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!