Display-o-Tron hat - no backlight, only bargraph LEDs


#1

Greetings.

I’ve just attached my DOTHAT for the first time since getting it for Christmas. I’ve followed the lib install guide, and fired up backlight.py.

It runs without complaining, but the backlight doesn’t come on. All I can managed to get working is the bars (these just scan up and down in a loop) and the LCD shows “Such Rainbow!”.

Such irony, more like :P

Can anyone share any things to try and get this working?

TIA.


#2

The output for i2cdetect -l is:

i2c-1 unknown 3f804000.i2c N/A

… and the output of i2cdetect -y 1:

0 1 2 3 4 5 6 7 8 9 a b c d e f 00: -- -- -- -- -- -- -- -- -- -- -- -- -- 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 20: -- -- -- -- -- -- -- -- -- -- -- -- 2c -- -- -- 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 70: -- -- -- -- -- -- -- --

Cheers!


#3

Have same things with mine:
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: – -- – -- – -- – -- – -- – -- –
10: – -- – -- – -- – -- – -- – -- – -- – --
20: – -- – -- – -- – -- – -- – -- 2c – -- –
30: – -- – -- – -- – -- – -- – -- – -- – --
40: – -- – -- – -- – -- – -- – -- – -- – --
50: – -- – -- – -- – -- – -- – -- – -- – --
60: – -- – -- – -- – -- – -- – -- – -- – --
70: – -- – -- – -- – --

No problems.
Have you try the kernel module?
Follow the instruction on my github to add the nospidev at the boot.
Update your kernel with rpi-update.
Load the kernel module (the last 4.1.15-v7+) with insmod and try the precompiled binary client