Page 1 of 2

SPI version of the ST 7920 GLCD

Posted: Mon Apr 29, 2024 7:46 pm
by estevaon
Hello,

I'm using a ST 7920 GLCD in a project, but it doesn't works in parallel mode ( and use too many pins), I'ts possible to create a SPI version to this component?

Re: SPI version of the ST 7920 GLCD

Posted: Thu May 02, 2024 11:19 am
by BenR
Hello,

Yes looks possible, on your display do you have access to the pin (PSB) that sets if the display has a parallel or serial interface? This is often the limiting factor.

Re: SPI version of the ST 7920 GLCD

Posted: Thu May 02, 2024 11:18 pm
by estevaon
Hello BenR,

Yes, this pin (PSB) exists.

Re: SPI version of the ST 7920 GLCD

Posted: Fri May 03, 2024 10:52 am
by BenR
Great, I've made the change to the component to allow it to be configured as an SPI mode. I've not tested it so let us know how you get on.

The latest version is now available via the Help -> Library updates.

Re: SPI version of the ST 7920 GLCD

Posted: Fri May 03, 2024 9:03 pm
by estevaon
Thank's Ben, it will very useful. I'll test and report the results.

Re: SPI version of the ST 7920 GLCD

Posted: Wed May 08, 2024 11:52 pm
by estevaon
Hi BenR,

Unfortunately, the SPI mode doesn't work, squares appear instead of letters.

Re: SPI version of the ST 7920 GLCD

Posted: Thu May 09, 2024 2:23 pm
by BenR
Ok sounds like the write is maybe working but the read back isn't. I'll have another look at the code.

Re: SPI version of the ST 7920 GLCD

Posted: Thu May 09, 2024 10:08 pm
by estevaon
Thank's BenR

Re: SPI version of the ST 7920 GLCD

Posted: Wed Jun 19, 2024 10:37 pm
by estevaon
Hi BenR, the SPI Version is almost working, I made an example that draws a circle and writes "HELLO", but the cicle and the characters apears with some parts missing. Can you help me?

Re: SPI version of the ST 7920 GLCD

Posted: Thu Jun 20, 2024 4:50 pm
by BenR
Hello,

It looks like the readback function is not quite right. I've had a look at the component code and found a bug so hopefully it's going to work better now. I've pushed the updated component to the library update system so let us know how you get on.