Detailed Description

Driver for the Si7021 I2C Humidity and Temperature Sensor.

Version: 5.1.1

License

This file is licensed under the Silicon Labs License Agreement. See the file "Silabs_License_Agreement.txt" for details. Before using this software for any purpose, you must agree to the terms of that agreement.

Definition in file si7021.h.

#include <stdlib.h>
#include <stdint.h>
#include "si7021_config.h"

Go to the source code of this file.

Macros
#define	SI7021_CMD_MEASURE_RH 0xE5

#define	SI7021_CMD_MEASURE_RH_NO_HOLD 0xF5

#define	SI7021_CMD_MEASURE_TEMP 0xE3

#define	SI7021_CMD_MEASURE_TEMP_NO_HOLD 0xF3

#define	SI7021_CMD_READ_FW_REV {0x84, 0xB8}

#define	SI7021_CMD_READ_HEATER_CTRL 0x11

#define	SI7021_CMD_READ_ID_BYTE1 {0xFA, 0x0F}

#define	SI7021_CMD_READ_ID_BYTE2 {0xFC, 0xC9}

#define	SI7021_CMD_READ_TEMP 0xE0

#define	SI7021_CMD_READ_USER_REG1 0xE7

#define	SI7021_CMD_RESET 0xFE

#define	SI7021_CMD_WRITE_HEATER_CTRL 0x51

#define	SI7021_CMD_WRITE_USER_REG1 0xE6

#define	SI7021_CONFIG_DEVICE_ID 0x21

#define	SI7021_CONFIG_I2C_BUS_ADDRESS 0x40

#define	SI7021_CONFIG_I2C_DEVICE (I2C0)

#define	SI7021_DEVICE_ID SI7021_CONFIG_DEVICE_ID

#define	SI7021_ERROR_I2C_TRANSFER_FAILED 0x0002

#define	SI7021_ERROR_I2C_TRANSFER_NACK 0x0001

#define	SI7021_ERROR_INVALID_DEVICE_ID 0x0003

#define	SI7021_ERROR_TIMEOUT 0x0004

#define	SI7021_I2C_BUS_ADDRESS SI7021_CONFIG_I2C_BUS_ADDRESS

#define	SI7021_I2C_DEVICE SI7021_CONFIG_I2C_DEVICE

#define	SI7021_OK 0

Functions
uint32_t	SI7021_cmdRead (uint8_t cmd, size_t cmdLen, uint8_t result, size_t resultLen)
	Sends a command and reads the result byte(s) over the I2C bus. More...

uint32_t	SI7021_cmdWrite (uint8_t cmd, size_t cmdLen, uint8_t data, size_t dataLen)
	Sends a command and data to the chip over the I2C bus. More...

void	SI7021_deInit (void)
	De-initializes the Si7021 chip. Disables the sensor power domain, this also disables other sensors. More...

uint32_t	SI7021_getFwRev (uint8_t *fwRev)
	Reads the firmware revision of the Si7021 chip. More...

uint32_t	SI7021_init (void)
	Initializes the Si7021 chip. More...

uint32_t	SI7021_measure (uint32_t rhData, int32_t tData)
	Performs relative humidity and temperature measurements. More...

Detailed Description

License

Macros

Functions