RTL8710读温湿度传感器SHT21

来源：互联网发布：java jdk 64位编辑：程序博客网时间：2024/04/29 11:16
连接RTL8710与SHT21模块

- I2C1 SDA (PC_4) to extended board's SDA
- I2C1 SCL (PC_5) to extended board's SCL
程序

直接复制到SDK里面工程中，替换
#include "device.h"#include "PinNames.h"#include "basic_types.h"#include "diag.h" #include "osdep_api.h"#include "i2c_api.h"#include "pinmap.h"#include "rtl_lib.h"#include <stdbool.h>#define NO_ERROR            0x00#define ACK_ERROR           0x01#define CHECKSUM_ERROR      0x02#define NULL_ERROR          0x03#define MBED_I2C_MTR_SDA    PC_4#define MBED_I2C_MTR_SCL    PC_5#define MBED_I2C_SLAVE_ADDR0    0x40#define POLYNOMIAL 0x131 // P(x) = x^8 + x^5 + x^4 + 1 = 100110001#define MBED_I2C_BUS_CLK        100000  //hz#define I2C_DATA_MAX_LENGTH     16uint8_t i2cdata_write[I2C_DATA_MAX_LENGTH];uint8_t i2cdata_read[I2C_DATA_MAX_LENGTH];int i2cdata_read_pos;volatile i2c_t   i2cmaster;// Sensor Commandstypedef enum{    TRIG_T_MEASUREMENT_HM    = 0xE3, // command trig. temp meas. hold master    TRIG_RH_MEASUREMENT_HM   = 0xE5, // command trig. humidity meas. hold master    TRIG_T_MEASUREMENT_POLL  = 0xF3, // command trig. temp meas. no hold master    TRIG_RH_MEASUREMENT_POLL = 0xF5, // command trig. humidity meas. no hold master    USER_REG_W               = 0xE6, // command writing user register    USER_REG_R               = 0xE7, // command reading user register    SOFT_RESET               = 0xFE, // command soft reset    SerialNumber_location_1  = 0xFA0F,    SerialNumber_location_2  = 0xFCC9}etSHT2xCommand;typedef enum {    SHT2x_RES_12_14BIT       = 0x00, // RH=12bit, T=14bit    SHT2x_RES_8_12BIT        = 0x01, // RH= 8bit, T=12bit    SHT2x_RES_10_13BIT       = 0x80, // RH=10bit, T=13bit    SHT2x_RES_11_11BIT       = 0x81, // RH=11bit, T=11bit    SHT2x_RES_MASK           = 0x81  // Mask for res. bits (7,0) in user reg.} etSHT2xResolution;typedef enum {    SHT2x_EOB_ON             = 0x40, // end of battery    SHT2x_EOB_MASK           = 0x40, // Mask for EOB bit(6) in user reg.} etSHT2xEob;static int SHT2x_GetSerialNumber(uint8_t u8SerialNumber[]);static int SHT2x_WriteCommand8(uint8_t cmd);static int SHT2x_WriteCommand16(uint16_t cmd);static int SHT2x_CheckCrc(uint8_t data[], uint8_t nbrOfBytes, uint8_t checksum);static float SHT2x_CalcTemperature(uint16_t rawValue);static float SHT2x_CalcHumidity(uint16_t rawValue);int SHT2x_ReadUserRegister(uint8_t *pRegisterValue);int SHT2x_WriteUserRegister(uint8_t *pRegisterValue);int SHT2x_Init(uint8_t u8SerialNumber[]){    uint8_t userRegister;           //variable for user register    int error = NO_ERROR;        DiagPrintf("SHT2x_Init \r\n");        i2c_init((i2c_t*)&i2cmaster, MBED_I2C_MTR_SDA ,MBED_I2C_MTR_SCL);    i2c_frequency((i2c_t*)&i2cmaster,MBED_I2C_BUS_CLK);        if (u8SerialNumber == NULL )         return NULL_ERROR;    // --- Reset sensor by command ---    error |= SHT2x_SoftReset();    // --- Read the sensors serial number (64bit) ---    error |= SHT2x_GetSerialNumber(u8SerialNumber);    // --- Set Resolution e.g. RH 10bit, Temp 13bit ---    error |= SHT2x_ReadUserRegister(&userRegister);  //get actual user reg    userRegister = (userRegister & ~SHT2x_RES_MASK) | SHT2x_RES_10_13BIT;    error |= SHT2x_WriteUserRegister(&userRegister); //write changed user reg        return error;}static int SHT2x_GetSerialNumber(uint8_t u8SerialNumber[]){    int error = NO_ERROR;        SHT2x_WriteCommand16(SerialNumber_location_1);      if (i2c_read((i2c_t*)&i2cmaster, MBED_I2C_SLAVE_ADDR0, (char*)&i2cdata_read[0], 8, 1) != 8)        error |= NULL_ERROR;    u8SerialNumber[5] = i2cdata_read[0];//SNB_3    u8SerialNumber[4] = i2cdata_read[2];//SNB_2    u8SerialNumber[3] = i2cdata_read[4];//SNB_1    u8SerialNumber[2] = i2cdata_read[6];//SNB_0        SHT2x_WriteCommand16(SerialNumber_location_2);      if (i2c_read((i2c_t*)&i2cmaster, MBED_I2C_SLAVE_ADDR0, (char*)&i2cdata_read[0], 6, 1) != 6)        error |= NULL_ERROR;    u8SerialNumber[1] = i2cdata_read[0];//SNC_1    u8SerialNumber[0] = i2cdata_read[1];//SNC_0    u8SerialNumber[7] = i2cdata_read[3];//SNA_1    u8SerialNumber[6] = i2cdata_read[4];//SNA_0        return error;}static int SHT2x_CheckCrc(uint8_t data[], uint8_t nbrOfBytes, uint8_t checksum){    uint8_t crc = 0;    uint8_t byteCtr;    int error = NO_ERROR;    //calculates 8-Bit checksum with given polynomial    for (byteCtr = 0; byteCtr < nbrOfBytes; ++byteCtr)    {         crc ^= (data[byteCtr]);        for (uint8_t bit = 8; bit > 0; --bit)        {             if (crc & 0x80)                 crc = (crc << 1) ^ POLYNOMIAL;            else                 crc = (crc << 1);        }        }    if (crc != checksum)         error |= CHECKSUM_ERROR;        return error;}//===========================================================================int SHT2x_SoftReset()//==========================================================================={    int error = NO_ERROR;        SHT2x_WriteCommand8(SOFT_RESET);      Mdelay(15); // wait till sensor has restarted        return error;}//===========================================================================int SHT2x_ReadUserRegister(uint8_t *pRegisterValue)//==========================================================================={    int error = NO_ERROR;        SHT2x_WriteCommand8(USER_REG_R);    if (i2c_read((i2c_t*)&i2cmaster, MBED_I2C_SLAVE_ADDR0, (char*)&i2cdata_read[0], 2, 1) != 2)        error |= NULL_ERROR;    error |= SHT2x_CheckCrc (i2cdata_read,1,i2cdata_read[1]);        return error;}//===========================================================================int SHT2x_WriteUserRegister(uint8_t *pRegisterValue)//==========================================================================={    int error = NO_ERROR;        SHT2x_WriteCommand8(USER_REG_W);    if (i2c_write((i2c_t*)&i2cmaster, MBED_I2C_SLAVE_ADDR0, (char*)pRegisterValue, 1, 1) != 1)        error |= NULL_ERROR;    return error;}static int SHT2x_WriteCommand8(uint8_t cmd){    int error = NO_ERROR;    i2cdata_write[0] = (uint8_t)(cmd&0xFF);  if (i2c_write((i2c_t*)&i2cmaster, MBED_I2C_SLAVE_ADDR0, &i2cdata_write[0], 1, 0) != 1)        error |= NULL_ERROR;    return error;}static int SHT2x_WriteCommand16(uint16_t cmd){    int error = NO_ERROR;    i2cdata_write[0] = (uint8_t)(cmd >>8);i2cdata_write[1] = (uint8_t)(cmd&0xFF);  if (i2c_write((i2c_t*)&i2cmaster, MBED_I2C_SLAVE_ADDR0, &i2cdata_write[0], 2, 0) != 2)        error |= NULL_ERROR;    return error;}static float SHT2x_CalcTemperature(uint16_t rawValue){    rawValue &= ~0x0003;           // clear bits [1..0] (status bits)    return -46.85 + 175.72/65536 *(float)rawValue; //T= -46.85 + 175.72 * ST/2^16}static float SHT2x_CalcHumidity(uint16_t rawValue){    rawValue &= ~0x0003;          // clear bits [1..0] (status bits)    return -6.0 + 125.0/65536 * (float)rawValue; // RH= -6 + 125 * SRH/2^16}int SHT2x_GetTempAndHumi(float *temp, float *humi){    int error = NO_ERROR;    uint16_t rawValueTemp;    uint16_t rawValueHumi;        SHT2x_WriteCommand8(TRIG_T_MEASUREMENT_HM);      //-- read two data bytes and one checksum byte --    if (i2c_read((i2c_t*)&i2cmaster, MBED_I2C_SLAVE_ADDR0, (char*)&i2cdata_read[0], 3, 1) != 3)        error |= NULL_ERROR;    //-- verify checksum --    error |= SHT2x_CheckCrc (i2cdata_read,2,i2cdata_read[2]);    rawValueTemp = i2cdata_read[0] << 8 | i2cdata_read[1];        SHT2x_WriteCommand8(TRIG_RH_MEASUREMENT_HM);      //-- read two data bytes and one checksum byte --    if (i2c_read((i2c_t*)&i2cmaster, MBED_I2C_SLAVE_ADDR0, (char*)&i2cdata_read[0], 3, 1) != 3)        error |= NULL_ERROR;    //-- verify checksum --    error |= SHT2x_CheckCrc (i2cdata_read,2,i2cdata_read[2]);    rawValueHumi = i2cdata_read[0] << 8 | i2cdata_read[1];        //diag_printf("raw temp=0x%x, raw humidity=0x%x, error=%d\n",     //          rawValueTemp, rawValueHumi, error);        //-- calculate humidity and temperature --    if ( error == NO_ERROR ) {        *temp = SHT2x_CalcTemperature(rawValueTemp);        *humi = SHT2x_CalcHumidity(rawValueHumi);    }        return error;}void main(void){    gpio_t gpio_led;int led_status;int i2clocalcnt;int error;    uint8_t userRegister;           //variable for user register    int endOfBattery;           //variable for end of batteryuint8_t sht2x_serialnumber[8];float temperature = 1.123f;float humidity = 2.456f;        DBG_8195A("sleep 10 sec. to wait for UART console\n");Mdelay(10000);        DBG_8195A("start i2c example - SHT2x\n");    error = SHT2x_Init(sht2x_serialnumber);if ( error == NO_ERROR ) {        DiagPrintf("SHT2x init ok, Serial Number = 0x %02x %02x %02x %02x %02x %02x %02x %02x\r\n",                    sht2x_serialnumber[7],sht2x_serialnumber[6],sht2x_serialnumber[5],sht2x_serialnumber[4],                   sht2x_serialnumber[3],sht2x_serialnumber[2],sht2x_serialnumber[1],sht2x_serialnumber[0]);} else {        DiagPrintf("SHT2x init FAILED! \r\n");        for(;;);}while(1){error |= SHT2x_GetTempAndHumi(&temperature, &humidity);                // --- check end of battery status (eob)---        // note: a RH / Temp. measurement must be executed to update the status of eob        error |= SHT2x_ReadUserRegister(&userRegister);  //get actual user reg        if( (userRegister & SHT2x_EOB_MASK) == SHT2x_EOB_ON )             endOfBattery = true;        else             endOfBattery = false;        rtl_printf("temp=%f, humidity=%f, error=%d\n",                    temperature, humidity, error);Mdelay(1000);}}
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