Can someone tell me what is the error in my code? (DHT11, STM32F429i-disc1)

[CMart.2]

I have the STM32F4291-disc1 microcontroller and the dht11 sensor that measures temperature and humidity. I'm trying to get the sensor to work, but I don't want the data (Temperature and humidity) on the screen and I don't know what could be wrong. My main.c code is as follows:

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2020 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under Ultimate Liberty license
  * SLA0044, the "License"; You may not use this file except in compliance with
  * the License. You may obtain a copy of the License at:
  *                             www.st.com/SLA0044
  *
  ******************************************************************************
  */
/* USER CODE END Header */
 
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "cmsis_os.h"
#include "usb_host.h"
 
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "i2c-lcd.h"
#include "stdio.h"
/* USER CODE END Includes */
 
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
 
/* USER CODE END PTD */
 
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
 
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
 
/* USER CODE END PM */
 
/* Private variables ---------------------------------------------------------*/
CRC_HandleTypeDef hcrc;
 
DMA2D_HandleTypeDef hdma2d;
 
I2C_HandleTypeDef hi2c3;
 
LTDC_HandleTypeDef hltdc;
 
SPI_HandleTypeDef hspi5;
 
TIM_HandleTypeDef htim1;
TIM_HandleTypeDef htim6;
 
UART_HandleTypeDef huart1;
 
SDRAM_HandleTypeDef hsdram1;
 
osThreadId defaultTaskHandle;
/* USER CODE BEGIN PV */
 
/* USER CODE END PV */
 
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_CRC_Init(void);
static void MX_DMA2D_Init(void);
static void MX_FMC_Init(void);
static void MX_I2C3_Init(void);
static void MX_LTDC_Init(void);
static void MX_SPI5_Init(void);
static void MX_TIM1_Init(void);
static void MX_USART1_UART_Init(void);
static void MX_TIM6_Init(void);
void StartDefaultTask(void const * argument);
 
/* USER CODE BEGIN PFP */
 
/* USER CODE END PFP */
 
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
void delay (uint16_t time)
{
	/* change your code here for the delay in microseconds */
	__HAL_TIM_SET_COUNTER(&htim6, 0);
	while ((__HAL_TIM_GET_COUNTER(&htim6))<time);
}
 
void Display_Temp (float Temp)
{
	char str[20] = {0};
	lcd_put_cur(0, 0);
 
	sprintf (str, "TEMP:- %.2f ", Temp);
	lcd_send_string(str);
	lcd_send_data('C');
}
 
void Display_Rh (float Rh)
{
	char str[20] = {0};
	lcd_put_cur(1, 0);
 
	sprintf (str, "RH:- %.2f ", Rh);
	lcd_send_string(str);
	lcd_send_data('%');
}
 
uint8_t Rh_byte1, Rh_byte2, Temp_byte1, Temp_byte2;
uint16_t SUM, RH, TEMP;
 
float Temperature = 0;
float Humidity = 0;
uint8_t Presence = 0;
 
void Set_Pin_Output (GPIO_TypeDef *GPIOx, uint16_t GPIO_Pin)
{
	GPIO_InitTypeDef GPIO_InitStruct = {0};
	GPIO_InitStruct.Pin = GPIO_Pin;
	GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
	GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
	HAL_GPIO_Init(GPIOx, &GPIO_InitStruct);
}
 
void Set_Pin_Input (GPIO_TypeDef *GPIOx, uint16_t GPIO_Pin)
{
	GPIO_InitTypeDef GPIO_InitStruct = {0};
	GPIO_InitStruct.Pin = GPIO_Pin;
	GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
	GPIO_InitStruct.Pull = GPIO_PULLUP;
	HAL_GPIO_Init(GPIOx, &GPIO_InitStruct);
}
 
#define DHT11_PORT GPIOC
#define DHT11_PIN GPIO_PIN_3
 
void DHT11_Start (void)
{
	Set_Pin_Output (DHT11_PORT, DHT11_PIN);  // set the pin as output
	HAL_GPIO_WritePin (DHT11_PORT, DHT11_PIN, 0);   // pull the pin low
	delay (18000);   // wait for 18ms
    HAL_GPIO_WritePin (DHT11_PORT, DHT11_PIN, 1);   // pull the pin high
	delay (20);   // wait for 20us
	Set_Pin_Input(DHT11_PORT, DHT11_PIN);    // set as input
}
 
uint8_t DHT11_Check_Response (void)
{
	uint8_t Response = 0;
	delay (40);
	if (!(HAL_GPIO_ReadPin (DHT11_PORT, DHT11_PIN)))
	{
		delay (80);
		if ((HAL_GPIO_ReadPin (DHT11_PORT, DHT11_PIN))) Response = 1;
		else Response = -1; // 255
	}
	while ((HAL_GPIO_ReadPin (DHT11_PORT, DHT11_PIN)));   // wait for the pin to go low
 
