No parts? No idea where to start? The Schematik Starter Kit fixes both. Reserve yoursReserve your Starter Kit

Gravity: IO Expansion Shield for Bluno M3 (DFR0371)

Gravity: IO Expansion Shield for Bluno M3 (DFR0371), DFRobot, DFR0371

Discontinued IO expansion shield for the Bluno M3, breaking out 39 color-coded GPIO pins including 8 PWM, 8 analog, 5 UARTs, 1 I2C, and 1 SPI. Voltage switchable between 3.3 V and 5 V; not compatible with other boards.

Pinout

Logical pinout · physical placement not verified
GRAVITY: IO EXPANSION Digital IO ports (0~38)External Power PortAnalog Input ports (0~7)3.3V5V SwitchUARTSReset ButtonI2CGNDSPIVCC (switched)Servo Power Port
  • Digital IO ports (0~38)
    Type · Signal
  • Analog Input ports (0~7)
    Type · Signal
  • UARTS
    Type · Signal
  • I2C
    Type · Signal
  • SPI
    Type · Signal
  • Servo Power Port
    Type · Power
  • External Power Port
    Type · Power
  • 3.3V5V Switch
    Type · Power, Control
  • Reset Button
    Type · Control
  • GND
    Type · Ground
  • VCC (switched)
    Type · Power

Start wiring

Shield

Confirm the data interface matches your host board.

Module pins: Servo Power Port, External Power Port, VCC (switched), GND, Digital I/O ports (0~38), Analog Input ports (0~7), UARTS, I2C. Schematik maps them to your board in the app.

Add-ons

269 other options

About 270 add-ons across Pi HATs, Arduino shields, and FeatherWings. The same function — motor control, PoE, display — usually ships once per host connector family. Get the host board right first.

View all 269

Related groups

4 groups

Arduino

About 75 boards across every Arduino generation: 5V Uno/Mega/GIGA, 3.3V MKR and Portenta, plus DFRduino and Bluno compatibles. Confirm the voltage rail before stacking any shield.

Boards · Arduino boards · 77 parts

ESP32

Wi-Fi and Bluetooth on a single chip, in every shape from Espressif DevKitC to Adafruit Feathers with STEMMA QT, DFRobot FireBeetles tuned for battery life, and Seeed XIAOs under a thumbnail.

Boards · ESP32 boards · 159 parts

Other MCUs

Specialists: Teensy for high-clock audio and USB, Adafruit SAMD boards running CircuitPython or the Arduino IDE, proper STM32 eval kits, and the micro:bit classroom ecosystem. Schematik builds target ESP32, Arduino Uno, and Pico; come here when you have a specific reason to.

Boards · Other MCU boards · 229 parts

Pi Pico

The Raspberry Pi MCU line — Pico, Pico 2, and third-party boards on the same silicon — plus a deep bench of Pico-pinout displays, loggers, and radio modules that do nothing without a Pico plugged in.

Boards · Pico & RP2040 boards · 43 parts