ESP32 classic: Pin mapping

[JanPetterMG]

🔧 ESP32: Pin Tips & Gotchas

🎉 Feel free to share your insights, questions, or setups below!

💡 This thread is for beginners and experienced users alike. Whether you're figuring out your first build or have clever tricks to share, you're welcome to join in.

---

⏰ RTC Pins

GPIO 4, 13, 14, 25–39 can wake the ESP32 from deep sleep. Useful for:

• Power button PIN_SW1
• Mode button PIN_SW2
• Interrupts like PIN_INT from a real-time clock

🎙️ Analog Input

GPIO 32–39 are usable as analog inputs. For example:

• PIN_LDR for photocell signals
• PIN_MIC for microphone signals

⚠️ Avoid Strapping Pins

GPIO 0, 2, 5, 12, 15 have bootstrapping functions. Avoid connecting these to inputs that may float or pull them during boot.

📄 Reference

ESP32 Datasheet (PDF)

---

💬 Add your own:

• Board name
• Pinout overview
• Tips or pitfalls you encountered
• Questions or confusions you had as a beginner

Feel free to include your SPI, PWM, I2C, or other digital pin setups too—this thread is meant to cover practical pin mapping across different ESP32 boards.

Let’s make this a helpful resource together!

[JanPetterMG]

WeMos LOLIN D32 PRO

📍 Pinout Diagram

Hardware Overview

// IKEA Frekvens
#define PIN_OE 4    // TF-CS EN
#define PIN_CS 5    // SS    LAK
#define PIN_SW1 13  //       SW1
#define PIN_SW2 14  // T-CS  SW
#define PIN_SCLK 18 // SCK   CLK
#define PIN_MOSI 23 // MOSI  DA
#define PIN_MIC 34  // A     U3 pin 7

// IKEA Obegränsad
#define PIN_OE 4    // TF-CS EN
#define PIN_CS 5    // SS    CLA
#define PIN_SW2 13  //       SW
#define PIN_SCLK 18 // SCK   CLK
#define PIN_MOSI 23 // MOSI  DI

⚡ Power Notes

• USB: Power input pin, supports 2 V to 6.0 V
• GND: Ground reference
• 3V: Logic-level power output for peripherals (e.g. level shifters)

The USB pin must not be confused with the USB port.