Overview
The first rung on the RF ladder: before designing antennas that steer electronically, build one that steers mechanically. An ESP32 drives two NEMA17 steppers through DM542T drivers, pulls live satellite positions from the N2YO API every 10 seconds, converts them to azimuth/elevation solutions, and tracks.
Details that mattered
- Resolution: 8:1 azimuth and 10:1 elevation gear reductions — 3D-printed gear trains — give ~0.028°/step effective resolution.
- Homing: Hall-effect sensors for repeatable startup positioning.
- Safety: software travel limits and an e-stop, because steppers with gear reduction will happily eat their own wiring loom.
- Control: a self-hosted responsive web panel with a satellite picker, tracking and manual modes, sensor tests, and live status.
Pre-configured targets: Inmarsat, GOES, and NOAA birds.
Status
The build is complete — firmware, UI, gearing, homing all done as of late 2025. What it’s waiting on is the other half of the project: fabricating the L-band antenna it’s supposed to point, then the first sky test and SDR I/Q capture (RTL-SDR/HackRF One). It’ll come off the shelf when the RF program cycles back around.