PiAware Data Display

After setting up my PiAware receiver to track live flight data, I wanted a simple way to glance at some key stats without SSH-ing into the Pi or opening a browser. Enter the humble 20x4 I2C LCD screen.

This post walks through how I wired up a character LCD to my Raspberry Pi, wrote some Python to pull flight data from PiAware, and got a tiny dashboard updating every second—all without needing to touch a GUI.

What I Used

• Raspberry Pi running PiAware
• 20x4 I2C character LCD (HD44780-compatible with PCF8574 backpack)
• Python 3 and the RPLCD library
• All my patientce until I figure out I needed to adjusting the contrast screw on the LCD

Wiring It Up

This part was pretty straightforward:

• VCC → Pi 5V pin
• GND → Pi GND pin
• SDA → Pi SDA (GPIO 2)
• SCL → Pi SCL (GPIO 3)

Then I ran raspi-config to enable I2C under Interfacing Options. I also installed the RPLCD library with:

pip install RPLCD

The code

You can find the full python script here: https://gist.github.com/filbot/0e98902e0be5b642649541b9df85aaa3

What It Displays

The screen shows four lines, updated every second:

• Current ADS-B messages per second
• Peak observed ADS-B rate
• CPU temperature
• System uptime

Everything is pulled from system files or from PiAware’s aircraft.json, which lives at /run/dump1090-fa/aircraft.json. Here’s a sample of what the display looks like:

ADS-B:       42 msg/s
PEAK:       109 msg/s
CPU TEMP:       49.7C
UPTIME:      00:17:42

The full script polls every second, tracks message rate over time, and updates the display with a minimal refresh. One thing that tripped me up early on was contrast—if you don’t see anything on your screen, it might not be your code. A tiny flathead screwdriver and a half-turn of the potentiometer made all the difference.

Extra Credit: Run It on Boot

If you want your LCD dashboard to start automatically when the Pi powers on, you can turn your Python script into a systemd service. Here’s how to do it.

1. Create a service file

First, create a new file called lcd-display.service:

sudo nano /etc/systemd/system/lcd-display.service

Paste this into the file (update the paths to match where your script lives):

[Unit]
Description=PiAware LCD Display
After=network.target

[Service]
ExecStart=/usr/bin/python3 /home/pi/lcd-display.py
WorkingDirectory=/home/pi
StandardOutput=inherit
StandardError=inherit
Restart=always
User=pi

[Install]
WantedBy=multi-user.target

Make sure your script is executable and the path to python3 is correct (you can run which python3 to verify).

2. Enable and start the service

Run the following commands:

sudo systemctl enable lcd-display.service
sudo systemctl start lcd-display.service

Now the display should update automatically every time the Pi boots up.

To check on the status or debug output:

sudo journalctl -u lcd-display.service -f

Bonus Tip

If you’re still actively tweaking the script, you can stop the service temporarily with:

sudo systemctl stop lcd-display.service

Then run your script manually as usual. Just don’t forget to restart the service when you’re done!