SPI version of the ST 7920 GLCD

[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?

[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.

[estevaon]

Hello BenR,

Yes, this pin (PSB) exists.

[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.

[estevaon]

Thank's Ben, it will very useful. I'll test and report the results.

[estevaon]

Hi BenR,

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

[BenR]

Ok sounds like the write is maybe working but the read back isn't. I'll have another look at the code.

[estevaon]

Thank's BenR

[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?

[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.