volatile uint8_t adc_flag = 0;
volatile uint16_t adc_val;
volatile uint32_t adc_sum;
volatile uint16_t adc_avg;
volatile uint16_t adc_buffer[5];
volatile uint8_t adc_buffer_pointer;
uint16_t adc_array[160];
uint8_t adc_array_pointer;
volatile uint8_t data_valid=0;
uint16_t adc_MIN;
uint16_t adc_MAX;
uint16_t adc_TRG;	//trigger level = 2/3 of peak-peak value
char bufferX[80];
float timm=0;
unsigned long currentMillis =0;
unsigned long previousMillis=0;

HardwareSerial Serial1 (PA10_R, PA9_R);// UART na remap. pinech č. 5 a 6 na STM32G030J6 pouzdro SO8
   // kanal UART1 je na branach PA10 a PA9, ale pro pouzdro SO8 musime oznacit, ze se ma pouzit remapovani 

#define LED  PB5 // pin č. 8, PB5 SO8 STM32G030J6

void setup() {
  // put your setup code here, to run once:
  adc_buffer[0]=0;
  adc_buffer[1]=0;
  adc_buffer[2]=0;
  adc_buffer[3]=0;
  adc_buffer_pointer = 0;
  adc_array_pointer = 0;
  Serial1.begin(115200);
  pinMode(LED, OUTPUT); // PB5 pin. c.8
  for(uint8_t t=0; t<150;t++){
				  adc_array[t]=0;
	}
  analogReadResolution(12);
}

void loop(){
  // put your main code here, to run repeatedly:
  currentMillis = millis();
  if(currentMillis - previousMillis >= 5){     //each 5 ms
    previousMillis = currentMillis; // save the last time 
    adc_buffer[adc_buffer_pointer] = analogRead(PB7);  // measure the voltage
    adc_buffer_pointer++;														         //and store it in buffer
	  if(adc_buffer_pointer > 3){												       //average 4 values to cancel 50Hz noise
      adc_buffer_pointer=0;
			adc_sum =0;
			for(uint8_t t=0; t<4;t++){
				  adc_sum += adc_buffer[t];
			}
      adc_avg = (uint16_t)(adc_sum/4);  //calculate average value
		  adc_array[adc_array_pointer]=adc_avg;   //add to array to calculate trigger level
		  adc_array_pointer++;
		  if(adc_array_pointer>149){adc_array_pointer=0;};
	    adc_MAX =0;  //calculate MIN and MAX values
	    adc_MIN= 65535;
	    for(uint8_t a=0;a<150;a++){
		   if(adc_array[a]> adc_MAX){adc_MAX = adc_array[a];};
		   if(adc_array[a]< adc_MIN){adc_MIN = adc_array[a];};
	    };//for(uint8_t a=0;a<100;a++)

	    //data_valid only if there is some significant peak-peak value, not only noise
		  if((adc_MAX-adc_MIN)>100){data_valid=1;}else{data_valid=0;};
		  //calculate trigger value - 2/3 of peak-peak amplitude - there is smaller peak next to the big one
		  //but it does not have high amplitude so 2/3 is safely above its value..
		  adc_TRG = (((adc_MAX-adc_MIN)/3)*2)+adc_MIN;

		  if((adc_avg>adc_TRG)&&(data_valid)){    //blink with LED when current signal value is above trigger and the signal is valid
       digitalWrite(LED, HIGH); // LED ON (privede vysokou uroven  napeti HIGH (cca 3,3 V)
       //analogWrite(LED, 200);
		  }else{
       digitalWrite(LED, LOW); // LED OFF (vypne LED) 
       //analogWrite(LED,0);
		  };

      //send the data to PC - DataPlotter format
      timm +=0.02;
      if (timm > 9999){timm=0;};
      //sprintf((char *)bufferX,"$$P-,%5.3f;",(float)(adc_avg/19859.0));
      float tmpVal0 = timm;	//----------------------------------time
      uint16_t tmpInt10 = tmpVal0;
      float tmpFrac0 = tmpVal0 - tmpInt10;
      uint16_t tmpInt20 = trunc(tmpFrac0 * 100);
      //------------------------------------------------OPTOPULSE
      float tmpVal1 = adc_avg/1241.0;
      uint16_t tmpInt11 = tmpVal1;
      float tmpFrac1 = tmpVal1 - tmpInt11;
      uint16_t tmpInt21 = trunc(tmpFrac1 * 1000);
      //
      float tmpVal2 = adc_TRG/1241.0;
      uint16_t tmpInt12 = tmpVal2;
      float tmpFrac2 = tmpVal2 - tmpInt12;
      uint16_t tmpInt22 = trunc(tmpFrac2 * 1000);
      //----------------------------------------------------------                    /   time         /       pulse     /   TRG pulse     /
      sprintf((char *)bufferX,"$$P%04u.%02u,%01u.%03u,%01u.%03u;",tmpInt10,tmpInt20,tmpInt11,tmpInt21,tmpInt12,tmpInt22);
      //  $$P0000.22,2.255,1.188;
      Serial1.print(bufferX);
    }
  }
}