reading that makes me feel you don't understand what I'm speaking about/what you want to do.I meant to say VGA display adapter, instead of one that is HDMI input from the pi zero. I already had a Gert hat on order so will play with that as well. VGA666 hat -> VGA display adapter and force 18 bit depth in config.txt. I will not actually need the pre made hat if I just build onto my pcb.in case you go for custom PCB TFP401 is simple and cheap.
I read the no 18 bit on HDMI in these forums somewhere. I guess I should have dug deeper down that hole, my bad.
Currently I was investigating just incorporating the VGA66 schematic onto my PCB and using a VGA input controller, but your solution seems far more elegant.
Thank you for getting me back on track
What is a VGA666 input controller? You are aware of the function/feature of a VGA666 HAT? You wont be able to connect it to your display without using an AD-Board.
Your method with the TFP401 seems more elegant though, although I do not really want to have to deal with any potential banding due to bit loss, if that is what happens losing RGB0-1. Either way I can do most of it with my pcb, thanks
If your display is 18-bit only it will use 6-bit per color only; nothing gets lots, there is no drawback in performance.
Your display uses an RGB interface which is called DPI as well. In case you don't need the GPIO you can run the display via DPI with (nearly) no interface logic at all. Just wire it up for 18bit - as said that's the color depth - and you can have 4 GPIO left. Using two of them as I2C gives you a lot of flexibility (GPiO extender, LED driver, etc).
TFP401 does not need any GPIO as it is a HDMI to DPI bridge chip.
Below you'll see a 5.7in VGA display ran from a Pi Zero via DPI. All you need is an adapter PCB which is routed for your panels interface and has a 3.3V DC/DC to supply the panels logic supply rail.
Statistics: Posted by aBUGSworstnightmare — Sun Jan 05, 2025 5:32 pm