An NFC-Enabled Audio FX Center
This wall-mounted jukebox uses dual Raspberry Pi Zero boards for audio output and frequency display.
CircuitMonster’s son loves playing with electronic toys that have music and lights, but has medical needs that make it difficult for him to use them properly. As a solution, the electrical engineer likes to “create toys that can give him the sensory input he needs but encourage more intentional interaction.”
In this case he crafted an NFC FX Center, which senses the placement of blocks on a reader and plays a corresponding song. Visual output is provided by an RGB LED matrix that acts as a VU meter and three knobs are used to control a number of audio effects.
Beneath the FX Center’s nicely constructed wooden frame is a pair of Raspberry Pi Zero boards that power the system. One records audio using a USB microphone and calculates a frequency response to be shown on the LED visualizer, while the other plugs into a purpose-built PCB — described in more detail in this separate post. This PCB allows it to read NFC tags from the setup’s 3D-printed blocks and output sound through I2S amplifiers to the device’s speakers.
You can see the results in the first video below, as well as a view of the custom board in the second clip. Recorded audio is triggered via NFC, but the VU meter still responds to various other sounds, highlighting its dual-Pi design.