Voltage not displaying on Classmate

Hey everyone,

Last time we tested out robot before ship date, the voltage was not outputting on the classmate screen.

The voltage on classmate displayed “0.00” the entire time.

The robot communicated with the classmate; the classmate recognized the joysticks. We ran code and everything worked correctly. I had the latest driver station update and the latest Crio image, I double-checked.

I was also running the radio in access point mode and communicated wirelessly with the classmate, without using an extra router.

Any ideas?


make sure you have a jumper on the analog breakout board, on the two pins at the very very end (away from the power, don’t remember what they say off the top of my head)

The most common cause of this problem is a lack of power to the analog breakout card. Check to confirm that the LED on the analog breakout is lit. If the LED is not lit, check the power wire to the PDB and the circuit breaker in the PDB.

The second most common cause (as mentioned by byteit101) is to ensure that the jumper on the analog breakout card is correctly positioned.

I would note that having voltage correctly displayed on the classmate is a requirement to participate in practice matches at regional events, so you’ll want to fix this ASAP when you get to your first event.

Are you using any analog inputs on the analog breakout?

Make sure you have power connected to the analog breakout board and the green power LED on the board is on. Also, check that you have a breaker in the right spot on the power distribution board. Don’t ask me how I know this :slight_smile:


This is the voice of experience. Once you have verified that the jumper is in place and have verified the Analog breakout is powered, verify that Analog input #8 is not called or used anywhere in your code.

Check for loose wires from the PD to the analog breakout – use a multimeter to check the voltate at the module. Also, verify that the analog module is in slot 1.

Greg McKaskle