   //PORTD |= 0b00000100;
 
   pinMode(d2, INPUT); // listening pin
+  // PORTD |= 0b01000000; // the listening pin is mapped to bit 6
 
   // start the input pin off (meaning the bus is high, normal state)
   PORTD &= 0b11111011;


void sendBytes() {
    while (!q.isEmpty()) {
        sendByteOnPin(q.dequeue());
        // wait for low then high (for a zero)
        while (digitalRead(d2) == 1) {
          // busy
        }
        while (digitalRead(d2) == 0) {
          // busy
        }
    }

  }
}

inline void sendByteOnPin(int command) {
    // This will actually send 10 bytes,
    // starting with a zero (always)
    // and then the next nine bytes
