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/*
atmega48_i2ctest.c
Copyright 2008-2011 Michel Pollet <buserror@gmail.com>
This file is part of simavr.
simavr 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 3 of the License, or
(at your option) any later version.
simavr 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.
You should have received a copy of the GNU General Public License
along with simavr. If not, see <http://www.gnu.org/licenses/>.
*/
#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/sleep.h>
// for linker, emulator, and programmer's sake
#include "avr_mcu_section.h"
AVR_MCU(F_CPU, "atmega1280");
#include "../shared/avr_twi_master.h"
#include "../shared/twimaster.h"
#include <stdio.h>
#define EEPROM_ADDR 0xA0
static int uart_putchar(char c, FILE *stream) {
if (c == '\n')
uart_putchar('\r', stream);
loop_until_bit_is_set(UCSR0A, UDRE0);
UDR0 = c;
return 0;
}
static FILE mystdout = FDEV_SETUP_STREAM(uart_putchar, NULL,
_FDEV_SETUP_WRITE);
/*
static void
test_twi_with_atmel_driver(void)
{
TWI_Master_Initialise();
{ // write 2 bytes at some random address
uint8_t msg[8] = {
EEPROM_ADDR, // TWI address,
0xaa, 0x01, // eeprom address, in little endian
0xde, 0xad, // data bytes
};
TWI_Start_Transceiver_With_Data(msg, 5, 1);
while (TWI_Transceiver_Busy())
sleep_mode();
}
{
uint8_t msg[8] = {
EEPROM_ADDR, // TWI address,
0xa8, 0x01, // eeprom address, in little endian
};
TWI_Start_Transceiver_With_Data(msg, 3, 0); // dont send stop!
while (TWI_Transceiver_Busy())
sleep_mode();
}
{
uint8_t msg[9] = {
EEPROM_ADDR + 1, // TWI address,
};
TWI_Start_Transceiver_With_Data(msg, 9, 1); // write 1 byte, read 8, send stop
while (TWI_Transceiver_Busy())
sleep_mode();
}
}
*/
/*
* Tests the TWI using a commonly used and non-interrupt driven
* alternative to the Atmel driver:
*
* "I2C master library using hardware TWI interface"
* Author: Peter Fleury <pfleury@gmx.ch> http://jump.to/fleury
*/
static void
test_twi_with_pf_driver(void)
{
/*
* This init followed by a start condition is enough to overwrite all TWI
* related bits set by TWI_Master_Initialise () in the Atmel driver.
*/
i2c_init();
i2c_start(EEPROM_ADDR + I2C_WRITE);
// eeprom address, in little endian
i2c_write(0xaa);
i2c_write(0x01);
// data bytes
i2c_write(0xd0);
i2c_write(0x0d);
i2c_stop();
i2c_start(EEPROM_ADDR + I2C_WRITE);
// set address
i2c_write(0xa8);
i2c_write(0x01);
// Don't stop
// Read back data
i2c_start (EEPROM_ADDR + I2C_READ);
for (uint8_t i = 0; i < 8; ++i) {
i2c_readNak();
};
i2c_stop();
}
int main()
{
stdout = &mystdout;
sei();
/*
test_twi_with_atmel_driver();
*/
/*
* This should produce *exactly* the same output as above, except
* the data written should be D00D as opposed to DEAD.
*/
test_twi_with_pf_driver ();
cli();
sleep_mode();
}
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