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WIP SHT4x

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This commit is contained in:
dooku 2021-06-08 14:56:57 +02:00
parent 22612f63e4
commit dc7f86f5af
4 changed files with 142 additions and 2 deletions
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1
fw/Core/Inc/main.h
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@ -49,6 +49,7 @@ extern "C" {
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "led.h"
#include "sht4x.h"
/* USER CODE END Includes */
/* Exported types ------------------------------------------------------------*/

51
fw/Core/Inc/sht4x.h Normal file
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@ -0,0 +1,51 @@
/*
* sht4x.h
*
* Created on: Jun 8, 2021
* Author: user
*/
#ifndef INC_SHT4X_H_
#define INC_SHT4X_H_
#include "stdint.h"
#include "stm32l0xx_ll_i2c.h"
/*
* Defines & macros
*/
#define SHT4X_I2C_ADDRESS 0x44
/*
* Data types
*/
typedef struct {
I2C_TypeDef *i2c;
} sht4x_context_t;
typedef enum {
START_MEAS_HIGH_PRECISION = 0xFD,
START_MEAS_MEDIUM_PRECISION = 0xF6,
START_MEAS_LOW_PRECISION = 0xE0,
READ_SERIAL = 0x89,
SOFT_RESET = 0x94,
HEATER_200_mW_1_s = 0x39,
HEATER_200_mW_01_s = 0x32,
HEATER_110_mW_1_s = 0x2F,
HEATER_110_mW_01_s = 0x24,
HEATER_20_mW_1_s = 0x1E,
HEATER_20_mW_01_s = 0x15
} sht4x_cmd_t;
/*
* Function prototypes
*/
int sht4x_init(sht4x_context_t *context);
int sht4x_send_cmd(sht4x_cmd_t cmd);
int sht4x_read_data(uint8_t *buffer, int len);
int sht4x_measure(int *temperature, int *relative_humidity);
#endif /* INC_SHT4X_H_ */

9
fw/Core/Src/main.c
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@ -108,14 +108,20 @@ int main(void)
led_context.blue_led_pin = LED_B_Pin;
led_init(&led_context, 50, 1000);
led_set_color(80, 0, 0);
/* SHT4x context init */
sht4x_context_t sht4x_context;
sht4x_context.i2c = I2C1;
sht4x_init(&sht4x_context);
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
int T, RH;
sht4x_measure(&T, &RH);
while (1)
{
/* USER CODE END WHILE */
led_pwm_handler(); // TODO temporary, should be placed in timer interrupt (SysTick)
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
@ -218,7 +224,6 @@ static void MX_I2C1_Init(void)
LL_I2C_Init(I2C1, &I2C_InitStruct);
LL_I2C_SetOwnAddress2(I2C1, 0, LL_I2C_OWNADDRESS2_NOMASK);
/* USER CODE BEGIN I2C1_Init 2 */
/* USER CODE END I2C1_Init 2 */
}

83
fw/Core/Src/sht4x.c Normal file
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@ -0,0 +1,83 @@
/*
* sht4x.c
*
* Created on: Jun 8, 2021
* Author: user
*/
#include "sht4x.h"
sht4x_context_t *sht4x_context;
int sht4x_init(sht4x_context_t *context)
{
sht4x_context = context;
}
void i2c_transmit(uint8_t address, uint8_t *buffer, int len)
{
LL_I2C_HandleTransfer(sht4x_context->i2c, address, LL_I2C_ADDRESSING_MODE_7BIT, len,
LL_I2C_MODE_AUTOEND, LL_I2C_GENERATE_START_WRITE);
int i = 0;
while (!LL_I2C_IsActiveFlag_STOP(sht4x_context->i2c)) {
if (LL_I2C_IsActiveFlag_TXE(sht4x_context->i2c)) {
if (i < len) {
LL_I2C_TransmitData8(sht4x_context->i2c, buffer[i++]);
}
}
}
LL_I2C_ClearFlag_STOP(sht4x_context->i2c);
}
void i2c_receive(uint8_t address, uint8_t *buffer, int len)
{
LL_I2C_HandleTransfer(sht4x_context->i2c, address, LL_I2C_ADDRESSING_MODE_7BIT, len,
LL_I2C_MODE_AUTOEND, LL_I2C_GENERATE_START_READ);
int i = 0;
while (!LL_I2C_IsActiveFlag_STOP(sht4x_context->i2c)) {
if (LL_I2C_IsActiveFlag_RXNE(sht4x_context->i2c)) {
if (i < len) {
buffer[i++] = LL_I2C_ReceiveData8(sht4x_context->i2c);
}
}
}
LL_I2C_ClearFlag_STOP(sht4x_context->i2c);
}
int sht4x_send_cmd(sht4x_cmd_t cmd)
{
}
int sht4x_read_data(uint8_t *buffer, int len)
{
}
int sht4x_measure(int *temperature, int *relative_humidity)
{
uint8_t buffer[32];
// start measurement
buffer[0] = START_MEAS_HIGH_PRECISION;
i2c_transmit(SHT4X_I2C_ADDRESS, buffer, 1);
// delay TODO
volatile int j,k;
for (j = 0; j < 100000; j++);
// read out
i2c_receive(SHT4X_I2C_ADDRESS, buffer, 6);
// TODO
uint32_t t_ticks = (buffer[0] << 8) + buffer[1];
uint32_t rh_ticks = (buffer[3] << 8) + buffer[4];
int t_degC = -45 + 175 * t_ticks / 65535;
int rh_pRH = -6 + 125 * rh_ticks / 65535;
if (rh_pRH > 100) {
rh_pRH = 100;
}
if (rh_pRH < 0) {
rh_pRH = 0;
}
*temperature = t_degC;
*relative_humidity = rh_pRH;
}