Bench testing and power-path upgrade for the 1W RAK LoRa repeater.
Today's bench session focused on hardening the primary solar repeater (RAK13302 1W High-Power FEM driven by a Gutol solar power module) against TX brownouts and power instability:
Buffer Bank: Installed a parallel capacitor bank (1000uF Low-ESR electrolytic + 100nF MLCC ceramic) directly at the external 5V input. This eliminates voltage sag during aggressive 1W TX spikes and filters out high-frequency RF line noise.
Rock-solid Link: After 30+ minutes of continuous bench operation, traffic is flowing smoothly with zero frame drops, SNR pegged at +12.5 dB, and zero brownout resets across 10s cumulative TX airtime.
Next step (tomorrow):
Wiring up an INA219 DC current/voltage sensor over I2C. Feeding 5V via the External port causes a ~4.28V leakage onto the RAK's internal VBAT line, blinding standard telemetry to actual battery discharge. Hooking the INA219 shunt directly across the LiPo will give true cell voltage and real-time net current (charge vs. load) in the MeshCore telemetry feed before putting the repeater back out into the field.
Heltec stays in duty as the trusty mobile companion.
#LoRa #MeshCore #RAKwireless #SolarRepeater #Electronics #OffGrid #HardwareHacking #IoT