Why is ESP32 restarted when the relay, engine or Wi-Fi is switched on?
Reboot when switching on Wi-Fi or load often indicates a drop in voltage or disturbance. First read the cause reset and check the power supply before changing the software logic.
What to check out
- Test the panel without the relay and engine and with the verified power supply and short cable.
- Observe the tension on the panel during the event. A short drop can be overlooked by the usual multimeter; for such a case is a useful oscilloscope.
- Lead the flow of the engine and relay along the appropriate supply line. Check common signal reference and reverse currents.
- Use the prescribed protection and driver for the inductive load. Select the capacitor and its layout according to the circuit.
A Practical Example
If the ESP32 resets only at engine start, separate the power supply test from the control signal test. Also monitor the heating of the converter and connections.
Common error
Switching off the brownout protection masks the symptom. The rated power of the power supply does not yet prove a good response to current shocks or a small drop on the cable.
For further reading
- Espressif: power and communication diagnostics ESP32 (English). Instructions for finding causes of unstable operation, problems with power supply and connection.
Compatibility check products
Select products according to the above criteria; the list is not a confirmation that they are all interchangeable.
Published:
20.10.2026
