#include <SoftwareSerial.h>
SoftwareSerial Komunikace(12,13);
unsigned char play[6] = {0x7E,0x04,0x03,0x00,0x01,0xEF};
unsigned char SC_SD[5] = {0x7E,0x03,0x09,0x01,0xEF};
unsigned char play_mode[5] = {0x7E,0x03,0x11,0x00,0xEF};
unsigned char PredchoziPisnicka[4] = {0x7E,0x02,0x02,0xEF};
unsigned char DalsiPisnicka[4] = {0x7E, 0x02, 0x01, 0xEF};
unsigned char HlasitostPlus[4] = {0x7E,0x02,0x04,0xEF};
unsigned char HlasitostMinus[4] = {0x7E,0x02,0x05,0xEF};
int adc_key_val[5] ={20,50, 100, 200, 600 };
int NUM_KEYS = 5;
int adc_key_in;
int key=-1;
int oldkey=-1;
void setup()
{
  Serial.begin(9600);
  Komunikace.begin(9600);
  Komunikace.write(SC_SD,5);
}
void loop()
{
  adc_key_in = analogRead(0);    // read the value from the sensor
  key = get_key(adc_key_in);  // convert into key press

  if (key != oldkey)   // if keypress is detected
   {
    delay(50);  // wait for debounce time
    adc_key_in = analogRead(0);    // read the value from the sensor
    key = get_key(adc_key_in);    // convert into key press
    if (key != oldkey)
    {
      oldkey = key;
      if (key >=0){
        switch(key)
        {
           case 0:Komunikace.write(play,6);
                  break;
           case 1:
                    for(int i = 0; i < 10; i++){
                    Komunikace.write(HlasitostPlus, 4);
                    }
                  break;
           case 2:
                    for(int i = 0; i < 10; i++){
                    Komunikace.write(HlasitostMinus, 4);
                    }
                  break;
           case 3:Komunikace.write(PredchoziPisnicka, 4);
                  break;
           case 4:Komunikace.write(DalsiPisnicka, 4);
                  break;
        }
      }
    }
  }
 delay(100);
}
// Convert ADC value to key number
int get_key(unsigned int input)
{
    int k;
    for (k = 0; k < NUM_KEYS; k++)
    {
      if (input < adc_key_val[k])
     {
            return k;
        }
   }
       if (k >= NUM_KEYS)k = -1;  // No valid key pressed
       return k;
}