Setup: regular ESP32 dev board, kabit sa laptop USB. Bare board, walang problema — boots, flashes, lahat OK. Pero ka-wire mo lang ng DHT22 (3.3V, GND, data line with 10k pull-up), boot loop agad. Sa serial monitor: Brownout detector was triggered.
Common reaction: blame the sensor, blame the board. Pero yung brownout detector is doing exactly what it should. The ESP32 wants a steady 3.3V rail, and a laptop USB port plus the onboard regulator can be borderline once may sumasagasa pa ng kuryente. Mas malala if cheap yung cable mo, or kung shared yung port with other USB devices.
Mga nakakatulong na fixes (in order of how often they solve it sa shop):
- Better USB cable. The cheapo "charging only" kind drops half a volt under load. Sayang lang yung debug time.
- Powered USB hub instead of plugging straight into the laptop.
- A 10–100µF electrolytic cap right across the sensor's 3.3V and GND. Smooths out yung dip pag may bigla yung sensor draw.
- External 5V into VIN, skip USB altogether.
Pareho ba sa ESP8266? Iba kasi yung brownout behavior dun (mas marupok actually). Curious if naranasan din ng iba.