Byoungsul Lee
/
Temperature_I2C
i2c temp sensor
Fork of Nucleo_i2c_mcp9808 by
main.cpp
- Committer:
- bcostm
- Date:
- 2014-02-21
- Revision:
- 0:41f53df528da
- Child:
- 1:404c34e19f93
File content as of revision 0:41f53df528da:
#include "mbed.h" #define LM75_REG_TEMP (0x00) // Temperature Register #define LM75_REG_CONF (0x01) // Configuration Register #define LM75_ADDR (0x90) // LM75 address I2C i2c(I2C_SDA, I2C_SCL); DigitalOut myled(LED1); Serial pc(SERIAL_TX, SERIAL_RX); volatile char TempCelsiusDisplay[] = "+abc.d C"; int main() { char data_write[2]; char data_read[2]; /* Configure the Temperature sensor device STLM75: - Thermostat mode Interrupt - Fault tolerance: 0 */ data_write[0] = LM75_REG_CONF; data_write[1] = 0x02; int status = i2c.write(LM75_ADDR, data_write, 2, 0); if (status != 0) { // Error while (1) { myled = !myled; wait(0.2); } } while (1) { // Read temperature register data_write[0] = LM75_REG_TEMP; i2c.write(LM75_ADDR, data_write, 1, 1); // no stop i2c.read(LM75_ADDR, data_read, 2, 0); // Calculate temperature value in Celcius int tempval = (int)((int)data_read[0] << 8) | data_read[1]; tempval >>= 7; if (tempval <= 256) { TempCelsiusDisplay[0] = '+'; } else { TempCelsiusDisplay[0] = '-'; tempval = 512 - tempval; } // Decimal part (0.5°C precision) if (tempval & 0x01) { TempCelsiusDisplay[5] = 0x05 + 0x30; } else { TempCelsiusDisplay[5] = 0x00 + 0x30; } // Integer part tempval >>= 1; TempCelsiusDisplay[1] = (tempval / 100) + 0x30; TempCelsiusDisplay[2] = ((tempval % 100) / 10) + 0x30; TempCelsiusDisplay[3] = ((tempval % 100) % 10) + 0x30; // Display result pc.printf("temp = %s\n", TempCelsiusDisplay); myled = !myled; wait(1.0); } }