hackday radio hardware code

radio1.pde

int LED = 11;
int SWITCH = 10;
// int VOLUME = A1;
int KNOB0 = 9;
int KNOB1 = 8;


// 00 -> 10 -> 11 -> 00

int knobstate = 0;
int switchstate = 0;

long nextbeat = 0;
long tempo = 120;
long timedelay = 1000 / 120;
long lightoff = 0;

void setup() {
  pinMode(LED, OUTPUT);
  pinMode(SWITCH, INPUT);
  pinMode(KNOB0, INPUT);
  pinMode(KNOB1, INPUT);
  Serial.begin(9600);
  updatetempo();

  for (int i=0; i<4; i++) {  
    digitalWrite(LED, 1);
    delay(150);
    digitalWrite(LED, 0);
    delay(150);
  }
}

void updatetempo() {
  timedelay = 60000 / tempo; 
  nextbeat = millis() + timedelay;
  Serial.print("timedelay=");
  Serial.print(timedelay);
  Serial.print("\n");
}

char buf[100];
int bp = 0;

void loop() {
  
  if (Serial.available()) {
    char c = Serial.read();
    if (c == '\n') {
      // parse
      if (strncmp(buf, "bpm=", 4) == 0) {
        tempo = atoi(buf+4);
        updatetempo();
      }
      bp = 0;
      memset(buf, 0, 100);
    } else {
      buf[bp++] = c;
    }
    
  }
  
  int knob = digitalRead(KNOB0)*2 + digitalRead(KNOB1);
  if (knob != knobstate) {
    if (knob == 0 && knobstate == 1) { Serial.print("knob-up\n"); }
    if (knob == 1 && knobstate == 0) { Serial.print("knob-down\n"); }

    knobstate = knob;
  }
  
  int sw = digitalRead(SWITCH);
  if (sw != switchstate) {
    if (sw == 1) { Serial.print("switch-off\n"); }
    if (sw == 0) { Serial.print("switch-on\n"); }
    switchstate = sw;
  }
  
  if (millis() > nextbeat) {
     // Serial.print("beat\n");
     // Serial.println(timedelay);
     // Serial.println("\n");
     nextbeat = millis() + timedelay;
     digitalWrite(LED, 1);
     lightoff = millis() + 20;
  };
  
  digitalWrite(LED, millis() < lightoff);
  
  delay(1); 
}