Overview

Based on the ESP32-WROOM-32/ESP32-WROOM-32D module with built-in WiFi and Bluetooth capabilities. Has built-in antenna.

Additonal Hardware features:

• Boot & Reset buttons - Boot button can be used, inverted on GPIO00
• LED on GPIO02

Test Status

• ✅ Basic Config + Internal LED & Boot Button
• ✅ GPIO - output: Internal LED, input: Boot Button
• UART
• SPI
• I2C
• I2S
• (LED) PWM
• IR
• ADC
• Touch Sensor
• DAC
• SD Card

Basic Configuration

Basic configuration with built in button and LED.

esphome:
  name: my-esp32dev

esp32:
  board: esp32dev
  framework:
#    type: arduino
    type: esp-idf

output:
  - platform: gpio
    pin: GPIO02
    id: builtin_led

light:
  - platform: binary
    name: "Built in LED"
    output: builtin_led

binary_sensor:
  - platform: gpio
    pin: 
      number: GPIO00
      inverted: true
    id: boot_btn
    on_press:
      then:
        - output.turn_on: builtin_led
    on_release:
      then:
        - output.turn_off: builtin_led

HW-463 Variant

• USB-to-UART: CP2102
• Module: ESP32-WROOM-32
• CPU: ESP32 (ESP32-D0WDQ6 - Dual Core)
• USB: Micro-USB

HW-394 Variant

• USB-to-UART: CH340G
• Module: ESP32-WROOM-32D - newer and slightly better than ESP32-WROOM-32
• CPU: ESP32 (ESP32-D0WD - Dual Core)
• USB: USB-C

Module Specifications

• Module: ESP32-WROOM-32
• CPU: Xtensa dual-core 32-bit LX6 CPU, frequency up to 240MHz
• RAM: 520KB SRAM (320KB usable)
• Flash: 4MB
• WiFi: 802.11 b/g/n
• Bluetooth: v4.2 BR/EDR and BLE
• Operating Voltage: 3.3V
• Input Voltage: 5V (via USB or VIN)
• GPIO Pins: Up to 32
  • 5 strapping GPIOs
  • 6 GPIOs need for flash/PSRAM
• ADC: 2*12-bit ADC (up to 18 channels)
• PWM: 16 channels
• I2C: 2 interfaces
• I2S: 2 interfaces
• SPI: 4 interfaces
• UART: 3 interfaces

Board Pinout

The ESP32 DevKit V1 has 30 pins in total:

Power Pins

• 3.3V - 3.3V output (AMS1117 3.3)
• GND - Ground pins (x2)
• VIN - Input voltage (5-12V) or 5V output from USB (when powered via USB)
• EN - Enable pin (reset when pulled low)

GPIO Pins

• GPIO0-GPIO39 - General purpose I/O
  • GPIO34-39 are input-only
  • GPIO6-11 are connected to flash (don’t use)
  • Some pins have boot mode constraints (GPIO0, GPIO2, GPIO12, GPIO15)

Special Function Pins

Check out https://documentation.espressif.com/esp32_datasheet_en.pdf IO_MUX table for which pins can be used for what because a lot of them are multiplexed.

• Touch Sensors: GPIO0, GPIO2, GPIO4, GPIO12-15, GPIO27, GPIO32-33
• I2C: By default GPIO21=SDA, GPIO22=SCL
• SPI: By default GPIO23=MOSI, GPIO19=MISO, GPIO18=SCK, GPIO05=CS
• DAC: Dual 8-bit DAC outputs: GPIO25 and GPIO26
• Analog & Touch: see pinout, many GPIOs can be used as ADC1 and ADC2 input, capacitive-touch sensors and LED/Motor PWM signals

Other interfaces: SD card, UART, SDIO, I2C, I2S, IR, pulse counter, CAN

Important Notes

⚠️ Boot Mode Pins: Be careful with GPIO0, GPIO2, GPIO12, and GPIO15 during boot. These affect boot mode selection.

⚠️ Input-Only Pins: GPIO34-39 can only be used as inputs and don’t have internal pull-up/pull-down resistors.

⚠️ ADC2 Limitation: Some ADC2 pins cannot be used when WiFi is active.

⚠️ Strapping Pins: Some pins are used during boot and may cause issues if connected to certain peripherals.

Troubleshooting

Board won’t flash:

• Hold the BOOT button while connecting USB (I had this issue with CP2102 variant, I had to hold BOOT button)
• Try a different USB cable (must support data)
• Check that CH340/CP2102 drivers are installed

Random resets:

• Check power supply (needs stable 5V, 500mA+)
• Add capacitors near power pins if using long wires
• Avoid connecting high-current devices directly

Other Images

HW-463 version:

HW-463 version - back: