I have been using a Raspberry Pi Zero W for the last few weeks, and have it set up to connect to a hotspot automatically. Yesterday, I was using the GPIO pins to drive an L293D motor controller -- during this time some of the standard breadboard cables that I was using seemed to burn out, but most were fine. I didn't think much of it, but when I started my hotspot and went to ssh into my pi, I found that it would not connect. I had another zero that was configured similarly; it connects to my hotspot, and swapping the SD cards between the two pi's doesn't change either's ability to connect.

I followed several wifi troubleshooting guides, but most just said to make sure the wlan0 interface was up. I'm not sure if mine is -- whenever I run sudo iw wlan0 scan (that command may not be exactly right, I couldn't remember it just off the top of my head) I get wlan0: ERROR while getting interface flags: No such device. Checking ifconfig shows only lo and usb0 (the latter is for Ethernet Over USB). I also made some minor edits to some interface config files while following other guides, but those made no difference either.

I'm thinking my built in wifi is just gone, but everything else on the board is totally fine (at least it seems to be), so I was just wondering if there was a tool I could use to verify that the wifi chip is dead before I spent much more time trying to fix it. Alternatively, if anyone knows how to fix my issue, that would be greatly appreciated as well. ;)


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    Try building a fresh new SDCard with plain Raspbian. If that doesn't work then you can assume you've fried it by motor controller abuse (which is a common ailments). When you get your next RPi be more careful. Check all wiring twice before you shoot another RPi dead. – Dougie Jan 8 '19 at 7:59
  • @Dougie is it bad to tie the ground of my motor power source to a ground pin of my RPi? That’s the only somewhat sketchy thing I can think of that I did. – Arik Rundquist Jan 8 '19 at 19:47
  • You need to isolate your RPi so that it only has V+ (pin #16) GPIO to EN1 (pin #2 or pin#15) and GND (most things I can find use pin#13 for GND) connections to the control pins on your motor controller. The motor side of the controller should be on a separate power supply and as isolated as possible from the RPi. rs-online.com/designspark/… appears to be a good article on doing this stuff. You can't avoid connecting RPi GND to L239D GND. – Dougie Jan 8 '19 at 20:18

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