RIOT-OS/RIOT
RIOT-OS/RIOT
1
0
Fork 0
mirror of https://github.com/RIOT-OS/RIOT.git synced 2024-12-29 04:50:03 +01:00
Code Releases Activity
1d34522703
RIOT/drivers/lm75a/lm75a-temp-sensor.c
Ludwig Ortmann 2525920426 remove trailing whitespace and newlines
2014-02-11 18:45:06 +01:00

320 lines
8.8 KiB
C
Raw Blame History

/*
* lm75a-temp-sensor.c - Driver for the LM75A temperature sensor based on the
* i2c interface.
*
* Copyright (C) 2013 Zakaria Kasmi <zkasmi@inf.fu-berlin.de>
*
* This source code is licensed under the LGPLv2 license,
* See the file LICENSE for more details.
*
*/
/**
* @file
* @internal
* @brief Driver for the LM75A temperature sensor.
* The communication between the LM75A and the MCU is
* based on the i2c interface.
*
* @author Freie Universität Berlin, Computer Systems & Telematics
* @author Zakaria Kasmi <zkasmi@inf.fu-berlin.de>
* @version $Revision: 3855 $
*
* @note $Id: lm75a-temp-sensor.c 3855 2013-09-05 13:53:49 kasmi $
*/
#include <stdlib.h>
#include <limits.h>
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <math.h>
#include "msg.h"
#include "thread.h"
#include "vtimer.h"
#include "timex.h"
#include "lpc2387.h"
#include "gpioint.h"
#include "i2c.h"
#include "lm75a-temp-sensor.h"
#include "hwtimer.h"
#include "board.h"
//declaration as volatile is important, otherwise no interrupt is triggered.
volatile bool my_alarm = false;
static uint16_t get_2s_complement(uint16_t num)
{
return ~(num) + 1;
}
//Write: MC --> Sensor
static void to_bytes(float_t f, uint8_t *buff)
{
int32_t i = (int32_t)(f * 2);
buff[0] = (uint8_t)((i >> LM75A_BIT1) & 0xFF);//Most signif. byte
buff[1] = (uint8_t)((i & LM75A_BIT1) << LM75A_BIT7);//Least signif. byte
}
static uint16_t to_uint16(uint8_t *buff)
{
if (buff != NULL) {
return (buff[0] << LM75A_BIT8) | buff[1];
}
else {
return UINT16_MAX;
}
}
//Read: Sensor --> MC
volatile static float_t to_float(uint8_t reg_addr, uint16_t reg_value)
{
uint16_t sign = reg_value & LM75A_SIGN_BIT_MASK;
float_t f_temp = 0.0;
float_t factor = 0.0;
switch (reg_addr) {
case LM75A_OVER_TEMP_REG:
case LM75A_THYST_REG:
factor = 0.5;
break;
case LM75A_TEMPERATURE_REG:
factor = 0.125;
}
if (sign) { //the number is negative
f_temp = (get_2s_complement(reg_value) & LM75A_DATA_BITS_MASK)
* -factor;
}
else { //the number is positive
f_temp = reg_value * factor;
}
return f_temp;
}
static void set_register(uint8_t i2c_interface, uint8_t reg_addr, float_t value)
{
bool status = false;
uint8_t tx_buff[2];
switch (reg_addr) {
case LM75A_OVER_TEMP_REG:
case LM75A_THYST_REG:
to_bytes(value, tx_buff);
status = i2c_write(i2c_interface, LM75A_ADDR, reg_addr, tx_buff, 2);
break;
case LM75A_CONFIG_REG:
tx_buff[0] = (uint8_t) value;
status = i2c_write(i2c_interface, LM75A_ADDR, reg_addr, tx_buff, 1);
}
if (!status) {
puts(
"[lm75a_tempSensorI2C/lm75A_setRegister]: Slave is not ready !!\n");
}
}
void lm75A_set_over_temperature(float_t tos)
{
set_register(LM75A_I2C_INTERFACE, LM75A_OVER_TEMP_REG, tos);
}
void lm75A_set_hysteresis_temperature(float_t thsyt)
{
set_register(LM75A_I2C_INTERFACE, LM75A_THYST_REG, thsyt);
}
static uint16_t lm75A_get_register_value(uint8_t i2c_interface,
uint8_t reg_addr,
uint8_t reg_size)
{
bool status = false;
uint8_t rx_buff[reg_size];
i2c_clear_buffer(rx_buff, reg_size);
if ((reg_size > 0) && (reg_size < 3)) {
status = i2c_read(i2c_interface, LM75A_ADDR, reg_addr, rx_buff,
reg_size);
if (!status) { //Slave is not ready
puts(
"[lm75a_tempSensorI2C/lm75A_getConfigReg]: Slave is not\
ready !\n");
if (reg_size < 2) {
return UCHAR_MAX;
}
else {
return UINT16_MAX;
}
}
else { //Slave acknowledged
if (reg_size < 2) {
return rx_buff[0];
}
else {
return to_uint16(rx_buff);
}
}
}
else {
puts("the register size must be less than 2");
return UINT16_MAX;
}
}
uint8_t lm75A_get_config_reg(void)
{
return lm75A_get_register_value(LM75A_I2C_INTERFACE, LM75A_CONFIG_REG, 1);
}
float_t lm75A_get_hysteresis_temperature(void)
