[DHT11] add working driver

This commit is contained in:
ІО-23 Шмуляр Олег 2025-05-06 16:13:24 +03:00
parent bf83a6c0eb
commit 53c2820cc4
4 changed files with 150 additions and 7 deletions

18
Core/Inc/DHT11.h Normal file
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@ -0,0 +1,18 @@
#ifndef __DHT11
#define __DHT11
#define SKIP_LOW while (!(GPIOD->IDR & 0x0800)) {}
#define SKIP_HIGH while (GPIOD->IDR & 0x0800) {}
__attribute__((packed))
struct DHT11_Data {
uint8_t humid_integral;
uint8_t humid_decimal;
uint8_t temp_integral;
uint8_t temp_decimal;
uint8_t crc;
};
int DHT11_run_test(void);
#endif

113
Core/Src/DHT11.c Normal file
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@ -0,0 +1,113 @@
#include "main.h"
#include "generic_macros.h"
#include "lcd.h"
#include "DHT11.h"
extern TIM_HandleTypeDef htim2;
static inline void wait(uint32_t wait_us)
{
uint32_t target_time = TIM2->CNT;
target_time += wait_us << 4;
while (TIM2->CNT < target_time) {}
}
static inline size_t dht11_measure_high_duration(void)
{
SKIP_LOW;
uint32_t start_time = TIM2->CNT;
SKIP_HIGH;
uint32_t end_time = TIM2->CNT;
// elapsed_time > 49us ? 1 : 0
return (end_time - start_time) > (49 << 4);
}
static size_t dht11_read_value(struct DHT11_Data *data)
{
// treat data as a normal array to simplify read loop
uint8_t *buffer = (uint8_t *) data;
register uint32_t read_register = 0;
TIM2->CNT = 0;
HAL_TIM_Base_Start(&htim2);
GPIOD->MODER |= 0x00400000; // enable output mode on GPIOD 11
GPIOD->BSRR = GPIO_PIN_11; // enable DHT11
wait(50000); // hold HIGH for 50 ms
GPIOD->BSRR = GPIO_PIN_11 << 16; // start signal
wait(30000); // hold it for 30 ms
GPIOD->BSRR = GPIO_PIN_11; // pull up, DHT will now take control over the connection
wait(100);
GPIOD->MODER &= 0xFF3FFFFF; // switch GPIOD 11 to input mode
// reading pull down from DHT11
SKIP_LOW;
// waiting for 500ms max
for (size_t i = TIM2->CNT + (500000 << 4); TIM2->CNT <= i; )
if (!(GPIOD->IDR & 0x0800))
goto reading_data;
// if didn't exit through goto, then DHT11 awaiting has timed out
return 1;
reading_data:
// read 5 bytes of data
for (size_t i = 0; i < 5; i++) {
for (register size_t j = 0; j < 8; j++) {
read_register <<= 1;
read_register |= dht11_measure_high_duration();
}
buffer[i] = (uint8_t) read_register;
}
HAL_TIM_Base_Stop(&htim2);
return 0;
}
int DHT11_run_test(void)
{
DISPLAY_CLEAR;
display_write_data_seq("DHT11 Temp+Humid");
struct DHT11_Data data;
size_t result = dht11_read_value(&data);
size_t checksum_mismatch = ((
data.humid_decimal
+ data.humid_integral
+ data.temp_decimal
+ data.temp_integral
) & 0xFF) != data.crc;
if (result) {
DISPLAY_SET_CURSOR(1, 4);
display_write_data_seq("StartTimeout");
} else if (checksum_mismatch) {
DISPLAY_SET_CURSOR(1, 4);
display_write_data_seq("CRC Fault");
} else {
DISPLAY_SET_CURSOR(1, 4);
display_write_data_seq("OK");
DISPLAY_SET_CURSOR(1, 7);
display_write_data_byte('0' + (data.humid_integral/10)%10);
display_write_data_byte('0' + (data.humid_integral)%10);
display_write_data_seq("% ");
display_write_data_byte('0' + (data.temp_integral/10)%10);
display_write_data_byte('0' + (data.temp_integral)%10);
display_write_data_byte('.');
display_write_data_byte('0' + data.temp_decimal);
display_write_data_seq("C");
}
return (result || checksum_mismatch);
}

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@ -32,6 +32,7 @@
#include "LIS302DL.h"
#include "MP45DT02.h"
#include "LSM9DS1.h"
#include "DHT11.h"
/* USER CODE END Includes */
@ -75,10 +76,10 @@ SPI_HandleTypeDef hspi1;
TIM_HandleTypeDef htim2;
extern size_t display_current_frame;
/* USER CODE BEGIN PV */
extern size_t display_current_frame;
static const int ((*executors[])(void)) = {
DNI_show_celsius,
PCA9685_run_test,
@ -88,7 +89,8 @@ static const int ((*executors[])(void)) = {
LIS302DL_run_test,
MP45DT02_run_test,
LSM9DS1_test_accel,
LSM9DS1_test_magnet
LSM9DS1_test_magnet,
DHT11_run_test
};
static const void ((*cleanup_functions[])(void)) = {
@ -100,6 +102,7 @@ static const void ((*cleanup_functions[])(void)) = {
NULL,
NULL,
LSM9DS1_cleanup_accel,
NULL,
NULL
};
@ -568,10 +571,17 @@ static void MX_GPIO_Init(void)
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOE, &GPIO_InitStruct);
/*Configure GPIO pins : PD11 PD12 PD13 PD14
PD15 PD4 PD7 */
GPIO_InitStruct.Pin = GPIO_PIN_11|GPIO_PIN_12|GPIO_PIN_13|GPIO_PIN_14
|GPIO_PIN_15|GPIO_PIN_4|GPIO_PIN_7;
/*Configure GPIO pin : PD11 */
GPIO_InitStruct.Pin = GPIO_PIN_11;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);
/*Configure GPIO pins : PD12 PD13 PD14 PD15
PD4 PD7 */
GPIO_InitStruct.Pin = GPIO_PIN_12|GPIO_PIN_13|GPIO_PIN_14|GPIO_PIN_15
|GPIO_PIN_4|GPIO_PIN_7;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;

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@ -121,6 +121,8 @@ PC8.Locked=true
PC8.Signal=GPIO_Input
PC9.Locked=true
PC9.Signal=GPIO_Input
PD11.GPIOParameters=GPIO_Speed
PD11.GPIO_Speed=GPIO_SPEED_FREQ_VERY_HIGH
PD11.Locked=true
PD11.Signal=GPIO_Output
PD12.Locked=true