A Step-by-Step Guide on Connecting Raspberry Pi to Pixhawk for Drone Development and Automation

Learn how to connect a Raspberry Pi to Pixhawk using MAVLink, the standard messaging protocol for drone communications. This guide will help you set up your Raspberry Pi for drone development and auto …


Updated October 18, 2023

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Learn how to connect a Raspberry Pi to Pixhawk using MAVLink, the standard messaging protocol for drone communications. This guide will help you set up your Raspberry Pi for drone development and automation projects.

Raspberry Pi has become a popular choice among hobbyists and developers working on drones and autonomous vehicles due to its low cost, versatility, and powerful processing capabilities. Pixhawk is the most widely used autopilot board for drones, and it uses MAVLink as the standard messaging protocol for drone communications. In this article, we will explore how you can connect your Raspberry Pi to a Pixhawk using MAVLink.

Prerequisites

Before you begin, make sure you have the following:

  1. A Raspberry Pi (any model) with Raspbian OS installed and updated.
  2. A Pixhawk autopilot board (either original or compatible).
  3. A USB-to-TTL cable to connect the Raspberry Pi to Pixhawk’s TELEM2 port.
  4. An Ethernet cable or Wi-Fi adapter for network connection between the Raspberry Pi and Pixhawk.
  5. (Optional) A GPS module for better positioning data.
  6. Basic knowledge of Python, MAVLink, and drone flight control systems.

Setting Up Raspbian OS on Raspberry Pi

If you haven’t already done so, download the latest version of Raspbian from the official website: https://www.raspberrypi.org/downloads/raspbian/. Then, follow the instructions to write the image to your SD card and set up your Raspberry Pi.

To communicate with Pixhawk using MAVLink, you need to install the required libraries on your Raspberry Pi. Open a terminal window and run the following commands:

sudo apt-get update && sudo apt-get upgrade
sudo apt-get install python3-pip python3-dev python3-mavlink python3-serial python3-lxml

This will install all necessary libraries, including MAVLink, PySerial, and lxml.

Connecting Raspberry Pi to Pixhawk

  1. Connect the USB-to-TTL cable to your Raspberry Pi’s TX (transmit) pin and Pixhawk’s TELEM2 port. The other end of the cable should be connected to a ground pin on your Pixhawk.
  2. Connect an Ethernet cable or Wi-Fi adapter between your Raspberry Pi and Pixhawk for network communication. Make sure both devices are on the same network.
  3. (Optional) If you want to use GPS data, connect a GPS module to the Pixhawk’s GPS port.
  4. Power on your Pixhawk and Raspberry Pi. You should see a blinking LED on the Pixhawk indicating that it is running correctly.

Writing Python Code to Connect Raspberry Pi to Pixhawk

Now, you need to write some Python code to connect your Raspberry Pi to Pixhawk and receive data from it. Here’s an example script:

import socket
from pymavlink import mavutil

# Set up MAVLink connection
mav = mavutil.mavlink_connection('udpout:192.168.1.100:14550') # Replace with Pixhawk's IP address and MAVLink port number

while True:
    # Request data from Pixhawk
    mav.mav.command_long_send(
        mav.target_system,  # target system (Pixhawk) ID
        1,               # target component (autopilot) ID
        mavutil.mavlink.MAV_CMD_REQUEST_DATA_STREAM,  # command ID
        0,              # stream period in milliseconds (0 for a one-time request)
        mavutil.mavlink.MAVLINK_MSG_ID_HIGHRES_IMU,  # requested data message ID
        1,              # request all fields of the message (1) or only specific fields (0)
        0, 0, 0         # parameter 3-5 are not used for this command
    )

    # Receive and print data from Pixhawk
    msg = mav.recv_match(blocking=True)
    if msg is not None:
        print(msg)

This script will connect to Pixhawk using UDP (replace '192.168.1.100' with your Pixhawk’s IP address), request data from the high-resolution IMU sensor, and print it out in real time. You can modify this script to send commands to Pixhawk or receive other types of data by changing the message ID and parameters accordingly.

Conclusion

Congratulations! You have successfully connected your Raspberry Pi to a Pixhawk autopilot board using MAVLink. This is just the beginning, and you can now start developing more complex applications for drone development and automation. Remember to explore other MAVLink messages and features to expand your capabilities. Good luck!