Deepstomp, a DIY Digital Multi-Effect Stomp Box - Hackster.io
Amazon.com: D'Addario Guitar Tuner Pedal - Chromatic Tuner for Electric Guitars, Bass Guitars and More - Rugged Aluminum Enclosure - Fast and Accurate - True Bypass with Full Color Display : Everything Else
Tech Talk: How to eliminate rough or sharp edges on tuner posts | Guitar.com | All Things Guitar
3 Ways to Tune a Guitar Without a Tuner - wikiHow
First build: simple atmega8 based tuner pedal : r/diypedals