Arduino Adafruit Feather-M4 ADC example

feather-M4-adc.ino

int sensorPin = A2;    // select the input pin for the potentiometer

const uint8_t D12 = 12;
const uint8_t D11 = 11;
const uint8_t D10 = 10;
const uint8_t D9  = 9;
const uint8_t D6  = 6;
const uint8_t D5  = 5;
const uint8_t D21 = 21;
const uint8_t D22 = 22;

void setup() {
  Serial.begin(115200);

  pinMode(D12, OUTPUT);
  pinMode(D11, OUTPUT);
  pinMode(D10, OUTPUT);
  pinMode(D9, OUTPUT);
  pinMode(D6, OUTPUT);
  pinMode(D5, OUTPUT);
  pinMode(D21, OUTPUT);
  pinMode(D22, OUTPUT);

}

void loop() {
  int sensorValue = analogRead(sensorPin);    

  Serial.println(sensorValue);

  delay(100); // Give time for ADC to settle
  
  // 120->925
  int m = (int)((sensorValue-110) / 104);

  Serial.print("m: ");
  Serial.println(m);

  digitalWrite(D12, LOW);
  digitalWrite(D11, LOW);
  digitalWrite(D10, LOW);
  digitalWrite(D9, LOW);
  digitalWrite(D6, LOW);
  digitalWrite(D5, LOW);
  digitalWrite(D21, LOW);
  digitalWrite(D22, LOW);

  // Note: It seems that pins 21 and 22 are miss labled on the feather-m4
  // pinout diagram.
  switch (m) {
    case 0: digitalWrite(D12, HIGH); break;
    case 1: digitalWrite(D11, HIGH); break;
    case 2: digitalWrite(D10, HIGH); break;
    case 3: digitalWrite(D9, HIGH); break;
    case 4: digitalWrite(D6, HIGH); break;
    case 5: digitalWrite(D5, HIGH); break;
    case 6: digitalWrite(D22, HIGH); break;   // The pinout says this should 21
    case 7: digitalWrite(D21, HIGH); break;
  }
}

A very simple ADC example.
When you turn the Pot it turns on different LEDs