I started this project earlier this year and made a basic working prototype. My goal now is to refine it into something that other hobbyists can reproduce easily. The main issues with the current prototype are the following:

1. The cover plate that the camera and the LEDs are attached to is just a badly fitting piece of MDF board with some holes in it. The LEDs are aligned with Blu Tack, and the camera is off-center and incorrectly rotated, which needs to be corrected in the software.

2. The recognition algorithm needs to have some tolerance built into it, since the letter blocks won't always be perfectly aligned with the camera. The current tolerance method is computationally heavy, which leads to a noticeably delay in letter recognition.

3. Ambient light has a significant effect on recognition results, and the prototype only works reliably in low light conditions.

4. There's no proper hardware or software documentation.

I'll try to these problems over the next few weeks, and hopefully create something that others can build for their children.