DOIT ESPduino32

ESP32 dev board with Arduino Uno layout - combines Wi-Fi power with classic compatibility.

USB-B
DOIT ESPduino32 board
66 × 53.3 mm
ESP32
MCU
240MHz
clock
4MB
flash
520KB
SRAM
31· Two 12-bit, 18 Channels ADC
GPIO
BLE 4.2+ WiFi
radio
On this page

Pinout

35 pins · 2.54 mm pitch
View:
PinGPIOLabelsStatusCapabilitiesNotes
10IO0strapping-
21TX0PWMuart-
32LED_BUILTINIO2PWMstrapping-
43RX0PWMuart-
54IO4PWMstrapping-
65IO5PWMstrapping-
76CLKPWMstrapping-
87SD0PWMstrapping-
98SD1PWMstrapping-
109SD2PWMstrapping-
1110SD3PWMstrapping-
1211CMDPWMstrapping-
1312IO12PWMstrapping-
1413IO13PWMstrapping-
1514IO14PWMstrapping-
1615IO15PWMstrapping-
1716IO16PWMstrapping-
1817IO17PWMstrapping-
1918IO18PWMsafe-
2019IO19PWMsafe-
2121SDAPWMsafei2c
2222SCLPWMsafei2c
2323IO23PWMsafe-
2425IO25PWMsafe-
2526IO26PWMsafe-
2627IO27PWMsafe-
2732IO32PWMsafe-
2833IO33PWMsafe-
2935IO35strapping-
3036IO36strapping-
3139IO39strapping-
325SSstrappingspi
3323MOSIsafespi
3419MISOsafespi
3518SCKsafespi

Start with these

13 pins with no boot or system involvement
IO18PWMIO19PWMSDAPWMSCLPWMIO23PWMIO25PWMIO26PWMIO27PWMIO32PWMIO33PWMMOSIMISOSCK

Freely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.

Fine - with a little care

sampled at boot or shared with debug/serial
PinLabelWhat to knowRole
IO0GPIO0Must be HIGH during boot for normal startup; if held LOW on reset, forces flash programming mode.Strapping
LED_BUILTINGPIO2If driven HIGH on reset (while IO0 is LOW), selects an unsupported SDIO boot mode, causing boot failure.Strapping
IO4GPIO4Sampled at reset for boot config; should not be driven at boot (affects boot mode timing).Strapping
IO5GPIO5Must be HIGH during boot; if pulled LOW at reset, alters SDIO slave timing and may prevent normal boot.Strapping
IO12MTDI (GPIO12)Keep LOW during boot (internal PD); pulling HIGH at reset selects 1.8V flash mode, causing flash brownout if 3.3V flash is used.Strapping
IO13MTCK (GPIO13)Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed.Other
IO14MTMS (GPIO14)Used for JTAG debugging (TMS); driving it as GPIO may interfere with JTAG or produce spurious signals at boot.Other
IO15MTDO (GPIO15)Keep HIGH during boot (internal PU); if LOW on reset, bootloader log is silenced and boot mode may change.Strapping
IO35GPIO35Cannot be used as output; only suitable for input.Other
IO36GPIO36 (SENSOR_VP)Cannot be used as output; only suitable for input (e.g., analog read).Other
IO39GPIO39 (SENSOR_VN)Cannot be used as output; only suitable for input.Other
SSGPIO5Must be HIGH during boot; if pulled LOW at reset, alters SDIO slave timing and may prevent normal boot.Strapping

Only if you know the tricks

wired to flash or USB - expect a fight
PinLabelWhat to knowRole
TX0U0TXD (GPIO1)Connected to on-board USB-UART for uploading and logs; drives serial output at boot, so using as GPIO can disrupt programming or console.USB
RX0U0RXD (GPIO3)Used for receiving data from USB-UART (programming); also pulled HIGH at boot for console communication, so using as GPIO can disrupt uploads.USB
CLKGPIO6 (Flash SCK)Used for internal flash/PSRAM communication; not available for general GPIO.Flash
SD0GPIO7 (Flash SD0)Used for internal flash/PSRAM data; not available for general GPIO.Flash
SD1GPIO8 (Flash SD1)Used for internal flash/PSRAM data; not available for general GPIO.Flash
SD2GPIO9 (Flash SD2)Used by internal flash/PSRAM; typically not exposed on modules, avoid using as GPIO.Flash
SD3GPIO10 (Flash SD3)Used by internal flash/PSRAM; typically not exposed on modules, avoid using as GPIO.Flash
CMDGPIO11 (Flash CMD)Used by internal flash (chip select/command); not available for general use.Flash
IO16GPIO16Connected to internal PSRAM on PSRAM-enabled modules; not usable as GPIO on those modules.Flash
IO17GPIO17Connected to internal PSRAM on PSRAM-enabled modules; not usable as GPIO on those modules.Flash
These are recommendations, not hard rules - with the right pull-ups, timing and boot-state awareness most pins can be made to work. When in doubt, start green.
Pinout notes All 35 pins on the DOIT ESPduino32 are usable GPIO, spaced at the standard 2.54 mm pitch. Peripheral wiring is straightforward: I²C is mapped to SDA on GPIO21…

All 35 pins on the DOIT ESPduino32 are usable GPIO, spaced at the standard 2.54 mm pitch.

