Argon won't boot if EN pin connected to 3V3


#1

I added an option to pull the EN pin up to 3V3 on my boards. Although the EN pin is internally pulled-up, I didn’t think it’d hurt. Turns out the Argon won’t boot if it’s directly connected to 3V3.


#2

This doesn’t seem to hold true for me.
My device boots as expected.

Can you post a hi-res pic of your setup?


Update:
I did my test too quickly after having had the device powered, so there must still have been some charge in the caps which allowed the device to actually start up.
More details bellow.


#3

I used test clips to connect 3v3 to EN pin to duplicate.
Running 0.8.0-rc.25, with a loop that just prints “hello world” in SEMI_AUTOMATIC mode.

You need to connect EN to 3V3 before connecting USB power. On the left everything is working fine (LED breathing and hello world streaming). On the Right, the CHG LED will flicker when usb plugged in then nothing happens (No LED or hello world)


#4

Sorry for the late response, but here is the explanation for this behaviour
https://github.com/particle-iot/argon/blob/master/pdfs/argon-v1.00-schematic.pdf

The 3v3 pin is powered by the regulator which is only supplying the 3.3V rail with power when the EN pin is pulled high. But since there are no 3.3V on the 3v3 pin while EN is pulled low this is like plugging an extension lead into itself.