picodvi VS showmewebcam

The RP2040 is a great MCU for playing with graphics as it can bit bang VGA and DVI/HDMI. There's some info on the DVI here: https://github.com/Wren6991/PicoDVI

I wrote a couple of articles on how to do bit banged VGA on the RP2040 from scratch: https://gregchadwick.co.uk/blog/playing-with-the-pico-pt5/ and https://gregchadwick.co.uk/blog/playing-with-the-pico-pt6/ plus an intro to PIO https://gregchadwick.co.uk/blog/playing-with-the-pico-pt4/

A few years back someone was bit banging DVI and 720p 30fps video straight off the RP2040 GPIO pins with just inline resistors between not and the HDMI cable.

https://github.com/Wren6991/PicoDVI

I have the Adafruit DVI board and have been hacking on it some. It's more fun than should be allowed.

There's a project to get this running using Rust[1]. Currently it outputs the blue channel with sync, but has trouble with the other two channels. I don't have a hardware lab with scope, logic analyzer, etc., so it's not easy for me to debug.

In the meantime, I've been doing some experiments in the C codebase as well[2], mostly in the direction of proportionally spaced bitmap text, using the fonts in the X11 distribution.

[1]: https://github.com/DusterTheFirst/pico-dvi-rs

[2]: https://github.com/Wren6991/PicoDVI/pull/48

There is even bit-banged DVI library for pico.

Apparently, there is a digital video output project for the RP2040 already out there [0]! As for why digital video is more rare, it is because the common digital video formats are higher bandwidth and require higher signal integrity.

[0] https://github.com/Wren6991/PicoDVI

I've seen people implement DVI with PIO, and I'm sure basic missile commands wouldn't be as bandwidth-intensive as that.

For example this guy (https://github.com/Wren6991/PicoDVI) essentially 'bit bangs' CML. Sure its not a completely compliant implementation, but it's pretty close... In his case using a push pull with 3.3V/0V. I don't know how he's getting a 0.8V swing.

Yes! I use pi zero and a 3D printed case with the HQ camera and a decent lens. The field of view is exactly right for video calls.

https://github.com/showmewebcam/showmewebcam/releases

Also related: Take a Raspberry Pi Mini, a Raspberry Pi HQ camera, and install this firmware

https://github.com/showmewebcam/showmewebcam

and it turns your Pi into a USB webcam with a C mount lens.

The Pi Zero runs https://github.com/showmewebcam/showmewebcam and presents itself as a generic USB webcam to operating systems.

I use showmewebcam for the usb-capability, but I think it's possible to have it wireless.

Very nice! I'm also planning on testing it out with the showmewebcam software, which might make it even more customizable! https://github.com/showmewebcam/showmewebcam

You want to take a look at buildroot-based approaches. They're not quite instant-on, but they're tolerable. https://github.com/showmewebcam/showmewebcam is a good example.

With the composite kernel driver you can create as many virtual gadgets as you want from a single usb otg port. Lots of people have done it and documented extensively for the pi0. Here is my list (look at the composite gadget section): https://github.com/showmewebcam/showmewebcam/wiki/Further-Documentation

> So there is a market gap between so-so webcams for $100-200 and a full-blown setup with a mirrorless camera, an external mic and lighting panels that will cost almost a grand or two, if you're so inclined.

Try our free software project that uses a Pi and its HQ sensor to make a USB webcam [1]. You'll have a wide range of lenses [2] and cases [3] that people cook up for their personal use.

Last time I commented here, there have been criticisms about the quality of the lens that the Pi foindation sell. We have discovered many other decent alternative lenses that help remedy the quality and distortion issue of the stock lenses. An example of a good guide is the commonlands lens guide [4].

The software is very actively developed and we have a pretty supportive community with good software engineering practices. Check it out, you might even like it!

1. https://github.com/showmewebcam/showmewebcam

2. https://github.com/showmewebcam/showmewebcam/wiki/Lenses

3. https://github.com/showmewebcam/showmewebcam/wiki/Cases

4. https://commonlands.com/blogs/camera-engineering/raspi-video...