jackPiledmeter is a basic DPM (Digital Peak Meter) for the Jack Audio Connection Kit on the Raspberry Pi. It uses LEDs connected to GPIO pins to show audio levels.
Based on jackmeter - http://www.aelius.com/njh/jackmeter/ - by Nicholas J. Humfrey
This program uses the WiringPi library - http://wiringpi.com/ - by Gordon Henderson
EDIT 2024-06-06: WiringPi is now maintained by Grazer Computer Club. https://github.com/WiringPi/WiringPi
More info on how to run it and how to connect the LEDs to the RPi can be found on the Wiki https://github.com/RagnarJensen/jackPiledmeter/wiki Example
./jackPiledmeter system:capture_1
Registering as 'ledmeter'.
Connecting 'system:capture_1' to 'ledmeter:in'...