Hardware-in-the-Loop Evaluation of an ESP32 BLE-to-LoRa Bridge for a Two-Axis Antenna Rotator

Abstract

Extending the control path of a two-axis antenna rotator beyond Bluetooth Low Energy (BLE) range must preserve command integrity and pointing accuracy. This study presents and hardware-in-the-loop evaluates an ESP32 bridge that retains direct BLE and adds point-to-point LoRa through RA-02 modules. The completed campaign covered 43 planned items across direct BLE, BLE-to-LoRa relay, and Internet access. The protocol combined functional acceptance checks with retained serial instrumentation and firmware-path inspection. Authenticated frames returned acknowledgments, encoder angles, link state, and radio-quality telemetry over the same half-duplex channel. Of 37 executed items, 34 fully passed (91.9%), one was partial, and two failed; six items requiring destructive, unavailable-rig, or human-only conditions were reported separately. Signed 5-degree jogs and coordinate pointing executed over both direct and relayed paths. Maximum observed settled two-axis error was approximately 1.3 degrees for direct BLE and 1.0 degree for the bridge, both within the 1.5-degree control tolerance.