The idea for this device came to me while watching "Tales from the Loop," an Amazon series I love. In the seventh episode, George's muscle electrical activity is measured on the stump of his upper arm in order to readjust his outdated robotic prosthetic hand. Since the series is mostly set in the 80s, the color scheme of the device is kept appropriate.

The device

Building and demonstration video

Schematics

Example code

#include <Adafruit_NeoPixel.h>
#define PIN        6  
#define NUMPIXELS 24 // NeoPixel ring size
Adafruit_NeoPixel pixels(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);
#define DELAYVAL 5 // Time (in milliseconds) to pause between pixels
int triggerVal = 344;

void setup() {
  pixels.begin(); 
}

void loop() {
  pixels.clear(); 
  int sensorValue = analogRead(A0);
    if(sensorValue >= triggerVal) {
      for(int i=0; i<200; i++) { 
        int randPixel = random(0, 24);
        int randR = random(0, 256);
        int randG = random(0, 256);
        int randB = random(0, 256);
        pixels.setPixelColor(randPixel, pixels.Color(randR, randG, randB));
        pixels.setBrightness(255);
        pixels.show();   
        delay(DELAYVAL); 
    }
  } else {
  pixels.clear(); 
  pixels.show();
  } 
}