Library for ADT7410 I2C temperature sensor. Use this instead of TMP102 when you need to measure temperatures lower than -40 degrees C. The device is guaranteed to work at -55 C but will actually read lower temps. See http://mbed.org/users/tkreyche/notebook/adt7140-i2c-temperature-sensor/ for more info.
Dependents: BLE_ADT7410_TMP102_Sample BLE_HTM_HRM1017 BLENano_SimpleTemplate_temp_170802 BLENano_SimpleTemplate_temp_170813 ... more
Diff: ADT7410.cpp
- Revision:
- 0:380ac1ac0101
- Child:
- 8:e1aee50340ec
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/ADT7410.cpp Tue Feb 01 18:57:41 2011 +0000 @@ -0,0 +1,73 @@ +#include "ADT7410.h" + + + // constructor taks paramters and initializes I2C bus +ADT7410::ADT7410(PinName sda, PinName scl, char addr, int hz) + : i2c(sda, scl) + , busAddr(addr) +{ + i2c.frequency(hz); +} + +// destructor +ADT7410::~ADT7410() { +} + +// read 13 bit temperature +float ADT7410::getTemp() { + + char wReg[1] = {TEMP_REG_ADDR}; + char rReg[2] = {0,0}; + float tFin = 0; + int tRaw = 0; + + // set address pointer to temperature register + i2c.write(busAddr, wReg, 1); + + // read temperature register, two bytes + i2c.read(busAddr, rReg, 2); + + // temperature returned is only 13 bits + // discard alarm flags in lower bits + tRaw = (rReg[0] << 8) | (rReg[1]); + tRaw >>= 3; + + // handle positive and negative temperatures + // results in two's complement + if ( tRaw & 0x1000) { + tFin = (float) (tRaw - 8192) / 16; + } else { + tFin = (float) tRaw / 16; + } + + return tFin; +} + +void ADT7410::setConfig(char regVal) { + + char wReg[2] = {CONFIG_REG_ADDR, regVal}; + i2c.write(busAddr, wReg, 2); + return; +} + +char ADT7410::getConfig() { + + char rReg[1] = {0}; + char wReg[1] = {CONFIG_REG_ADDR}; + // need to add repeat to supress stop + i2c.write(busAddr, wReg, 1, 1); + i2c.read(busAddr, rReg, 1); + return rReg[0]; +} + + +// reset the sensor +void ADT7410::reset() { + + char wReg[1] = {RESET}; + i2c.write(busAddr, wReg, 1); + // wait for sensor to reload and convert + wait_ms(250); + return; +} +