WitMotion absolute rotary encoder JY-ME01 360° high-precision 18-bit resolution digital rotation angle measurement sensor

I purchased both JY-ME01 and JY-ME02 encoders. They both work. The JY-ME01 is advertised with 18 bit resolution, but the ASCII output appears to be quantized at 15 bits (0.011 degree) even though the degree units output string "Angle:123.456" has 3 decimal digits. When I apply a slowly varying angle, there are clearly steps in the output that are 0.011 degrees apart, even after I average groups of 10 readings together. The JY-ME01 encoder works, but it does not appear to have true 18-bit resolution, at least in this operating mode.

I tested the JY-ME02-485 absolute encoder, which claims 15 bit resolution and also accuracy at that level (0.01 degree). It divides the 360 degree circle into 2^15 = 32768 parts so resolution is about 0.011 degrees, but there is generally 1 count of jitter in any given position; occasionally 2, very rarely 3. So averaging readings is useful. As far as I can determine, the spec is basically correct. I have not yet measured integral non-linearity over large angles, but the device performs as expected for both small angles and long-term drift. Its readings appear correct to +/- 0.01 degrees when reading out at about 10 readings per second and averaging over 10 seconds. I get 94 readings in my Python code in a period of 10 seconds.

Had a couple of set-up issues and the team at WitMotion we're straight on the phone and PC to resolve. Great quality product, great software and most of all, great customer service. Have just ordered one of the Bluetooth units and will defiantly use in the future. Thanks again!