Display-o-tron hat backlight is flickering


#1

I haven’t used my display-o-tron hat for awhile, but I wanted to use it with an enviro-phat I just picked up. It displays fine, but when I run the demo program, the backlight constantly flickers, so it’s distracting to use it. It never used to do this.

I’ve got a pi 3 b+, and downloaded the most recent version of the display-o-tron library. Any ideas why it’s flickering so badly? Everything else seems to work fine.

Thanks,
~Collene


#2

Could you have some other code running in the background that’s interfering with it? This is usually the source of weirdness like this.


#3

There’s nothing else running but a terminal with the demo.py program. It’s a new, clean install of the OS, and the only libraries I’ve added are the Pimoroni ones.


#4

did you try running one of the other examples


#5

Yes – the flickering happened while running all the examples that included the backlight.


#6

Is the HAT pushed down firmly, and making good contact with the header?

You mention using it with Enviro-pHAT, how is everything wired up?


#7

Yes, I made sure the connections were good and pushed the hat down firmly on the pins.

I tried connecting it first using a pHAT Stack with the Enviro-pHAT. I then turned off the pi, removed the Enviro-pHAT but still used the pHAT Stack, booted back up, ran the demo, and it was still flickering. So I then just connected the display-o-tron directly on the pi, without the pHAT stack. The flickering happened in all 3 cases.

Thanks,
~Collene