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add improvement from thermo-regulator project

This commit is contained in:
King Kévin 2017-03-28 12:37:34 +02:00
parent bdcfd4f54b
commit b7049df659
2 changed files with 6 additions and 7 deletions
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11
lib/sensor_dht11.c
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@ -16,12 +16,11 @@
* @file sensor_dht11.c
* @author King Kévin <kingkevin@cuvoodoo.info>
* @date 2017
* @note peripherals used: GPIO and timer @ref sensor_dht11_timer
* @note peripherals used: timer channel @ref sensor_dht11_timer
*/
/* standard libraries */
#include <stdint.h> // standard integer types
#include <stdlib.h> // general utilities
/* STM32 (including CM3) libraries */
#include <libopencmsis/core_cm3.h> // Cortex M3 utilities
@ -44,7 +43,7 @@
volatile bool sensor_dht11_measurement_received = false;
/** communication state */
/** communication states */
volatile enum sensor_dht11_state_t {
SENSOR_DHT11_OFF, // no request has started
SENSOR_DHT11_HOST_START, // host starts request (and waits >18ms)
@ -52,7 +51,7 @@ volatile enum sensor_dht11_state_t {
SENSOR_DHT11_SLAVE_START, // slave responds to request and puts signal low for 80 us and high for 80 us
SENSOR_DHT11_SLAVE_BIT, // slave is sending bit by putting signal low for 50 us and high (26-28 us = 0, 70 us = 1)
SENSOR_DHT11_MAX
} sensor_dht11_state = SENSOR_DHT11_OFF;
} sensor_dht11_state = SENSOR_DHT11_OFF; /**< current communication state */
/** the bit number being sent (MSb first), up to 40 */
volatile uint8_t sensor_dht11_bit = 0;
@ -106,7 +105,7 @@ bool sensor_dht11_measurement_request(void)
if (gpio_get(TIM_CH_PORT(SENSOR_DHT11_TIMER,SENSOR_DHT11_CHANNEL), TIM_CH_PIN(SENSOR_DHT11_TIMER,SENSOR_DHT11_CHANNEL))==0) { // signal should be high per default
return false;
}
if (TIM_CR1(SENSOR_DHT11_TIMER)&(TIM_CR1_CEN)) { // timer should be off
if (TIM_CR1(TIM(SENSOR_DHT11_TIMER))&(TIM_CR1_CEN)) { // timer should be off
return false;
}
sensor_dht11_reset(); // reset states
@ -126,7 +125,7 @@ struct sensor_dht11_measurement_t sensor_dht11_measurement_decode(void)
if (sensor_dht11_bit<40) { // not enough bits received
return measurement;
}
if (sensor_dht11_bits[0]+sensor_dht11_bits[1]+sensor_dht11_bits[2]+sensor_dht11_bits[3]!=sensor_dht11_bits[4]) { // error in checksum (not really parity bit, as mentioned in the datasheet)
if ((uint8_t)(sensor_dht11_bits[0]+sensor_dht11_bits[1]+sensor_dht11_bits[2]+sensor_dht11_bits[3])!=sensor_dht11_bits[4]) { // error in checksum (not really parity bit, as mentioned in the datasheet)
return measurement;
}
// calculate measured values (byte 1 and 3 should be the factional value but they are always 0)

2
lib/sensor_dht11.h
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@ -16,7 +16,7 @@
* @file sensor_dht11.h
* @author King Kévin <kingkevin@cuvoodoo.info>
* @date 2017
* @note peripherals used: GPIO @ref sensor_dht11_gpio, timer @ref sensor_dht11_timer
* @note peripherals used: timer channel @ref sensor_dht11_timer (add external pull-up resistor)
*/
#pragma once