Select GPIO from the scheme of your tiles, not just from the number you find in case of code. Some connectors have restrictions or already serve memory, USB-and start-up.

What to check out

• Check the full module and pinout plate label. ESP32, S3 and C5 do not have the same distribution.
• For conventional ESP32 check GPIO34-39 input connections: not suitable for output and do not have pull-up/pull-down internal resistance.
• Exclude connectors that your version uses for flash or PSRAM. Check the starter or strapping pines in particular.
• For relays use the appropriate module or driver. GPIO must not directly supply the coil; also check the output status during the reset.

A Practical Example

A key that holds the start-up connection in the wrong state when switched on can prevent the running of an otherwise correct program. Try starting with the unplugged key and then select a more suitable GPIO.

Common error

To ESP32 do not connect 5-V either 24-V signals directly. Connection designation on connector and GPIO number in code are not always the same thing.

For further reading

• Espressif: starting connections and start-up mode ESP32 (English). Interpretation of strapping pines and signals that influence the launch of the classical ESP32.

Compatibility check products

Select products according to the above criteria; the list is not a confirmation that they are all interchangeable.

• ESP32 38 pin WIFI IoT Bluetooth
• ESP32-S3 N16R8 WiFi development panel BT 8MB PSRAM
• Double 5V DC automatic relay with diode and optocopler