EQTrigger, EQ Based Relay Guitar Stomp Box

Phil Tucker made a EQTrigger, EQ Based Relay Guitar Stomp Box inspired by a post on HackaDay. He made it with the MSGEQ7, as the audio analyzing chip, and then connected the breakout board to an Arduino Nano. You can find sample code and a library linked from the DFRobot product page. He used a momentary switch to sample the desired threshold and then used that to compare the real-time input to.

Here's a video of how it works.

  Hardware List?

• Arduino Nano (or other Arduino)
• Audio Analyzer: MSGEQ7 (DFRobot DFR0126)
• Momentary Stomp Switch (for triggering sample record)
• Single Pull, Single Throw Latching Switch (for power on/off)
• Single Pull, Double Throw 5 volt relay
• 1/4″ mono audio jack (for audio input)
• A short extension cord to slice and connect to the relay
• LED for power indicator
• 220 ohm resistor for LED
• 10K ohm resistor for momentary switch pulldown
• 9 volt battery connector, or power adapter barrel jack
• Enclosure