Safe mode without reset button?

I have a custom PCB that only has the setup button (next revision of the board will definitely have both).

I was attempting to see if I could send bad firmware, put the device in an error mode, and then update the firmware over wifi. I should have been using my prototype to test this out instead of my PCB but hindsight…

Is there any way I can force it to safe mode via USB?
I did have a 10 pin JTAG portion added to the board but I’ve never worked with that before… Anyone know what hardware I need to buy in order to use that?


you can hold the setup button as you apply power, does the same thing as the reset button.

also the jtag has the rst pin, so you could just gnd that to “press” the reset button. its pin 15 on the 20pin connector of the standard jtag, not sure about the 10 pin one

1 Like

Yeah, I smashed the setup button a few times and got it to work. Thanks, I’ll try messing around with the JTAG as well.

I want to see if I can repeat it but I’ll use my P1 red board I got from spark fun this time instead :smile: