D-duino-32
ESP32 dev board with built-in OLED - perfect for compact UIs, debugging, and quick visual feedback.
D-duino-32 Pinout
16 pins| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | 0 | A11T1D3 | strapping | adc · touch | |
| 2 | 1 | TXD10PWM | uart | uart | |
| 3 | 2 | A12T2D4PWM | strapping | adc · touch | |
| 4 | 3 | RXD9PWM | uart | uart | |
| 5 | 4 | SCLA10T0D2PWM | safe | adc · touch · i2c | |
| 6 | 5 | SDAD1PWM | strapping | i2c | |
| 7 | 12 | MISOA15T5D6PWM | strapping | adc · touch · spi | |
| 8 | 13 | MOSIA14T4D7PWM | strapping | adc · touch · spi | |
| 9 | 14 | SCKA16T6D5PWM | strapping | adc · touch · spi | |
| 10 | 15 | SSA13T3D8PWM | strapping | adc · touch · spi | |
| 11 | 25 | A18DAC1PWM | safe | adc · dac | |
| 12 | 26 | A19DAC2PWM | safe | adc · dac | |
| 13 | 36 | A0 | strapping | adc | |
| 14 | 39 | A3 | strapping | adc | |
| 15 | - | OLED_SCL | safe | - | |
| 16 | - | OLED_SDA | safe | - |
Start with these
3 pins with no boot or system involvementFreely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.
Fine - with a little care
11 pins · 11 things to knowA11GPIO0 Bootstrapping pin (enter bootloader when low); internal pull-up. Strapping
Must be HIGH during boot for normal startup; if held LOW on reset, forces flash programming mode.
TXGPIO1 Default UART0 TX pin for USB-serial programming and console. UART
Connected to on-board USB-UART for uploading and logs; drives serial output at boot, so using as GPIO can disrupt programming or console.
A12GPIO2 Bootstrapping pin (must be low or floating at reset); internal pull-down. Strapping
If driven HIGH on reset (while IO0 is LOW), selects an unsupported SDIO boot mode, causing boot failure.
RXGPIO3 Default UART0 RX pin for USB-serial programming (console input). UART
Used for receiving data from USB-UART (programming); also pulled HIGH at boot for console communication, so using as GPIO can disrupt uploads.
SDAGPIO5 Bootstrapping pin; internal pull-up; VSPI CS0 (default SPI chip-select); acts as FSPIWP (flash write-protect) on internal-flash variants. Strapping
Must be HIGH during boot; if pulled LOW at reset, alters SDIO slave timing and may prevent normal boot.
MISOGPIO12 Bootstrapping pin; JTAG TDI; sets flash voltage (VDD_SDIO); also HSPIQ (flash data line). Strapping
Keep LOW during boot (internal PD); pulling HIGH at reset selects 1.8V flash mode, causing flash brownout if 3.3V flash is used.
MOSIGPIO13 JTAG clock pin (TCK); also ADC2 channel 4 / Touch4 input. JTAG
Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed.
SCKGPIO14 JTAG mode select pin (TMS); also HSPI CLK and PWM-capable GPIO. JTAG
Used for JTAG debugging (TMS); driving it as GPIO may interfere with JTAG or produce spurious signals at boot.
SSGPIO15 Bootstrapping pin; JTAG TDO; controls UART0 boot log output; also HSPICS0 (secondary SPI CS). Strapping
Keep HIGH during boot (internal PU); if LOW on reset, bootloader log is silenced and boot mode may change.
A0GPIO36 Input-only GPIO (no output); ADC1 channel 0, Hall sensor VP. Other
Cannot be used as output; only suitable for input (e.g., analog read).
A3GPIO39 Input-only GPIO (no output); ADC1 channel 3, Hall sensor VN. Other
Cannot be used as output; only suitable for input.
Across 16 pins, the D-duino-32 exposes 14 GPIO.
For peripherals, I²C is mapped to SDA on GPIO5 and SCL on GPIO4; the SPI bus (MOSI, MISO, SCK, SS) is broken out in full; TX/RX on GPIO1 and GPIO3 cover serial logging and flashing.
On the analog side there are 11 ADC-capable pins for sensors and battery monitoring, 7 capacitive-touch inputs and 2 true DAC outputs.
If you want zero surprises, SCL, A18 and A19 are free of any such role - the safest first picks. 11 of the exposed pins carry boot-time or system duties on the ESP32 (A11, TX, A12 and 8 more).
Getting started
flash your first firmware in ~2 minutesBoard: 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
// toggle GPIO4 - wire an LED and resistor to it
void setup() {
pinMode(4, OUTPUT);
}
void loop() {
digitalWrite(4, HIGH); delay(500);
digitalWrite(4, LOW); delay(500);
}[env:d-duino-32]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200
upload_speed = 921600esp32dev - or type it after board =.esp32:
board: esp32dev
variant: esp32
framework:
type: esp-idf
# blink - GPIO4
output:
- platform: gpio
pin: 4
id: led_out
light:
- platform: binary
name: "LED"
output: led_outesp32dev (same ids as PlatformIO).esptool.py --chip esp32 --port /dev/ttyACM0 \
--baud 921600 write_flash 0x1000 firmware.bin--port = your /dev/tty* (macOS/Linux) or COMx (Windows).Specifications
ESP32 · vs other ESP32 chips →About this board
At its core is the ESP32 - a dual-core Xtensa with both Bluetooth Classic and BLE.
Only 14 GPIO are broken out, where most ESP32 boards manage about 24 - worth checking the pinout covers what you need.
Onboard you'll find an OLED 0.96" 128x64 display and Reset/Boot buttons.
Resources
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