Tom Kreyche
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;
+}
+