{
uint16_t hyst_reg_value = 0;
hyst_reg_value = lm75A_get_register_value(LM75A_I2C_INTERFACE,
LM75A_THYST_REG, 2);
hyst_reg_value = (hyst_reg_value >> LM75A_BIT7);
return to_float(LM75A_THYST_REG, hyst_reg_value);
}
float_t lm75A_get_over_temperature(void)
{
uint16_t over_temp = 0;
over_temp = lm75A_get_register_value(LM75A_I2C_INTERFACE,
LM75A_OVER_TEMP_REG, 2);
over_temp = (over_temp >> LM75A_BIT7);
return to_float(LM75A_OVER_TEMP_REG, over_temp);
}
float_t lm75A_get_ambient_temperature(void)
{
uint16_t amb_temp = 0;
amb_temp = lm75A_get_register_value(LM75A_I2C_INTERFACE,
LM75A_TEMPERATURE_REG, 2);
amb_temp = (amb_temp >> LM75A_BIT5);
return to_float(LM75A_TEMPERATURE_REG, amb_temp);
}
void lm75A_reset(void)
{
lm75A_set_over_temperature(LM75A_DEFAULT_TOS);
lm75A_set_hysteresis_temperature(LM75A_DEFAULT_THYST);
set_register(LM75A_I2C_INTERFACE, LM75A_CONFIG_REG,
LM75A_DEFAULT_CONFIG_VALUE);
}
void lm75A_set_operation_mode(uint8_t op_mode)
{
uint8_t config_reg = lm75A_get_config_reg();
switch (op_mode) {
case LM75A_NORMAL_OPERATION_MODE:
config_reg &= ~(1 << LM75A_BIT0);
break;
case LM75A_SHUTDOWN_MODE:
config_reg |= (1 << LM75A_BIT0);
break;
case LM75A_COMPARATOR_MODE:
config_reg &= ~(1 << LM75A_BIT1);
break;
case LM75A_INTERRUPT_MODE:
config_reg |= (1 << LM75A_BIT1);
break;
default:
config_reg &= ~(1 << LM75A_BIT0);
}
set_register(LM75A_I2C_INTERFACE, LM75A_CONFIG_REG, config_reg);
}
bool lm75A_ext_irq_handler_register(int32_t port, uint32_t pin_bit_mask,
int32_t flags, void *handler)
{
return gpioint_set(port, pin_bit_mask, flags, handler);
}
bool lm75A_init(uint8_t i2c_interface, uint32_t baud_rate,
void *external_interr_handler)
{
if (i2c_initialize(i2c_interface, (uint32_t) I2CMASTER, 0, baud_rate, NULL)
== false) { /* initialize I2C */
puts("fatal error happened in i2c_initialize()\n");
return false;
}
//i2c_enable_pull_up_resistor(i2c_interface);
i2c_disable_pull_up_resistor(i2c_interface);
if ((external_interr_handler != NULL)
&& lm75A_ext_irq_handler_register(2, BIT3, GPIOINT_FALLING_EDGE,
external_interr_handler)) {
printf("# %-70s%10s\n", "External interrupt handler registration",
"...[OK]");
}
else {
printf("# %-70s%10s\n", "External interrupt handler registration",
"...[FAILED]");
return false;
}
puts("################## Before reset ##################");
printf("configReg = %u\n", lm75A_get_config_reg());
printf("hystTemp = %f\n", lm75A_get_hysteresis_temperature());
printf("overTemp = %f\n", lm75A_get_over_temperature());
lm75A_reset();
puts("\n################## After reset ##################");
printf("configRegInitial = %u\n", lm75A_get_config_reg());
printf("initialHystTemp = %f\n", lm75A_get_hysteresis_temperature());
printf("initialOverTemp = %f\n", lm75A_get_over_temperature());
puts("\n################## New configuration ##################");
// set the hysteresis temperature
lm75A_set_hysteresis_temperature(32.0);
printf("hystTemp = %f\n", lm75A_get_hysteresis_temperature());
lm75A_set_over_temperature(33.0);
printf("overTemp = %f\n", lm75A_get_over_temperature());
puts("\n################## Go to comparator mode ##################");
lm75A_set_operation_mode(LM75A_COMPARATOR_MODE);
printf("configReg = %u\n", lm75A_get_config_reg());
// puts("\n################## Go to interrupt mode ##################");
// lm75A_set_operation_mode(LM75A_INTERRUPT_MODE);
// printf("configReg = %u\n", lm75A_get_config_reg());
return true;
}
void lm75A_set_in_alarm(bool b)
{
my_alarm = b;
}
/*
* Application entry point.
*/
void lm75A_start_sensor_sampling(void (*handler)(void))
{
/*
* Normal main() thread activity.
*/
while (true) {
//Toggle the green LED;
LED_RED_TOGGLE;
printf("amb_temp = %3.3f\n", lm75A_get_ambient_temperature());
if (my_alarm && (handler != NULL)) {
LED_GREEN_ON;
handler();
my_alarm = false;
}
hwtimer_wait(HWTIMER_TICKS(100000));
LED_RED_TOGGLE;
hwtimer_wait(HWTIMER_TICKS(100000));
}
}
View Git Blame Copy Permalink