What program are you running on the board? Just basic I2C? Which pins are you using?

1. include "mbed.h"

1. define LM75_REG_TEMP (0x00) Temperature Register
2. define LM75_REG_CONF (0x01) Configuration Register
3. define LM75_ADDR (0x28) 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) {

i2c.read(LM75_ADDR, data_read, 4, 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); }

}

The program generate by mbed. And the pin is D14/D15