Several people have asked me in recent weeks if the Amiga RGBtoHDMI boards I designed support the Pi Zero 2. The answer is now “yes”, with some new Pi software, so here is the details.
The Raspberry Pi Zero 2 has recently been released. This is the same form factor as the original Raspberry Pi but the technology on it is closer to the Raspberry Pi 3 series. Close enough that it actually works for PiStorm.
The reason why only the original Pi Zero was supported is because the GPIO access from the CPU is actually a lot slower in all subsequent Pi releases. How much slower? IanSB, the main developer of the RGBtoHDMI software, says it is 36% slower! This is too slow to keep up with the Amiga’s pixel clock.
The solution is one that Claude has been looking into for the PiStorm project, which is using the GPU to access the GPIO which has a much lower latency. IanSB released a new beta version of the software just over a week ago and it works on both the Pi Zero and Pi Zero 2.
You can see it here working perfectly in my Amiga 500 Plus (the blurry disk is due to animation when I took the photo). There are a few unintentional side effects of this new code. First of all it frees up the CPU quite a bit, the original Pi Zero does not need to be overclocked nearly as much as before and there are potential additional image processing that is now possible. Also in-theory the Raspberry Pi 2 and 3 series Pis could now be used with RGBtoHDMI.