Control Raspberry Pi via USB connected Android device

Introduction

This article guides you through connecting your Raspberry Pi to an Android device via USB and establishing communication for remote control. We’ll cover essential tools and methods, enabling you to manage your Raspberry Pi from the convenience of your smartphone or tablet.

Prerequisites

• Raspberry Pi with Raspbian or a compatible OS installed.
• Android device with USB OTG (On-The-Go) capability.
• USB cable for connecting the Raspberry Pi and Android device.
• Basic understanding of command-line interfaces (CLI).

Setting Up the Raspberry Pi

Install Necessary Packages

On your Raspberry Pi, use the following commands to install the required software:

sudo apt update
sudo apt install python3-serial

Configure Serial Port

Open the configuration file for serial ports:

sudo nano /boot/config.txt

Add the following line to enable the serial port:

enable_uart=1

Save and exit the file.

Start the Serial Server

Create a Python script to run a simple serial server:

sudo nano serial_server.py

Paste the following code into the file:

import serial
import time

# Configure serial port
port = "/dev/ttyACM0"  # Replace with your actual port if needed
baudrate = 115200

# Create serial object
ser = serial.Serial(port, baudrate)

while True:
    # Read data from serial port
    data = ser.readline().decode('utf-8').rstrip()
    
    # Print received data (optional)
    print(f"Received: {data}")

    # Send response (optional)
    ser.write(b"Hello from Raspberry Pi!\n")

    time.sleep(1)

Save and exit the file. Then, run the script in the background:

python3 serial_server.py &

Setting Up the Android Device

Install a Terminal Emulator

Download and install a terminal emulator app from the Play Store, such as:

• Termux
• ConnectBot
• AndroTerm

Connect to Raspberry Pi via USB

Connect your Android device to the Raspberry Pi using the USB cable. Ensure that your Android device has USB OTG enabled.

Establish Serial Connection

Open the terminal emulator app and run the following command (replace /dev/ttyACM0 with the actual device path if needed):

screen /dev/ttyACM0 115200

Controlling the Raspberry Pi

Once the connection is established, you can send commands to the Raspberry Pi using the terminal. Here’s an example:

ls

This command will list the files and directories in the Raspberry Pi’s current directory. You can also run other commands like:

• pwd – Print working directory
• cd /path/to/directory – Change directory
• sudo apt update – Update package lists
• sudo apt install [package_name] – Install a package

Tips and Troubleshooting

• If the connection fails, ensure that the serial port is correctly configured on both the Raspberry Pi and Android device.
• Check the USB cable and ensure it’s properly plugged in at both ends.
• Verify that your Android device has USB OTG enabled in the settings.
• Consult the documentation of your terminal emulator for specific commands and options.

Conclusion

Controlling your Raspberry Pi remotely using a USB-connected Android device offers flexibility and convenience. By following these steps, you can manage your Raspberry Pi projects from the comfort of your smartphone or tablet.