         You should have received a copy of the GNU General Public License
  19         along with simavr.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include <avr/io.h>
  23 #include <avr/interrupt.h>
  24 #include <avr/sleep.h>
  25
  26 // for linker, emulator, and programmer's sake
  27 #include "avr_mcu_section.h"
  28 AVR_MCU(F_CPU, "atmega1280");
  29
  30 #include "../shared/avr_twi_master.h"
  31
  32 #include <stdio.h>
  33
  34 static int uart_putchar(char c, FILE *stream) {
  35   if (c == '\n')
  36     uart_putchar('\r', stream);
  37   loop_until_bit_is_set(UCSR0A, UDRE0);
  38   UDR0 = c;
  39   return 0;
  40 }
  41
  42 static FILE mystdout = FDEV_SETUP_STREAM(uart_putchar, NULL,
  43                                          _FDEV_SETUP_WRITE);
  44
  45 int main()
  46 {
  47         stdout = &mystdout;
  48
  49         sei();
  50
  51         TWI_Master_Initialise();
  52
  53         {       // write 2 bytes at some random address
  54                 uint8_t msg[8] = {
  55                                 0xa0, // TWI address,
  56                                 0xaa, 0x01, // eeprom address, in little endian
  57                                 0xde, 0xad,     // data bytes
  58                 };
  59                 TWI_Start_Transceiver_With_Data(msg, 5, 1);
  60
  61                 while (TWI_Transceiver_Busy())
  62                         sleep_mode();
  63         }
  64         {
  65                 uint8_t msg[8] = {
  66                                 0xa0, // TWI address,
  67                                 0xa8, 0x01, // eeprom address, in little endian
  68                 };
  69                 TWI_Start_Transceiver_With_Data(msg, 3, 0); // dont send stop!
  70
  71                 while (TWI_Transceiver_Busy())
  72                         sleep_mode();
  73         }
  74         {
  75                 uint8_t msg[9] = {
  76                                 0xa0 + 1, // TWI address,
  77                 };
  78                 TWI_Start_Transceiver_With_Data(msg, 9, 1); // write 1 byte, read 8, send stop
  79
  80                 while (TWI_Transceiver_Busy())
  81                         sleep_mode();
  82         }
  83         cli();
  84         sleep_mode();
  85 }
  86