SHT3x Library

SHT3x series sensor driver.

• Read Temperature in Raw data, Celsius and Fahrenheit
• Read Humidity in Raw data and percentage
• Control internal heater

Hardware Support

It is easy to port this library to any platform. But now it is ready for use in:

• STM32 (HAL)
• ESP32 (esp-idf)
• AVR (ATmega32)

How To Use

1. Add SHT3x.h and SHT3x.c files to your project. It is optional to use SHT3x_platform.h and SHT3x_platform.c files (open and config SHT3x_platform.h file).
2. Initialize platform-dependent part of handler.
3. Call SHT3x_Init().
4. Call other functions and enjoy.

Example

Using SHT3x_platform files

#include <stdio.h>
#include "SHT3x.h"
#include "SHT3x_platform.h"

int main(void)
{
  SHT3x_Handler_t Handler;
  SHT3x_Sample_t  Sample;

  SHT3x_Platform_Init(&Handler);
  SHT3x_Init(&Handler, 0);
  SHT3x_SetModeSingleShot(&Handler, SHT3x_REPEATABILITY_HIGH);

  while (1)
  {
    SHT3x_ReadSample(&Handler, &Sample);
    printf("Temperature: %f°C\r\n"
           "Humidity: %f%%\r\n\r\n",
           Sample.TempCelsius,
           Sample.HumidityPercent);
  }

  SHT3x_DeInit(&Handler);
  return 0;
}

Without using SHT3x_platform files (esp-idf)

#include <stdio.h>
#include <stdint.h>
#include "sdkconfig.h"
#include "esp_system.h"
#include "esp_err.h"
#include "driver/i2c.h"
#include "driver/gpio.h"
#include "freertos/FreeRTOS.h"
#include "SHT3x.h"

#define SHT3X_I2C_NUM   I2C_NUM_1
#define SHT3X_I2C_RATE  100000
#define SHT3X_SCL_GPIO  GPIO_NUM_13
#define SHT3X_SDA_GPIO  GPIO_NUM_14

int8_t
SHT3x_Platform_Init(void)
{
  i2c_config_t conf = {0};
  conf.mode = I2C_MODE_MASTER;
  conf.sda_io_num = SHT3X_SDA_GPIO;
  conf.sda_pullup_en = GPIO_PULLUP_DISABLE;
  conf.scl_io_num = SHT3X_SCL_GPIO;
  conf.scl_pullup_en = GPIO_PULLUP_DISABLE;
  conf.master.clk_speed = SHT3X_I2C_RATE;
  if (i2c_param_config(SHT3X_I2C_NUM, &conf) != ESP_OK)
    return -1;
  if (i2c_driver_install(SHT3X_I2C_NUM, conf.mode, 0, 0, 0) != ESP_OK)
    return -1;
  return 0;
}

int8_t
SHT3x_Platform_DeInit(void)
{
  i2c_driver_delete(SHT3X_I2C_NUM);
  gpio_reset_pin(SHT3X_SDA_GPIO);
  gpio_reset_pin(SHT3X_SCL_GPIO);
  return 0;
}

int8_t
SHT3x_Platform_Send(uint8_t Address, uint8_t *Data, uint8_t DataLen)
{
  i2c_cmd_handle_t SHT3x_i2c_cmd_handle = 0;
  Address <<= 1;
  Address &= 0xFE;

  SHT3x_i2c_cmd_handle = i2c_cmd_link_create();
  i2c_master_start(SHT3x_i2c_cmd_handle);
  i2c_master_write(SHT3x_i2c_cmd_handle, &Address, 1, 1);
  i2c_master_write(SHT3x_i2c_cmd_handle, Data, DataLen, 1);
  i2c_master_stop(SHT3x_i2c_cmd_handle);
  if (i2c_master_cmd_begin(SHT3X_I2C_NUM, SHT3x_i2c_cmd_handle, 1000 / portTICK_RATE_MS) != ESP_OK)
  {
    i2c_cmd_link_delete(SHT3x_i2c_cmd_handle);
    return -1;
  }
  i2c_cmd_link_delete(SHT3x_i2c_cmd_handle);
  return 0;
}

int8_t
SHT3x_Platform_Receive(uint8_t Address, uint8_t *Data, uint8_t DataLen)
{
  i2c_cmd_handle_t SHT3x_i2c_cmd_handle = 0;
  Address <<= 1;
  Address |= 0x01;

  SHT3x_i2c_cmd_handle = i2c_cmd_link_create();
  i2c_master_start(SHT3x_i2c_cmd_handle);
  i2c_master_write(SHT3x_i2c_cmd_handle, &Address, 1, 1);
  i2c_master_read(SHT3x_i2c_cmd_handle, Data, DataLen, I2C_MASTER_LAST_NACK);
  i2c_master_stop(SHT3x_i2c_cmd_handle);
  if (i2c_master_cmd_begin(SHT3X_I2C_NUM, SHT3x_i2c_cmd_handle, 1000 / portTICK_RATE_MS) != ESP_OK)
  {
    i2c_cmd_link_delete(SHT3x_i2c_cmd_handle);
    return -1;
  }
  i2c_cmd_link_delete(SHT3x_i2c_cmd_handle);
  return 0;
}

int8_t
SHT3x_Platform_CRC(uint16_t Data, uint8_t DataCRC)
{
  return 0;
}

int8_t
SHT3x_Platform_Delay(uint8_t Delay)
{
  vTaskDelay(Delay / portTICK_PERIOD_MS);
  return 0;
}

int main(void)
{
  SHT3x_Handler_t Handler;
  SHT3x_Sample_t  Sample;

  Handler.PlatformInit    = SHT3x_Platform_Init;
  Handler.PlatformDeInit  = SHT3x_Platform_DeInit;
  Handler.PlatformSend    = SHT3x_Platform_Send;
  Handler.PlatformReceive = SHT3x_Platform_Receive;
  Handler.PlatformCRC     = SHT3x_Platform_CRC;
  Handler.PlatformDelay   = SHT3x_Platform_Delay;

  SHT3x_Init(&Handler, 0);
  SHT3x_SetModeSingleShot(&Handler, SHT3x_REPEATABILITY_HIGH);

  while (1)
  {
    SHT3x_ReadSample(&Handler, &Sample);
    printf("Temperature: %f°C\r\n"
           "Humidity: %f%%\r\n\r\n",
           Sample.TempCelsius,
           Sample.HumidityPercent);
  }

  SHT3x_DeInit(&Handler);
  return 0;
}