ESP32 WiFi Dropout Fix

Spent three evenings tracking down random WiFi disconnects on an ESP32 DevKit. The symptom was a reconnect every 15-30 minutes with no obvious pattern in the logs.

Eventually I noticed the dropout correlated with the onboard voltage regulator getting warm. The ESP32 WiFi radio pulls a burst current that the AMS1117 3.3V regulator on my dev board couldn't cleanly supply. Adding a 100uF electrolytic cap directly on the 3.3V pin (with a 100nF ceramic in parallel for high-frequency decoupling) solved it completely.

Lesson learned: always check your power supply under RF load. A good bench supply with a current display is invaluable here — I saw spikes up to 350mA during WiFi association that were causing the rail to droop about 200mV.