Display-o-tron not working as expected


Received this morning, and plugged into my PI3, finished the injstallation and it ‘sort’ of works but not as expected. It is acting as if the pins are mis-aligned…

Starting up the backlight only lights the left 3 leds (ass image below). The other backlight leds are only activated as part of the bargraph.py and I can’t display any text.

I have double checked that the Hat is fitted across the pins correctly. Is there anything I can check in software or is it a wiring fault on the Hat?


Which examples are you trying? There are a whole bunch of Display-o-Tron 3000 examples which will not properly work with Display-o-Tron HAT. Judging by your reports, I’d guess you’re running those instead of the HAT ones.

Display-o-tron trouble getting going

In python:

from dot3k import backlight

only lights up the left 3 leds.

from dot3k import lcd
lcd.write(“Hello World”)

does nothing visible.

sudo ./backlight.py in the examples/basic directory works using the left 3 leds only

sudo ./bargraph.py turns on the right 3 backlight leds in turn rather than the side leds.


Ok, hadn’t realised there was a dothat directory as well… must read directory listings better. Using examples from that directory works fine. Thanks.