And here we are with the most current iteration of the PCB design. Previously, I had assumed that making all the modules the same was the best solution for this design. In reality, this was only advantageous in terms of manufacturing ease. Separating the phototransistors and LEDs and placing them on different boards allowed a level of miniaturization and integration that I couldn’t achieve before.

In addition, photodiodes were used in place of phototransistors to improve the response of the touch screen and to meet our 100 fps refresh rate target.

Finally here is a picture showing each iteration side-by-side so you can get a feel for how much smaller these boards are.

This entry was posted on Tuesday, September 15th, 2009 at 10:31 pm and is filed under Uncategorized. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.