Absolute Position Encoder With Single Track Gray Code

I made a rotary encoder. Due to its 60 steps (6 degree) resolution it suits to make clocks.

There is a very good and detailed description of the single track Gray code here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6111776/.

My instructable is only about physical realization now.

Supplies

We need a custom PCB with opto sensors, an Arduino, I used Uno and also need an encoder disc.

Step 1: How Does It Work?

When the disc rotates sensors can detect that dark and light patches change and Arduino can calculate the right position.

Step 2: Schematic Diagram

Arduino connected to the PCB only 4 wires. GND, +5V SDA SCL

Step 3: Yes, This Is the Encoder Disc

Step 4: Hidden Track That Sensors Can Detect

This area that sensors can see.

Step 5: Making an Encoder Disc

You can print out and glue on to the disc surface these pictures, or you can do it manually:

I used 38mm wide insulating tape. Cover the disc like that. Put tape along the disc. Make sure that the tapes meet at the midline of the disc. Scratch with a sharp knife along the 4 red lines. You can remove and swap two pairs of opposite triangles now.

Step 6: Sensors, Dimensions

Step 7:

It shows the disc pattern and reading head distribution of a period-60 code. The generated sequence: [13, 3, 6, 2, 6, 13, 3, 6, 2, 6]. The head interval [5,]. One step will be 360/60= 6°, so step 13 will be 78°. The sensors are 30 degrees apart