Temp Library from C.Evans.
TMP102.cpp
- Committer:
- eencae
- Date:
- 2016-02-05
- Revision:
- 0:8818842a3573
- Child:
- 2:1a4fbc01a494
File content as of revision 0:8818842a3573:
// library implemtation file // obviously need to include the header #include "TMP102.h" // we now implement each of the methods listed in the header // note the TMP102:: at the beginning of the method name TMP102::TMP102(PinName sda, PinName scl) { // in the constructor, we create the mbed API objects using 'new' i2c_ = new I2C(sda,scl); led_ = new DigitalOut(LED_RED); } void TMP102::init() { i2c_->frequency(400000); // set bus speed to 400 kHz int ack; // used to store acknowledgement bit char config_data[2]; // array for data char reg = CONFIG_REG; // register address //////// Read current status of configuration register /////// ack = i2c_->write(TMP102_W_ADD,®,1); // send the slave write address and the configuration register address if (ack) error(); // if we don't receive acknowledgement, flash error message ack = i2c_->read(TMP102_R_ADD,config_data,2); // read default 2 bytes from configuration register and store in array if (ack) error(); // if we don't receive acknowledgement, flash error message ///////// Configure the register ////////// // set conversion rate to 1 Hz - CR1 and CR2 are in the second data byte config_data[1] |= (1 << 6); // set bit 6 config_data[1] &= ~(1 << 7); // clear bit 7 //////// Send the configured register value to the slave config register //////////// // create data packet char data_packet[3] = {reg,config_data[0],config_data[1]}; ack = i2c_->write(TMP102_W_ADD,data_packet,3); // send the data packet to the slave write address if (ack) error(); // if we don't receive acknowledgement, flash error message } void TMP102::read_temperature() { int ack; // used to store acknowledgement bit char data[2]; // array for data char reg = TEMP_REG; // temperature register address ack = i2c_->write(TMP102_W_ADD,®,1); // send temperature register address if (ack) error(); // if we don't receive acknowledgement, flash error message ack = i2c_->read(TMP102_R_ADD,data,2); // read 2 bytes from temperature register and store in array if (ack) error(); // if we don't receive acknowledgement, flash error message int temperature = (data[0] << 4) | (data[1] >> 4); temperature_ = temperature*0.0625F; } // temperature accessor method float TMP102::get_temperature() { read_temperature(); return temperature_; } void TMP102::error() { while(1) { // if error, hang while flashing error message led_->write(0); wait(0.2); led_->write(1); wait(0.2); } }