Peripheral wiring is straightforward: I²C is mapped to SDA on GPIO21 and SCL on GPIO22, while the SPI bus (MOSI, MISO, SCK, SS) is broken out in full.

12 of the exposed pins carry boot-time or system duties on the ESP32 (IO0, LED_BUILTIN, IO4 and 9 more) - check the guidance above before wiring anything to them. IO18, IO19, SDA, SCL and 9 more are free of any such role - the safest first picks.

Getting started

flash your first firmware in ~2 minutes
Tool:
1
Connect over USB
Uses a CH340 bridge - install the CH340 driver if no port appears. Not detected? Hold BOOT while plugging in.
2
Match & flash
Set the Tools options shown, then click Upload.
3
Verify it runs
The onboard LED on GPIO18 blinks - swap the pin if your board's LED differs.
Set these in Tools · leave everything else at default
Arduino IDE 2.x — Tools Copy
Board: "ESP32 Dev Module"
Flash Size: "4MB (32Mb)"
Flash Mode: "DIO"
Partition Scheme: "Default 4MB with spiffs (1.2MB APP / 1.5MB SPIFFS)" (default)
Upload Speed: "921600"
▸ every other Tools option — leave at default
Board: ESP32 Dev Module
Flash Size: 4MB (32Mb)
Flash Mode: DIO
Partition Scheme: Default 4MB with spiffs (1.2MB APP / 1.5MB SPIFFS)
Upload Speed: 921600
Find it: Tools ▸ Board ▸ ESP32 Arduino ▸ ESP32 Dev Module
blink.ino Copy
// blink the onboard LED
void setup() {
  pinMode(18, OUTPUT);
}
void loop() {
  digitalWrite(18, HIGH); delay(500);
  digitalWrite(18, LOW);  delay(500);
}
board to selectesp32dev⧉ copy
platformio.ini Copy
[env:esp32doit-espduino]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200
upload_speed = 921600
Find it: PlatformIO Home ▸ Boards, search esp32dev — or type it after board =.
board to selectesp32dev⧉ copy
device.yaml Copy
esp32:
  board: esp32dev
  variant: doitESPduino32
  framework:
    type: esp-idf

# blink - GPIO18
output:
  - platform: gpio
    pin: 18
    id: led_out
light:
  - platform: binary
    name: "LED"
    output: led_out
Find it: search ESPHome's board list for esp32dev (same ids as PlatformIO).
esptool doesn't pick board settings — a prebuilt .bin already has them baked in. This is just the raw flash command.
terminal Copy
esptool.py --chip esp32 --port /dev/ttyACM0 \
  --baud 921600 write_flash 0x0 firmware.bin
--port = your /dev/tty* (macOS/Linux) or COMx (Windows).
Build details: sketch space 1310720 B · data 327680 B · DIO

Specifications

ESP32 · 66 × 53.3 mm
Compute
MCU
ESP32
Clock
240 MHz
SRAM · Flash
520 KB · 4MB
Radio
Wi-Fi
802.11 b/g/n
Bluetooth
4.2 LE
Antenna
PCB
I/O
GPIO · ADC
31 · Two 12-bit, 18 Channels
UART · I²C · SPI
3 · 2 · 4
PWM
16 channels
Power
USB
USB-B
Serial
CH340
Boot address
0x1000
Flashing
Upload · OTA
esptool_py · esp_ota
Flash · Boot mode
DIO · DIO
Sketch · Data
1.25 MB · 320 KB
53.3 mm66 mm
66 × 53.3 mm · pin pitch 2.54 mm
The DOIT ESPduino32 uses esptool_py for firmware uploads, esp_ota for over-the-air (OTA) updates. Flash mode is DIO with DIO boot mode. The maximum sketch size is 1.25 MB with 320 KB available for data.

About this board

Inside sits the ESP32 - a dual-core Xtensa with both Bluetooth Classic and BLE.

With 31 GPIO broken out, you get more pins to play with than most ESP32 boards offer.

Around the module: Reset buttons.

Resources

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