Stock Yaesu rotor computer interface runs about $600 without cables, and Green Herron is similar price. Decided to try the K3NG Arduino solution instead. Using Arduino UNO R3 ($30) with Seeed Relay Shield ($20), plus proto board and MOSFET - total cost around $68. With Ham Radio Deluxe 5.0, the rotor turns smoothly and stops within +/- 1.0 degrees of target - exactly what I wanted for my setup. Had to adjust data rate to 9600bps for HRD compatibility since it doesn't support the default 115200bps, but now I can double-click anywhere on the planet and have automatic rotor pointing. Anyone else made the switch from commercial controllers? The K3NG firmware emulates Yaesu GS-232A/B and Easycom protocols and can easily interface with commercial rotator control units or serve as complete replacement.

Been running K3NG controller for 3 years on my G-5500. The updated code with slow startup and brake operation works perfectly, configured for 450-degree rotation capability. Saved $500+ over commercial solutions.

John W3SA tested on Yaesu Az/El unit and contributed elevation code updates. Anthony M0UPU offers PC boards, and G4HSK documented his G-5500 project using this code. Lots of community support available.

What's your experience with the PWM motor control? The motor board operates silently and isn't subject to mechanical wear like relays. Thinking of upgrading from my relay-based setup for smoother operation.