I am trying to read a DS18B20 temperature sensor with I2C. I use a DS2484 driver to convert the I2C signals to a 1-Wire signal.
I have the following code:
/* Includes ------------------------------------------------------------------*/
#include "stm32l1xx_hal.h"
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Private variables ---------------------------------------------------------*/
I2C_HandleTypeDef hi2c2;
RTC_HandleTypeDef hrtc;
/* USER CODE BEGIN PV */
/* Private variables ---------------------------------------------------------*/
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_I2C2_Init(void);
static void MX_RTC_Init(void);
/* USER CODE BEGIN PFP */
/* Private function prototypes -----------------------------------------------*/
void ow_setup_ds2484(void);
/* USER CODE END PFP */
/* USER CODE BEGIN 0 */
// I2C test
// uint8_t dummy_data[2] = {0};
// HAL_I2C_Master_Transmit (&hi2c2, 0x10, &dummy_data[0], 2, 1000); // 1sec timeout
uint8_t byte_array[6];
byte_array[0] = 0xE1; /* Data 0 */
byte_array[1] = 0xC3; /* Data 1 */
byte_array[2] = 0xD2; /* Data 2 */
byte_array[3] = 0xEE; /* Data 3 */
// byte_array[4] = 0x00; /* Data 4 */
uint8_t dummy_data[25] =
{0xF0, // reset
0x01, //byte om data mee in te kunnen lezen
0xD2,//WCFG
0x22};
uint8_t dummy_data1[25] =
{
0x22};
HAL_I2C_Master_Transmit (&hi2c2, 0x30, &dummy_data[0], 1, 1000); // reset device
HAL_I2C_Master_Receive(&hi2c2, 0x31, &dummy_data[1] , 1, 1000); // lees byte in na reset
HAL_I2C_Master_Transmit (&hi2c2, 0x30, byte_array, 2, 1000); // set read pointer
HAL_I2C_Master_Transmit (&hi2c2, 0x30, &dummy_data[2], 1, 1000); // configureer
HAL_I2C_Master_Receive(&hi2c2, 0x31, &dummy_data[1] , 1, 1000); // lees byte in na configureren
/* USER CODE END 0 */
int main(void)
{
/
HAL_Init();
/* Configure the system clock */
SystemClock_Config();
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_I2C2_Init();
MX_RTC_Init();
ow_setup_ds2484();
/* USER CODE BEGIN 2 */
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
// --- toggle PC4 ---//
HAL_GPIO_WritePin (GPIOC,GPIO_PIN_9,GPIO_PIN_SET); // enable pin (vcc)
HAL_Delay (100);
HAL_GPIO_WritePin (GPIOC,GPIO_PIN_9,GPIO_PIN_RESET); // disable pin (0v)
HAL_Delay (100);
} // while
} // main
void ow_setup_ds2484(void)
{
}
I followed the explanation of the datasheet:
Device Reset (After Power-Up)
S AD,0 A DRST A Sr AD,1 A A\ P
Activities that are underlined denote an optional read access to verify the success of the command.
Set Read Pointer (To Read from Another Register)
Case A: Valid Read Pointer Code
S AD,0 A SRP A C3h A P
C3h is the read pointer code for the Device Configuration register.
Case B: Invalid Read Pointer Code
S AD,0 A SRP A E5h A\ P
E5h is an invalid read pointer code.
Write Device Configuration (Before Starting 1-Wire Activity)
Case A: 1-Wire Idle (1WB = 0)
S AD,0 A WCFG A A Sr AD,1 A A\ P
Activities that are underlined denote an optional read access to verify the success of the command.
Case B: 1-Wire Busy (1WB = 1)
S AD,0 A WCFG A\ P
The master should stop and restart as soon as the DS2484 does not acknowledge the command code.
Adjust 1-Wire Port (after power-up, e.g., to select a 1-Wire timing other than the default)
Case A: 1-Wire Idle (1WB = 0)
Repeat to set additional port parameters
S AD,0 A ADJP A A A P
However, I still don’t know what to do next to read the DS18B20 sensor. Plese help me 