ESP32 Quick Reference
ESP32 Quick Reference
Board setup, IDE config, boot modes, and MicroPython basics.
IDE Setup
| Boards Manager URL | https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_index.json |
| Board: ESP32 Dev Module | Standard choice for most 30-pin DevKit boards |
| Upload Speed: 921600 | Fastest reliable upload rate for most boards |
| Flash Size: 4MB | Match to your module ߀” check the module label |
Boot & Reset
| BOOT button (GPIO 0) | Hold during reset to enter download mode for uploading |
| EN button | Hard reset the ESP32 ߀” restarts the running sketch |
| GPIO 0 HIGH at boot | Normal run mode ߀” your sketch starts |
| GPIO 0 LOW at boot | Firmware download mode ߀” ready to receive a new sketch |
MicroPython
| from machine import Pin | Import the Pin class for GPIO control |
| Pin(2, Pin.OUT) | Create an output pin on GPIO 2 |
| pin.value(1) | Set pin HIGH |
| from time import sleep | Import sleep for delays (in seconds) |
Pin Restrictions
| GPIO 6߀“11: AVOID | Connected to internal flash ߀” using them will crash the board |
| GPIO 34߀“39: Input only | No internal pull-up or pull-down ߀” read only |
| GPIO 0: Boot pin | Has pull-up; avoid driving LOW at reset time |
| 3.3 V logic only | All ESP32 pins are 3.3 V ߀” never connect 5 V signals directly |