	return Response;
}
 
uint8_t DHT11_Read (void)
{
	uint8_t i,j;
	for (j=0;j<8;j++)
	{
		while (!(HAL_GPIO_ReadPin (DHT11_PORT, DHT11_PIN)));   // wait for the pin to go high
		delay (40);   // wait for 40 us
		if (!(HAL_GPIO_ReadPin (DHT11_PORT, DHT11_PIN)))   // if the pin is low
		{
			i&= ~(1<<(7-j));   // write 0
		}
		else i|= (1<<(7-j));  // if the pin is high, write 1
		while ((HAL_GPIO_ReadPin (DHT11_PORT, DHT11_PIN)));  // wait for the pin to go low
	}
	return i;
}
/* USER CODE END 0 */
 
/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
  /* USER CODE BEGIN 1 */
 
  /* USER CODE END 1 */
 
  /* MCU Configuration--------------------------------------------------------*/
 
  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();
 
  /* USER CODE BEGIN Init */
 
  /* USER CODE END Init */
 
  /* Configure the system clock */
  SystemClock_Config();
 
  /* USER CODE BEGIN SysInit */
 
  /* USER CODE END SysInit */
 
  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_CRC_Init();
  MX_DMA2D_Init();
  MX_FMC_Init();
  MX_I2C3_Init();
  MX_LTDC_Init();
  MX_SPI5_Init();
  MX_TIM1_Init();
  MX_USART1_UART_Init();
  MX_TIM6_Init();
  /* USER CODE BEGIN 2 */
  HAL_TIM_Base_Start(&htim6);
 
  lcd_init();
  lcd_send_string("INITIALISING>>>>");
  HAL_Delay(2000);
  lcd_clear ();
  /* USER CODE END 2 */
 
  /* USER CODE BEGIN RTOS_MUTEX */
  /* add mutexes, ... */
  /* USER CODE END RTOS_MUTEX */
 
  /* USER CODE BEGIN RTOS_SEMAPHORES */
  /* add semaphores, ... */
  /* USER CODE END RTOS_SEMAPHORES */
 
  /* USER CODE BEGIN RTOS_TIMERS */
  /* start timers, add new ones, ... */
  /* USER CODE END RTOS_TIMERS */
 
  /* USER CODE BEGIN RTOS_QUEUES */
  /* add queues, ... */
  /* USER CODE END RTOS_QUEUES */
 
  /* Create the thread(s) */
  /* definition and creation of defaultTask */
  osThreadDef(defaultTask, StartDefaultTask, osPriorityNormal, 0, 4096);
  defaultTaskHandle = osThreadCreate(osThread(defaultTask), NULL);
 
  /* USER CODE BEGIN RTOS_THREADS */
  /* add threads, ... */
  /* USER CODE END RTOS_THREADS */
 
  /* Start scheduler */
  osKernelStart();
 
  /* We should never get here as control is now taken by the scheduler */
  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */
 
    /* USER CODE BEGIN 3 */
	  Display_Temp(Temperature);
	  Display_Rh(Humidity);
 
	  DHT11_Start();
	  	  Presence = DHT11_Check_Response();
	  	  Rh_byte1 = DHT11_Read ();
	  	  Rh_byte2 = DHT11_Read ();
	  	  Temp_byte1 = DHT11_Read ();
	  	  Temp_byte2 = DHT11_Read ();
	  	  SUM = DHT11_Read();
 
	  	  TEMP = Temp_byte1;
	  	  RH = Rh_byte1;
 
	  	  Temperature = (float) TEMP;
	  	  Humidity = (float) RH;
  }
  /* USER CODE END 3 */
}

[CMart.2]

There is no FREERTOS on f407, but i don't understand what solution you say i can give it.

[CMart.2]

So the solution is to transfer the code that I want to be executed here?

[rromano001]

Both yes and NO.

Yes say code is executed but under strict control of os executive

Also if just one task is active get preempted and critical timing got broken.

>One task is no guarantee another task start in the middle of a task so preemption and scheduling is active also with one task.

Due to preemption answer is also NO, code start be executed but don't expect timing correct. May be but just add one or more tasks stop working and hang due to timeout missing on code.

Usage of HTxx protocol under OSes need use some sort of automated reading/writing.

Dallas OneWire can be simulated on USART and DMA, I wrote a device driver use STM single wire in full duplex and is fine under FREERTOS.

DHTxxx protocol is different and require constant sampling without pulses so USART mode get useless. Timer direct mode can solve but result in a big challenge to read a "Hobby grade" unreliable and expensive sensor.

Why you enabled FREERTOS I see just one task exists and no multitasks seems necessary?

Regards