/* 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 3 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*
*/
/* This library handles the Two-Wire Interface (TWI)/Inter-Integrated Circuit (I²C) configuration
* based on demo by Ruwan Jayanetti from AVR libc examples
* http://www.nongnu.org/avr-libc/user-manual/group__twi__demo.html
*/
#include // Standard Integer Types
#include // General utilities
#include // Boolean
#include // AVR device-specific IO definitions
#include // 2-wire TWSR values
#include // definitions
/* initialize 2-wire interface */
void twi_init(void)
{
TWSR &= ~((1< bytes inyo using 2-wire interface, starting at
* returns if it succeeded
* 16 bits address is not supported
*/
bool twi_read_bytes(uint8_t addr, uint8_t len, uint8_t *buf)
{
uint16_t retry = 0; // number of retries
bool rc = false; // return code
/* number of times to retry */
restart:
if (retry++ >= MAX_ITER) {
return false;
}
/* first cycle: master transmitter mode */
start:
/* send start */
TWCR = (1< 0) {
if (len > 1) {
TWCR = (1< bytes from on 2-wire interface starting at
* returns if it successed
* 16 bits address is not supported
* ensure yourself the size of pages to be written
*/
bool twi_write_bytes(uint8_t addr, uint8_t len, uint8_t *buf)
{
uint16_t retry = 0; // number of retries
bool rc = false; // return code
/* number of times to retry */
restart:
if (retry++ >= MAX_ITER) {
return false;
}
/* master transmit mode */
start:
/* start */
TWCR = (1< 0; len--) {
TWDR = *buf++;
TWCR = (1<