Clear all

re:GC9A01 Round LCD with ESP32 & Arduino

2 Posts
2 Users
Joined: 1 year ago
Posts: 16
Topic starter  

Hi folks,

In the DBWS video around 29:20 Bill points out an artifact where the inner ring of numbers is erased as the dial moves.

I can duplicate the examples. But for me in the animated dial example when the inner ring is erased I get blocks of white pixels.

When I read from the GC9A01 I get f's. I suspect there is a pull up on my board that is not in the demo version. But it could be other things.

Bodmer (TFT_eSPI, author) mentions that his round display possibly has config pins that do not allow bi-direction data on the SDA pin.

I've duplicated this on my Uno and LOLIN ESP D32-Pro, with the waveshare display and a no-name version from alibaba.

I was wondering if anyone has been able to read from the GC9A01 ? If you've got it to work could you share your hardware?

Joined: 3 years ago
Posts: 5950

I haven't 'played' with this device yet, but did notice when searching for sources that there seemed to be a few possibly different boards out there. Bill points out two of them in the video but I 'think' I saw even more. Or not 😀 

Arduino says and I agree, in general, the const keyword is preferred for defining constants and should be used instead of #define
"Never wrestle with a pig....the pig loves it and you end up covered in mud..." anon
My experience hours are >75,000 and I stopped counting in 2004.
Major Languages - 360 Macro Assembler, Intel Assembler, PLI/1, Pascal, C plus numerous job control and scripting