DIY hand-held games console: Faster GUI
Last updated: 19 Apr 2023 - 22:19
It's been a while since I got anything done on the Noodle Game console, but I found it on my desk and had a few minutes to spare so thought I'd have a crack at upgrading the screen driver code. It was a little bit of a disappointing exercise but at least I've learned some things.
Stuck in 24 bit
The screen supposedly supports a bunch of different colour depths including 18 bit (6 bits of each colour) note that this isn't a nice multiple of 8, a 16 bit mode where green has 6 bits but red and blue only 5 and apparently even a 3 bit mode where it has just one bit per colour like a Sinclair Spectrum. Unfortunately in SPI mode it only supports either the 8 bit or the full 18 bit modes. In 18 bit mode the colours are padded to a full byte each and so need three bytes per pixel.
Slow clock
The screen module I've got is hard-wired to SPI mode. The module can do parallel RGB, host bus or even MIPI-DSI apparently all of which offer faster data transfers and a choice of colo
DIY hand-held games console: Screen Driver
Last updated: 13 Jul 2022 - 22:40
Now that the toolchain and the basics are working, the next thing to do is to start getting some of the peripherals working. I like to do this one at a time and it's usually best to start with the outputs first, that way you can use the outputs to test whether the inputs are working. We've proven the basic UART comms already, so the next big output device is the screen. The screen I've got came from eBay but appears to match up with this entry on LCD Wiki.