Drone Pi: A Dual‑Mode Multiwii & Raspberry Pi Quadcopter for Smartphone and Remote Control

NOTE: THIS INSTRUCTABLE IS BEING WRITTEN

This guide documents a quadcopter that combines a Multiwii flight controller with a Raspberry Pi 2 B. Its standout feature is the ability to pilot the aircraft either with a conventional RC transmitter or via a smartphone app.

The Multiwii handles motor power distribution and flight stability, while the Raspberry Pi receives commands from the phone, forwards them to the Multiwii, and streams camera data. A Pi‑Camera mounted on the front records Full‑HD video or stills, saving media to a USB key.

The frame is assembled from recycled materials, a challenge that demonstrates how to build a functional aircraft even with heavier-than‑standard components.

We’re a group of young French students who created this drone for the first time. We used online tutorials and Instructables as a foundation, and now we share our complete build with you. Enjoy!

Step 1: Parts

To assemble the quadcopter you’ll need the following components:

• Frame – Build or purchase a 0.45 m X‑shaped frame with three central levels for the Raspberry Pi, Multiwii, battery, and ESCs.
• 4 motors (16€) – Turnigy brushless motors. Link
• 4 ESCs (10€) – Hobbyking 30A ESCs. Link
• Battery (27,5€) – Turnigy 3S 3300 mAh. Link
• Battery monitor (4€) – Hobbyking 3S battery monitor. Link
• Power distribution board (4€) – Hobbyking quadcopter power distribution board. Link
• Connectors 3.5 mm (4,5€) – For ESC–motor connections. Link
• Connectors 4.5 mm (4,33€) – For new distribution board connectors. Link
• Propellers (5€) – 10 × 4.5 SF props for a 40 cm frame. Link
• Multiwii (49€) – CRIUS AIO PRO Multiwii flight controller.
• Mounting pad (2€) – Vibration‑damping pads for the Multiwii. Link
• Raspberry Pi 2 B (35€) – Handles wireless communication and command forwarding.
• Pi camera (19€) – Front‑mounted camera for Full‑HD video and photos.
• Wifi key (9€) – Enables the Pi to create a private Wi‑Fi network.
• USB key – For storing recorded video.
• Remote control + RC receiver – Optional; connects to the Multiwii for traditional piloting.

Weld the connectors to the ESC wires, motor wires, and distribution board wires before mounting.

Step 2: How It Works

Multiwii – The open‑source flight controller based on Arduino. It translates pitch, roll, yaw, and throttle commands into ESC pulse widths, keeping the aircraft stable. We use the CRIUS AIO PRO V2, a popular variant with a robust community.

Raspberry Pi – On boot, the Pi creates a private Wi‑Fi hotspot with a DHCP server, providing the smartphone with an IP address. A custom Python script launches a WebSocket server that receives real‑time control commands from the phone app. The same script opens a serial connection to the Multiwii, forwarding those commands. Source code is available on GitHub: Multiwii‑Raspberry‑Drone‑Server.

Application – The app is built with Cordova using HTML, CSS, and JavaScript, making it cross‑platform (Android, iOS, etc.). It establishes the WebSocket connection to the Pi and renders a standard controller interface. Code can be found here: QuadcopterControl.

Step 3: The Frame

The 0.45 m X‑shaped frame provides a stable platform suitable for camera work rather than racing. Three mounting levels allow you to position the Raspberry Pi, Multiwii, ESCs, and battery efficiently. We designed a top platform for the Multiwii (with the Pi beneath) and a lower platform for the battery, making maintenance and battery swapping straightforward. Despite being constructed from recycled parts, the frame’s weight remains within the motors’ capacity.

Step 4: Propulsion

1. Wire each motor to its ESC, respecting the color code. Reverse a motor’s connection to change propeller rotation if needed (consult the wiring diagram). Keep propellers off until the system is safe.

2. Connect the ESCs to the power distribution board, observing correct polarity.

3. Once wiring is verified, mount the components onto the frame.

4. If the motor screws are too small for the propellers, enlarge them accordingly (see our photos).

For further details, refer to the complete build guide.