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OLED Goes blank after PTT.

Posted: Wed Jun 05, 2019 11:00 pm
by K8GLX
https://www.youtube.com/watch?v=ChObvCqRcHg

Specs:

Pi-Star:4.0.0-RC4
Raspberry Pi 3b+
eBay clone MMDVM Pi Hat (Duplex) (STM-32)
.96 DIYMALL OLED -- I have replaced them twice, and the original one worked just fine on my DVMEGA for 2 years.

I can recover the screen by resetting the OLED in pi-star, it will say "IDLE" "CW TX" or display the screensaver, but the second I PTT it will go blank and stay blank until it's reset. It has worked occasionally, but very rarely.

Any suggestions?

Re: OLED Goes blank after PTT.

Posted: Thu Jun 06, 2019 9:00 am
by KE7FNS
key up your radio and get the screen to go blank.

This assumes a newer pi, so if that is the case continue, if it reports an error cause you are on an old pi, use a 0 instead of a 1

Open up SSH, type "i2cdetect -y 1"

Do you see a grid with --'s displayed everywhere except one that says something like 3c??

If you do, then thats good, that means the OLED is responding to a query of its address, which means it isn't locked up, so could be a pixel dimming issue or something.

If you get an address of the board (normally 3c, but could be something else), then post the [OLED] section of the config, maybe you have some brightness setting turned too low or inverted or something.

Then again, it could be something like RF getting in a messing around with things. I guess what I'd try at that point is to find some demo scripts that draw images on the screen using python and i2c or something simple. Then disable the screen in the Pi-star configuration, run the scripts to draw images on the screen, and key up and see if it blanks out. If it blanks out, then that pretty much confirms some sort of power draw or RF issue, if it works fine, then that kinda would point to a configuration issue in pi-star. Hope that helps, let me know if you need help finding some i2c demo scripts. Shouldn't be hard to find.