at30tse75x.c
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/*
* Copyright (C) Daniel Krebs
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup drivers_at30tse75x
* @file
* @brief Driver for the AT30TSE75x temperature sensor with serial EEPROM
*
* @author Daniel Krebs <github@daniel-krebs.net>
*/
#include "periph/i2c.h"
#include "xtimer.h"
#include "at30tse75x.h"
#define ENABLE_DEBUG (0)
#include "debug.h"
#define AT30TSE75X_BUS_FREE_TIME_TICKS (xtimer_ticks_from_usec(AT30TSE75X_BUS_FREE_TIME_US))
static inline float temperature_to_float(uint16_t temp)
{
/* Integer part is 8-bit signed */
int8_t temp_int = (temp & AT30TSE75X_INTEGER_MASK) >>
AT30TSE75X_INTEGER_SHIFT;
/* Fractional part is multiple of 0.0625 */
uint8_t frac_multiplier = (temp & AT30TSE75X_FRACTIONAL_MASK) >>
AT30TSE75X_FRACTIONAL_SHIFT;
return temp_int + (frac_multiplier * AT30TSE75X_FRACTIONAL_BASE);
}
static int at30tse75x_get_register(const at30tse75x_t *dev, uint8_t reg, uint16_t* data)
{
i2c_acquire(dev->i2c);
xtimer_spin(AT30TSE75X_BUS_FREE_TIME_TICKS);
if (i2c_read_regs(dev->i2c, dev->addr, reg, data, 2) <= 0) {
DEBUG("[at30tse75x] Can't read register 0x%x\n", reg);
i2c_release(dev->i2c);
return -1;
}
i2c_release(dev->i2c);
return 0;
}
static int at30tse75x_set_register(const at30tse75x_t *dev, uint8_t reg, uint16_t *data)
{
i2c_acquire(dev->i2c);
xtimer_spin(AT30TSE75X_BUS_FREE_TIME_TICKS);
if (i2c_write_regs(dev->i2c, dev->addr, reg, data, 2) <= 0) {
DEBUG("[at30tse75x] Can't write to register 0x%x\n", reg);
i2c_release(dev->i2c);
return -1;
}
i2c_release(dev->i2c);
return 0;
}
static int at30tse75x_reset(const at30tse75x_t *dev)
{
i2c_acquire(dev->i2c);
xtimer_spin(AT30TSE75X_BUS_FREE_TIME_TICKS);
if (i2c_write_byte(dev->i2c, 0x00, AT30TSE75X_CMD__GENERAL_CALL_RESET) != 1) {
i2c_release(dev->i2c);
return -1;
}
i2c_release(dev->i2c);
/* Wait for reset to complete */
xtimer_usleep(500);
return 0;
}
int at30tse75x_get_config(const at30tse75x_t *dev, uint8_t *data)
{
i2c_acquire(dev->i2c);
xtimer_spin(AT30TSE75X_BUS_FREE_TIME_TICKS);
if (i2c_read_reg(dev->i2c, dev->addr, AT30TSE75X_REG__CONFIG, data) <= 0) {
DEBUG("[at30tse75x] Can't read CONFIG register\n");
i2c_release(dev->i2c);
return -1;
}
i2c_release(dev->i2c);
return 0;
}
int at30tse75x_set_config(const at30tse75x_t *dev, uint8_t data)
{
i2c_acquire(dev->i2c);
xtimer_spin(AT30TSE75X_BUS_FREE_TIME_TICKS);
if (i2c_write_reg(dev->i2c, dev->addr, AT30TSE75X_REG__CONFIG, data) <= 0) {
DEBUG("[at30tse75x] Can't write to CONFIG register\n");
i2c_release(dev->i2c);
return -1;
}
i2c_release(dev->i2c);
return 0;
}
int at30tse75x_set_resolution(const at30tse75x_t *dev, at30tse75x_resolution_t resolution)
{
uint8_t config;
if(resolution < AT30TSE75X_RESOLUTION_9BIT ||
resolution > AT30TSE75X_RESOLUTION_12BIT) {
return -2;
}
if(at30tse75x_get_config(dev, &config) != 0) {
return -1;
}
config &= ~(AT30TSE75X_CONFIG__RESOLUTION_MASK);
config |= resolution << AT30TSE75X_CONFIG__RESOLUTION_SHIFT;
if(at30tse75x_set_config(dev, config) != 0) {
return -1;
}
return 0;
}
int at30tse75x_set_mode(const at30tse75x_t *dev, at30tse75x_mode_t mode)
{
uint8_t config;
if(at30tse75x_get_config(dev, &config) != 0) {
return -1;
}
switch(mode) {
case AT30TSE75X_MODE_ONE_SHOT:
config |= AT30TSE75X_CONFIG__SHUTDOWN_BIT;
/* Don't touch alarm mode */
break;
case AT30TSE75X_MODE_COMPARATOR:
config &= ~(AT30TSE75X_CONFIG__SHUTDOWN_BIT);
config &= ~(AT30TSE75X_CONFIG__ALARM_MODE_BIT);
break;
case AT30TSE75X_MODE_INTERRUPT:
config &= ~(AT30TSE75X_CONFIG__SHUTDOWN_BIT);
config |= AT30TSE75X_CONFIG__ALARM_MODE_BIT;
break;
default:
return -2;
}
if(at30tse75x_set_config(dev, config) != 0) {
return -1;
}
return 0;
}
int at30tse75x_set_alarm_polarity(const at30tse75x_t *dev, at30tse75x_alarm_polatity_t polarity)
{
uint8_t config;
if(at30tse75x_get_config(dev, &config) != 0) {
return -1;
}
switch(polarity) {
case AT30TSE75X_ALARM_ACTIVE_HIGH:
config |= AT30TSE75X_CONFIG__ALERT_POL_BIT;
break;
case AT30TSE75X_ALARM_ACTIVE_LOW:
config &= ~(AT30TSE75X_CONFIG__ALERT_POL_BIT);
break;
default:
return -2;
}
if(at30tse75x_set_config(dev, config) != 0) {
return -1;
}
return 0;
}
int at30tse75x_set_fault_tolerance(const at30tse75x_t *dev, at30tse75x_fault_tolerance_t tolerance)
{
if(tolerance < AT30TSE75X_ALARM_AFTER_1 ||
tolerance > AT30TSE75X_ALARM_AFTER_6) {
return -2;
}
uint8_t config;
if(at30tse75x_get_config(dev, &config) != 0) {
return -1;
}
config &= ~(AT30TSE75X_CONFIG__FTQ_MASK);
config |= tolerance << AT30TSE75X_CONFIG__FTQ_SHIFT;
if(at30tse75x_set_config(dev, config) != 0) {
return -1;
}
return 0;
}
int at30tse75x_set_limit_low(const at30tse75x_t *dev, int8_t t_low)
{
uint16_t tmp = (t_low << 8) | (0x00);
return at30tse75x_set_register(dev, AT30TSE75X_REG__LIMIT_LOW, &tmp);
}
int at30tse75x_set_limit_high(const at30tse75x_t *dev, int8_t t_high)
{
uint16_t tmp = (t_high << 8) | (0x00);
return at30tse75x_set_register(dev, AT30TSE75X_REG__LIMIT_HIGH, &tmp);
}
int at30tse75x_save_config(const at30tse75x_t *dev)
{
i2c_acquire(dev->i2c);
xtimer_spin(AT30TSE75X_BUS_FREE_TIME_TICKS);
if(i2c_write_byte(dev->i2c, dev->addr, AT30TSE75X_CMD__SAVE_TO_NVRAM) != 1) {
i2c_release(dev->i2c);
return -1;
}
i2c_release(dev->i2c);
/* Wait for copy to complete */
xtimer_usleep(5000);
return 0;
}
int at30tse75x_restore_config(const at30tse75x_t *dev)
{
i2c_acquire(dev->i2c);
xtimer_spin(AT30TSE75X_BUS_FREE_TIME_TICKS);
if(i2c_write_byte(dev->i2c, dev->addr, AT30TSE75X_CMD__RESTORE_FROM_NVRAM) != 1) {
i2c_release(dev->i2c);
return -1;
}
i2c_release(dev->i2c);
/* Wait for copy to complete */
xtimer_usleep(200);
return 0;
}
int at30tse75x_get_temperature(const at30tse75x_t *dev, float *temperature)
{
uint16_t tmp;
uint8_t config;
if(at30tse75x_get_config(dev, &config) != 0) {
return -1;
}
/* If sensor is shutdown trigger One-Shot mode*/
if(config & AT30TSE75X_CONFIG__SHUTDOWN_BIT) {
config |= AT30TSE75X_CONFIG__OS_BIT;
if(at30tse75x_set_config(dev, config) != 0) {
return -1;
}
/* Use resolution to calculate conversion time */
uint8_t resolution = (config & AT30TSE75X_CONFIG__RESOLUTION_MASK) >>
AT30TSE75X_CONFIG__RESOLUTION_SHIFT;
/* Wait until conversion is finished */
xtimer_usleep((uint32_t)(25000 << resolution));
}
/* Read temperature */
if(at30tse75x_get_register(dev, AT30TSE75X_REG__TEMPERATURE, &tmp) != 0) {
return -1;
}
/* Convert fixed point to float */
*temperature = temperature_to_float(tmp);
return 0;
}
int at30tse75x_init(at30tse75x_t *dev, i2c_t i2c, i2c_speed_t speed, uint8_t addr)
{
uint8_t config;
dev->i2c = i2c;
if( (addr < 0x48) || (addr > 0x4f) ) {
DEBUG("[at30tse75x] Invalid address\n");
return -2;
}
dev->addr = addr;
i2c_acquire(dev->i2c);
if(i2c_init_master(dev->i2c, speed) != 0) {
DEBUG("[at30tse75x] Can't initialize I2C master\n");
i2c_release(dev->i2c);
return -1;
}
i2c_release(dev->i2c);
/* Reset the device */
if(at30tse75x_reset(dev) != 0) {
return -1;
}
/* Poll the device, fail if unavailable */
if(at30tse75x_get_config(dev, &config) != 0) {
return -1;
}
DEBUG("[at30tse75x] Config: 0x%x\n", config);
return 0;
}