234 lines
6.1 KiB
C
234 lines
6.1 KiB
C
/*
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* Copyright (c) 2010, Swedish Institute of Computer Science.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the Institute nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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*/
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/**
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* \file
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* i2c core functions
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* \author
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* Robert Olsson <robert@radio-sensors.com>
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*/
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#include <avr/pgmspace.h>
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#include <avr/pgmspace.h>
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#include <avr/sleep.h>
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#include <avr/wdt.h>
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#include "dev/watchdog.h"
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#include "contiki.h"
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#include "i2c.h"
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#include <compat/twi.h>
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#include <stdio.h>
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#include <string.h>
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#include "dev/co2_sa_kxx-sensor.h"
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void
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i2c_init(uint32_t speed)
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{
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/* initialize TWI clock: 100 kHz clock, TWPS = 0 => prescaler = 1 */
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TWSR = 0; /* no prescaler */
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TWBR = ((F_CPU / speed) - 16) / 2; /* must be > 10 for stable operation */
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}
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uint8_t
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i2c_start(uint8_t addr)
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{
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uint8_t twst;
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uint32_t n;
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/* Send START condition */
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TWCR = (1 << TWINT) | (1 << TWSTA) | (1 << TWEN);
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/* Wait until transmission completed */
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for(n = 0; n < 100000 && !(TWCR & (1 << TWINT)); n++) {
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}
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if(n >= 100000) {
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return 1;
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}
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/* check value of TWI Status Register. Mask prescaler bits. */
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twst = TW_STATUS & 0xF8;
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if((twst != TW_START) && (twst != TW_REP_START)) {
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return 1;
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}
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/* send device address */
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TWDR = addr;
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TWCR = (1 << TWINT) | (1 << TWEN);
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/* wail until transmission completed and ACK/NACK has been received */
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for(n = 0; n < 100000 && !(TWCR & (1 << TWINT)); n++) {
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}
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if(n >= 100000) {
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return 1;
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}
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/* check value of TWI Status Register. Mask prescaler bits. */
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twst = TW_STATUS & 0xF8;
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if((twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK)) {
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return 1;
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}
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return 0;
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}
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void
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i2c_start_wait(uint8_t addr)
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{
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uint8_t twst;
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while ( 1 )
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{
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// send START condition
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TWCR = (1<<TWINT) | (1<<TWSTA) | (1<<TWEN);
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// wait until transmission completed
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while(!(TWCR & (1<<TWINT)));
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// check value of TWI Status Register. Mask prescaler bits.
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twst = TW_STATUS & 0xF8;
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if ( (twst != TW_START) && (twst != TW_REP_START)) continue;
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// send device address
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TWDR = addr;
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TWCR = (1<<TWINT) | (1<<TWEN);
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// wail until transmission completed
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while(!(TWCR & (1<<TWINT)));
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// check value of TWI Status Register. Mask prescaler bits.
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twst = TW_STATUS & 0xF8;
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if ( (twst == TW_MT_SLA_NACK )||(twst ==TW_MR_DATA_NACK) )
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{
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/* device busy, send stop condition to terminate write operation */
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TWCR = (1<<TWINT) | (1<<TWEN) | (1<<TWSTO);
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// wait until stop condition is executed and bus released
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while(TWCR & (1<<TWSTO));
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continue;
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}
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//if( twst != TW_MT_SLA_ACK) return 1;
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break;
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}
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}
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void
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i2c_stop(void)
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{
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TWCR = (1 << TWINT) | (1 << TWSTO) | (1 << TWEN);
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/* wait until ready */
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while(TWCR & (1<<TWSTO));
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}
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void
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i2c_write(uint8_t u8data)
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{
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TWDR = u8data;
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TWCR = (1 << TWINT) | (1 << TWEN);
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while((TWCR & (1 << TWINT)) == 0) ;
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}
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uint8_t
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i2c_readAck(void)
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{
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TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWEA);
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while((TWCR & (1 << TWINT)) == 0) ;
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return TWDR;
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}
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uint8_t
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i2c_readNak(void)
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{
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TWCR = (1 << TWINT) | (1 << TWEN);
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while((TWCR & (1 << TWINT)) == 0) ;
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return TWDR;
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}
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static void
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print_delim(int p, char *s, const char *d)
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{
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if(p) {
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printf("%s", d);
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}
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printf("%s", s);
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}
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void
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i2c_write_mem(uint8_t addr, uint8_t reg, uint8_t value)
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{
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i2c_start(addr | I2C_WRITE);
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i2c_write(reg);
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i2c_write(value);
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i2c_stop();
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}
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void
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i2c_read_mem(uint8_t addr, uint8_t reg, uint8_t buf[], uint8_t bytes)
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{
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uint8_t i = 0;
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i2c_start(addr | I2C_WRITE);
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i2c_write(reg);
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i2c_start(addr | I2C_READ);
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for(i = 0; i < bytes; i++) {
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if(i == bytes - 1) {
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buf[i] = i2c_readNak();
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} else {
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buf[i] = i2c_readAck();
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}
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}
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i2c_stop();
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}
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void
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i2c_at24mac_read(char *buf, uint8_t eui64)
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{
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if(eui64) {
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i2c_read_mem(I2C_AT24MAC_ADDR, 0x98, (uint8_t *)buf, 8);
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}
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/* 128bit unique serial number */
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else {
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i2c_read_mem(I2C_AT24MAC_ADDR, 0x80, (uint8_t *)buf, 16);
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}
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}
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uint16_t
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i2c_probe(void)
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{
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int p = 0;
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const char *del = ",";
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uint16_t probed = 0;
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watchdog_periodic();
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if(!i2c_start(I2C_AT24MAC_ADDR)) {
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i2c_stop();
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probed |= I2C_AT24MAC;
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print_delim(p++, "AT24MAC", del);
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}
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watchdog_periodic();
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if(!i2c_start(I2C_SHT2X_ADDR)) {
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i2c_stop();
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probed |= I2C_SHT2X;
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print_delim(p++, "SHT2X", del);
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}
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watchdog_periodic();
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if(!i2c_start(I2C_CO2SA_ADDR)) {
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i2c_stop();
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probed |= I2C_CO2SA;
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print_delim(p++, "CO2SA", del);
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}
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watchdog_periodic();
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if(!i2c_start(I2C_BME280_ADDR)) {
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i2c_stop();
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probed |= I2C_BME280;
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print_delim(p++, "BME280", del);
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}
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return probed;
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}
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