pic: On board voltmeter



Is your robot behaving erratically due to low voltage? 8 buck from adafruit and it is easy to check at a glance

Cool! Is it legal?

Not in that configuration. An inspector is never going to pass that 24 gauge wire being protected by a 40A breaker. Switch it over to on of the smaller terminals and plug in a 20A (but preferably 5A) circuit breaker, and THEN it will be legal. It’s just a custom circuit, after all.

It’s purpose though is mainly debugging before you get to the field. When the robot doesn’t work there is a tendency to stare at it while the kids wiggle the controls. Now a little bit of insight might be gain, while scratching at the beard.

I had a similar idea this summer.

I was planning to put one of these on our robot but I couldn’t find a purple 7 segment LED to replace the green ones with. I might get one any way.

I’ll just leave this here…
Three Digit Purple 0.56 Inch (14.20mm) LED Display Anode
0.56 Inch (14.20mm) Three Digit LED Display - Purple (Cathode)

You get to figure out if it’s worth having 9 extra displays. And whether you need common cathode or common anode.

9 extra? Those are just the ones for our next 9 robots. Thanks Kevin.

I’m guessing you just looked on Mouser and Digikey and such, because I just Googled “purple seven segment”.

For anyone else interested in customizing their voltmeter, LC LED offers the 3 digit display red, green, orange, blue, yellow, purple, and white. Only trick is that you have to order a “sample” of 10 displays for $29.80. So if you’re looking for a more common color, Mouser or Digikey is probably an easier solution.