In March of 2003 Circuit Cellar published a feature article on using position sensing detectors (PSD). The project builds a 2D position sensor using a PIC16F873 as the microcontroller, an Aculux PCB set and a Hamamatsu PSD. Since that project is now over 10 years old, what modern project or device configuration can I use to get the same or better functionality?

  • \$\begingroup\$ What are your criteria for "better functionality"? Response time, accuracy, resolution, distance, light-level, ...? \$\endgroup\$
    – gbulmer
    Dec 23, 2015 at 17:40
  • \$\begingroup\$ @gbulmer I am mostly interested in a slightly better resolution. The Circuit Cellar project has a 0.001" resolution and ideally I would like an instrument which would clearly resolve deviations of 0.0001" (10x better resolution) \$\endgroup\$ Dec 23, 2015 at 17:43
  • \$\begingroup\$ 10x is quite a lot better. Would your application use a laser like the original Circuit Cellar article (I assume it is "2-D Optical Position Sensor" by Roger Johnson & Chris Lentz) \$\endgroup\$
    – gbulmer
    Dec 23, 2015 at 18:18
  • \$\begingroup\$ @gbulmer I guess I would be willing to use whatever kind of laser is required. I have a Bosch laser level which is similar to the one in the project, but higher quality. Its stated accuracy is 1/4" in 75 feet or 0.0025" in 9 inches. \$\endgroup\$ Dec 23, 2015 at 18:34

1 Answer 1


That is still a good approach. If the terrain is even, like a hard floor, a laser mouse sensor is a good option.

On the extremely complicated end, computation and algorithms have come a long way, so things like LIDAR or Microsoft Kinect for room navigation is much more feasible. But for low-end sensing, I don't think there is much difference now.


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