Getting negative value for temperature

Reply to Getting negative value for temperature on Sun, 05 Nov 2017 17:33:15 GMT

deep00 — Sun, 05 Nov 2017 17:33:15 GMT

Hi,
I'm following the tutorial : https://docs.onion.io/omega2-arduino-dock-starter-kit/arduino-kit-reading-a-temp-sensor.html to get the temperature with the omega arduino dock and the TMP GZ 36 sensor.
The problem is that i'm getting negative values.

0.09 volts

-40.72 degrees C

-41.30 degrees F

0.00 volts

-50.00 degrees C

-58.00 degrees F

0.00 volts

-50.00 degrees C

-58.00 degrees F

Can some one help me to solve the problem or point me where i can search.

Thank you

Reply to Getting negative value for temperature on Sun, 05 Nov 2017 18:16:45 GMT

Maximilian Gerhardt — Sun, 05 Nov 2017 18:16:45 GMT

@deep00 Have you verified the sensor to be working on a stand-alone Arduino? Are you sure the wireup is correct? It's easy on this sensor to confuse the orientation and switch VCC and GND.

You should try to power it up from just 5V and GND and measure the voltage on the V_OUT pin yourself with a multimeter. If you wiring is correct but you still get a reading of 0 volts, your sensor is dead.

(From http://www.analog.com/media/en/technical-documentation/data-sheets/TMP35_36_37.pdf)

Reply to Getting negative value for temperature on Mon, 06 Nov 2017 11:16:56 GMT

deep00 — Mon, 06 Nov 2017 11:16:56 GMT

You have right.
The sensor is dead, i replace it and it works fine.