//demonstration of button reads on the TM1638 LED & KEY board
const int strobePin = 8;
const int clockPin = 9;
const int dataPin = 10;
int keys1;
int keys2;
int keys3;
int keys4;


void setup()
{
  Serial.begin(9600);
  pinMode(strobePin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(dataPin, OUTPUT);
  digitalWrite(strobePin, LOW); //set the strobe low so it'll accept instruction
  shiftOut(dataPin, clockPin, LSBFIRST, 0x8F);  // activate and set brightness to max
  digitalWrite(strobePin, HIGH);
  
  
}

void loop()
{
  digitalWrite(strobePin, LOW); //set the strobe low so it'll accept instruction
  shiftOut(dataPin, clockPin, LSBFIRST, 0x42);  // activate and set brightness to max
  pinMode(dataPin, INPUT_PULLUP); //Instruction received, board changes DIO to OUTPUT, we now need to set the pin as INPUT
  keys1 = shiftIn(dataPin, clockPin, LSBFIRST); // read in first byte of data
  keys2 = shiftIn(dataPin, clockPin, LSBFIRST); // read in first byte of data
  keys3 = shiftIn(dataPin, clockPin, LSBFIRST); // read in first byte of data
  keys4 = shiftIn(dataPin, clockPin, LSBFIRST); // read in first byte of data
  Serial.print("  Byte 0:");
  Serial.print(keys1);
  Serial.print("  Byte 1:");
  Serial.print(keys2);
  Serial.print("  Byte 2:");
  Serial.print(keys3);
  Serial.print("  Byte 3:");
  Serial.println(keys4);
  digitalWrite(strobePin, HIGH); // all data is received, and just like any other instruction, the strobe line must go high when finished
  pinMode(dataPin, OUTPUT); //having sent all data, the board now sets the DIO line as INPUT, we switch the arduino back to OUTPUT
  delay(10);  // just give the serial monitor a brief delay so we can read stuff

}