One of the regular comments I get on the ESP32 Rainbow is "Really nice, can I plug it into my TV?". It’s always been my plan to add this capability via the "expansion port", so I thought I’d do a quick update on where we are with this.

The new RP2350 ICs really make this nice and simple. You could get DVI output from an RP2040, but that involved overclocking and slightly abusing the hardware. So I’ve been holding off on doing this. But with the RP2350, we now have a built-in peripheral that can generate the required TDMS signals without any overclocking.

So, I’ve run a quick test. I’ve hooked up an RP2350 Pico board to a DVI breakout board.

It’s not pretty, that’s a lot of jumper wires from breadboard to breadboard.

But then, from the expansion port we just need four more wires: a ground and three signal wires for SPI.

I’ve mocked up what the expansion board might actually look like in the future. I’ll be playing with this over the coming months to optimise the layout and make it all fit nicely.

I’m pretty amazed this actually works - on breadboards, with all those crazy jumper wires - but it does.

You can see it in action here:

A few important things to note:

• This does require a board that plugs into the expansion port. Much as I'd love to just incorporate it into the main board, that would really push us off schedule.
• No one really has any idea when the RP2350 chips will be available in any kind of quantity. So production of the expansion board is a little ways off yet. I would really like to include it as a freebie for people who have backed the project. But I can't make any promises around that.
• It may not work on every TV and monitor. We are still pushing the limits of what these tiny MCUs can do and pumping out HDMI signals is a pretty big ask.

Campaign Progress

• The boards are with the CE certification people getting tested. I've started off with basic EMC testing and we'll see how that goes. I'm not too worried if we fail first time, we'll need to do another revision of the boards anyway.
• We're now more than fully funded! Thanks to all the backers. Please keep sharing the project with your friends and on social media. The more backers we get, the more we can do with the project.

Thanks for all your support,
Chris