ESP32 Boards

ESP32 boards put Wi-Fi and Bluetooth on a fast dual-core chip, so a project can talk to your phone, a dashboard or the cloud without an extra module. You program them in the Arduino IDE once the ESP32 board package is added.

The classic ESP32 (30-pin DevKit) has Wi-Fi, Bluetooth Classic and BLE. The ESP32-C3 and ESP32-S3 are newer, BLE-only chips with native USB; the S3 adds more memory for camera and AI work.

How to choose:

  • Pick the classic ESP32 for Bluetooth audio or serial.
  • Pick the C3 for small, low-cost Wi-Fi builds.
  • Pick the S3 for heavier tasks.

Two rules matter on every ESP32:

  • The GPIOs are 3.3V only and not 5V tolerant, so 5V sensor outputs need a divider or level shifter.
  • Use ADC1 pins (GPIO32-39) for analog readings. ADC2 pins cannot be read while Wi-Fi is on.

Avoid GPIO6-11, which connect to the flash chip. Be careful with the strapping pins (GPIO0, 2, 5, 12 and 15), because a sensor holding one at reset can stop the board booting.

Frequently asked questions

Is the ESP32 5V tolerant?

No. Its pins are 3.3V only. Use a voltage divider or level shifter for 5V signals.

Which pins should I avoid?

GPIO6-11 (flash), and the strapping pins GPIO0, 2, 5, 12 and 15 for sensors. GPIO34-39 are input-only.

Do the ESP32-C3 and S3 support Bluetooth Classic?

No. They are BLE-only. Only the original ESP32 runs Classic profiles such as SPP and A2DP.

ESP32 or ESP8266?

For new projects, the ESP32. It adds Bluetooth, more GPIO and a second core. The ESP8266 suits existing projects or the smallest Wi-Fi-only builds.

Guides

Reference pages on soldr.ai

More guides on soldr.ai

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