USR button (SW2) causes board to reset in use

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clack
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Joined: Sat May 03, 2014 11:09 am

USR button (SW2) causes board to reset in use

Post by clack » Thu Jan 12, 2017 3:24 pm

Hello,

I have to use X17 as a PWM output but it is also the USR button. The problem is that I have attached a load and a wire to the output which causes the safe mode to activate when the board is turned on. (this mode https://docs.micropython.org/en/latest/ ... reset.html)

I am trying to work my way around it but looking at the schematics there is no way to disable it by removing a resistor or adding anything inbetween (which I have tried with a diode and with a resistor). is my only option to compile the source code with USR switch disabled?

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dhylands
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Re: USR button (SW2) causes board to reset in use

Post by dhylands » Thu Jan 12, 2017 5:33 pm

That sounds about right.

Since you're using it as an output, you could also have that output drive a MOSFET, and have the MOSFET drive your load. If I knew a bit more about your load, I might be able to point you to an appropriate schematic.

clack
Posts: 20
Joined: Sat May 03, 2014 11:09 am

Re: USR button (SW2) causes board to reset in use

Post by clack » Fri Jan 13, 2017 10:17 am

X17 goes into R15 , R3 and U6, I guess its probably the LED U6 that is pulling the pin down! I should have probably used FETs intead of BJTs. Dont worry I guess I was asking if there was somthing else I can do to disable it!
schematic.png
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