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; }