Eric Tsai / Mbed 2 deprecated BLE_Sensor_Temp_Hum_Light

BLE sensor for temperature and humidity using Si7021 and photocell.

Dependencies:   BLE_API mbed nRF51822

Si7021.cpp

Committer:
electronichamsters
Date:
2017-09-24
Revision:
13:64601d952fe4
Parent:
12:45c2bb8231bf

File content as of revision 13:64601d952fe4:

#include "Si7021.h"
 
Si7021::Si7021(PinName sda, PinName scl):i2c(sda, scl)
{
    i2c.frequency(FREQ);
}
 
Si7021::~Si7021()
{
    
}
 
int32_t Si7021::get_temperature()
{
    return tData;
}
 
uint32_t Si7021::get_humidity()
{
    return rhData;
}
 
bool Si7021::measure()
{
    tx_buff[0] = READ_RH;
    if(i2c.write(ADDR, (char*)tx_buff, 1) != 0) return 0;
    if(i2c.read(ADDR, (char*)rx_buff, 2) != 0) return 0;
    
    rhData = ((uint32_t)rx_buff[0] << 8) + (rx_buff[1] & 0xFC);
    rhData = (((rhData) * 15625L) >> 13) - 6000;
    
    tx_buff[0] = READ_TEMP;
    if(i2c.write(ADDR, (char*)tx_buff, 1) != 0) return 0;
    if(i2c.read(ADDR, (char*)rx_buff, 2) != 0) return 0;
    
    tData = ((uint32_t)rx_buff[0] << 8) + (rx_buff[1] & 0xFC);
    tData = (((tData) * 21965L) >> 13) - 46850;
    
    return 1;
}
 
bool Si7021::check()
{
    tx_buff[0] = READ_ID2_1;
    tx_buff[1] = READ_ID2_2;
    if(i2c.write(ADDR, (char*)tx_buff, 2) != 0) return 0;
    if(i2c.read(ADDR, (char*)rx_buff, 8) != 0) return 0;
    
    if(rx_buff[0] == DEVICE_ID)
        return true;
    else return 0;
}