// https://forum.arduino.cc/t/converting-2-digit-multiplexed-7-segment-led-signal-to-128-x-64-oled-using-arduino-nano/1129222
// https://wokwi.com/projects/365887839415838721

// https://docs.arduino.cc/hacking/software/PortManipulation
// https://www.arduino.cc/reference/en/language/functions/external-interrupts/attachinterrupt/

const byte ledPin = 7;
const byte interruptPin = 2;
volatile byte state = LOW;

unsigned char iGlag;

void setup() {
  Serial.begin(115200);
  Serial.println("breakfast oscilloscope v0.0\n");

  pinMode(ledPin, OUTPUT);
  pinMode(interruptPin, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(interruptPin), blink, CHANGE);

  DDRB  &= 0b11100000;   // inputs 8 to 12
  PORTB |= 0b00011111;   // weak pullup
}


// watch for either edge
// wait a bit and grab 8 - 12 inputs
// when you've seen both edges, print a report about them
// reset and repeat

// In this simulation, bouncing on the switch has been turned off!
// we do not expcet bouncing on the observed signals

unsigned char edgesSeen;
unsigned char portOnEdge[2];   // 0 - rising edge, 1 - falling edge

void loop() {
  digitalWrite(ledPin, state);

  if (iGlag) {
    unsigned char onPortB = PINB;
    iGlag = 0;    // clear the flag
    delayMicroseconds(15);    // why not?

    if (digitalRead(interruptPin)) {
      portOnEdge[0] = PINB & 0b00011111;
    }
    else {
      portOnEdge[1] = PINB & 0b00011111;
    }
    edgesSeen++;
  }

  if (edgesSeen >= 2) {
    Serial.print("segments after clock rises ");
    Serial.println(portOnEdge[0], BIN);

    Serial.print("segments after clock fallls ");
    Serial.println(portOnEdge[1], BIN);

    Serial.println();

    edgesSeen = 0;
  }
}

void blink() {
  state = !state;
  iGlag = 1;      // set the flag 
}