DC_BUS_UNDER_VOLTAGE, Power Supply Solid


I thought I had it fixed but I guess not. Should the bus voltage equal the power supply voltage?
I am monitoring the input and it stands at 48.6 volts solid. I ran live plotter and this is what I got.

That looks pretty whack to me.

Yes it should. your image is showing 9V when it should be 48V… not ideal. Unplug everything except the power and see if it’s still borked

Unplugged everything including the brake resistor so only power supply and usb connected.

It must be a hardware problem. I did an erase_configuration. No joy. I am looking for the schematic. Is there one available? I realize this version is not open source but If someone could verify that that circuit is the same I could use an earlier version but I can’t find that either. Could someone maybe tell me where the voltage is monitored because I believe that it must be a sensing problem. I do not see the voltage drop ever I am looking at the power supply input while monitor live plotter [odrv0.vbus_voltage]. Live Plotter is all over the place. I think it should be a nice steady smooth line. Right? Anyway if I can’t figure it out I will have to procure another ODrive.

It should be the same. It’s just a voltage divider directly into the ADC. I assume you’ve used a multimeter and tested the voltage at the input pins and it’s fine?

Also, make sure you’re using the right firmware. The voltage divider value is different between boards so if you’re accidentally using 24V firmware on a 56V board it would be screwed up.

Yeah, That was the first thing I did. I hooked up my scope to monitor it because it is so wacky, I looked at the schematics and figured out the voltage divider thing. I did not think about the firmware angle. I flashed the ODrive with the proper firmware and that did the trick.
Thank you so much. Now I am back to my regular problems.