Static Safety and ESD

Electrostatic discharge can silently damage the ESP32 and the radio. The damage is often invisible and appears weeks later as random resets or a dead GPIO.

How bad is it really?

Modern ESP32 chips are reasonably robust, and many builds survive without any ESD precautions. But the radio module and the GPS are more sensitive, and a damaged chip fails at the worst possible moment: in the field.

Practical precautions

• Touch a grounded metal object (a PC case, a radiator pipe) before picking up boards.
• Avoid handling modules on synthetic carpets or in dry winter air.
• Store boards in antistatic bags when not on the bench.
• Handle boards by the edges; do not touch the chip pins.
• If you have a wrist strap and mat, use them. They are cheap insurance.

During soldering

• A mains-grounded soldering iron discharges through the board safely. A cheap ungrounded iron can dump 100+ V of leakage into your circuit; if you get random resets while touching the board, this is the cause.
• Let the board sit for a minute after handling before plugging it into USB if the air is very dry.

Testing for damage

If a board behaves oddly after assembly (random reboots, one GPIO dead, radio fails intermittently), and wiring checks out, suspect ESD damage. The cheap fix is a new $3 ESP32; the cheap prevention is the precautions above.

In the field

The beacon lives in a plastic case with an 18650, so static risk is low. Just do not swap batteries by rubbing the board on a fleece jacket.