It took me a few years of fits and starts but I've finally got my DIY persistence of vision bike light to display video!<p>I designed and built the PCB for it and wrote the code for the wifi streaming of video frames with a bit of help from Claude. This was actually one thing I was dreading as I was hitting a wall being burned out on this project. With a little bit of Claude's help in getting the ESP32 wifi stack working It's finally finished!<p>Some tech specs:
Using an ESP32
42 LED's per strip, 4 strips total spaced 90 deg apart.
Angular resolution of the image is 1 deg so it updates all 168 LED's , 360 times per rotation.<p>The LED's are SK9822 individually addressable LED's (also known as DotStar from Adafruit).<p>Uses a magnet and hall effect sensor to keep track of rotation speed.<p>The server can be run from a phone and using termux with a python server to serve locally to the esp.<p>I need to periodically spin it up every time it slows down.<p>My video camera shutter speed needs to be slow to show the correct effect otherwise it is either incomplete or it shows too many "frames" in a video frame.<p>Gonna get around to making a blog post at some point to talk more about it in detail!
Amazing! Maybe Divvy should fit it in their bikes. Parallel going traffic will not see it; only the pedestrians. So< i guess it's not a traffic risk. Another revenue for them?
Wow, thank you for sharing this. What happens - just out of curiosity - when the wheel slows down or stops moving altogether? That is, what is the effect like then?