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Grand Central USB stopped working
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

Re: Grand Central USB stopped working

by evgbrowns on Mon Apr 06, 2020 1:19 pm

So I think we've reached the conclusion I feared, that my GCM4's USB port is broken and not something I can recover. The guide says there's a fuse that will shut off temporarily when more than 1A is drawn, to protect the computer's USB port. I guess whatever happened it didn't protect the GCM4's port.

Going forward, my main concern is not repeating this. I presume my best approach is to ensure I've got a solid common ground with a new GCM4, RPi and my external power supplies, does that make sense? This GCM4 will connect to the RPi UART, 25 solenoid driver MOSFETs, and one Neopixel LED strip - the latter two having external power for their devices. Would you recommend I just power the GCM4 from the powered USB hub, or should I continue with the external power supply? My second GCM4 will have a UART connection, about a dozen servos, a dozen proximity switches, and another Neopixel strip, I would prefer to use the same power approach with both unless there's a reason not to.

I understand your manufacturing and shipping people are all totally consumed doing amazing work at this time. Everyone in your company should be proud of the contributions you are making. I know I can't buy another GCM4 from you directly from some time, but DigiKey has some, so I ordered one from them to continue my development. When things return to some semblance of normal, is my current board something that can be returned for repair, or just the next occupant of my electronics to be recycled pile?

Thanks for all your help.

evgbrowns
 
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Re: Grand Central USB stopped working

by adafruit_support_bill on Mon Apr 06, 2020 2:39 pm

The guide says there's a fuse that will shut off temporarily when more than 1A is drawn

Depending on the specifics of the grounding issue, you can end up with current flowing in unintended directions. That can cause plenty of damage without rising to the level that would trip a fuse.

When working with multiple supplies, it is important to make sure you have a good common ground before you start making connections between components.

Would you recommend I just power the GCM4 from the powered USB hub, or should I continue with the external power supply? My second GCM4 will have a UART connection, about a dozen servos, a dozen proximity switches, and another Neopixel strip, I would prefer to use the same power approach with both unless there's a reason not to.

I would power the GCM4s via the USB hub and use an external supply for your noisy high current loads like servos and neopixels.

When things return to some semblance of normal, is my current board something that can be returned for repair

The Grand Central uses the native USB capability of the M4 processor chip. So any repair of the USB would involve replacing the whole chip.

adafruit_support_bill
 
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Please be positive and constructive with your questions and comments.