While reading through Hackaday (http://hackaday.com/2016/11/21/diy-optical-sensor-breakout-board-makes-diy-optical-mouse/), I noticed that there is some interest in optical tracking sensors. The most common type are the ones found in optical mice. While those sensors can be useful as optical encoders, there are better options. Pixart, leading manufacturer of mouse sensors, recently added some sensors for optical tracking to their line up. One of these is called PMT9123. It can be used as optical encoder with 2000cpi (0.0127mm resolution) in two axes at speeds up to 25ips (635mm/s) and accelerations of up to 8g. Those values should be sufficient for most 3D printers. Data is output using I2C.

The main issues with this chip are:

1. The chip is most likely not yet in production
2. It is only available to companies that buy enough of these chips
3. The datasheet is not complete
4. There is no breakout board

Since I am currently working with Pixart on a different project, I believe that only the first one is an actual issue. The second one depends on how many of you are interested in this sensor. So let me know here and if there is enough interest, I will get pricing information and start group get.

If you don't have a Hackaday.io account, just leave a comment here: http://hackaday.com/2016/11/21/diy-optical-sensor-breakout-board-makes-diy-optical-mouse/#comment-3282813