Asked — Edited

Digital Pins Not Working

All the digital pins on one of my 3 EZB V4's stopped working. I rebooted and reset the unit and still can't get the 3 volts at any of the digital pins when I try to turn them on through ARC. I probably burned something up on the EZB but was wondering what type of mishap would cause them all to stop responding? I'm a little leary to just swap out the EZB with a replacement in fear that if I have a bad servo or transistor somewhere in the robot that it would damage the new EZB. Only thing I can remember doing is taking all the servo cables off the unit then reattaching them so I could reroute the wires and I also updated ARC (after a year of not doing any updates). After checking all cables they are plugged in right and I don't recall plugging any in backwards and having to correct it.

I do remember thinking after doing the update after a year of not doing them how much smoother and faster servos were responding now, so I did have digital control for a while after the update. sick


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did you check the fuse


Dave, you might want to try using the web interface to that EZ-B and test the pins from the diagnostics there and with a single servo plugged in to each pin set one at a time. This will eliminate any chance that there is an ARC issue involved.

One of my EZ-B has one bad digital port, and I know it is because I shorted it accidentally.

Does the EZ-B make sound? Can you tell if the analog ports are good? Camera? Wondering if the main cpu is bad (I believe that you can get a wifi connection even without the main board operating).



Thanks for the suggestions. The unit powers up and connects to my network. I can even see it in the Router DCHP list. I can get to it's web interface even. I hadn't thought about trying to check a servo through it. I'll give that a try. All I did was turn random ports on and off through ARC and check them with a multimeter. I've been able to tell if a D port is working like this scene the good old V3 days. lol. Later today I'll remove all the other cables to see if that frees the ports up. I should have tried that first but the whole EZB is full and I need to label the cables before I start pulling them. It wa also getting late, I was getting frustrated my wife was getting a little irritated I had spent the whole evening in the robot lab after working in the yard all day.

This unit is one of the first V4's to roll out of China when they were introduced. It would suck if it's DOA. I'm kinda proud of being one of the ones who waited for so long for it through that Pre-order year. It's also heavily modified with the Sound breakout mod and a power pigtail added. Maybe I caused a problem when soldering on it but it's been running nicely for well over a year. tired


the good news is that microchips don't just "wear out" over time - there are no moving parts, gears, lubrication, etc.. So chips will run for ever, until they are shorted or perhaps peripherals have pulled too much power. The best way to diagnose the ez-b v4 is to run a few tests and narrow down the cause...

  1. does the ez-b v4 make a bootup sound when it turns on?

  2. when ARC "connects" to the ez-b v4, does it do so successfully?

  3. do servos work on the v4?

  4. do analog ports read data on the v4?

If you can perform all of the above, we can start looking into the project code.


OK, I figured this out. There is nothing wrong with the EZB. My power supply voltage was below 7 volts and the EZB automatically shut down the Digital ports (as designed). It's a useful feature for lipo battery users but flustrating for us power supply users that want a supply voltage lower than 7 volts.

I had two options, raise the voltage or enable battery monitoring in the connection control and set the min voltage lower than what I want to supply.