4 Channel miniscope

int potentiometer_pin = A0;                                     //Define the analog input pin
int potentiometer_pin1 = A1;                                     //Define the analog input pin
int potentiometer_pin2 = A2;                                     //Define the analog input pin
int potentiometer_pin3 = A3;                                     //Define the analog input pin
const int buttonPin = 8;         // the number of the pushbutton pin
// variables will change:
int buttonState = 0;         // variable for reading the pushbutton status

void setup() {
  Serial.begin(9600);                                           //Default baud rate of the Nextion TFT is 9600
  pinMode(potentiometer_pin, INPUT);                            //Define pin as input
  pinMode(potentiometer_pin1, INPUT);                            //Define pin as input
  pinMode(potentiometer_pin2, INPUT);                            //Define pin as input
  pinMode(potentiometer_pin3, INPUT);                            //Define pin as input
  pinMode(buttonPin, INPUT);
}

void loop() {
  // read the state of the pushbutton value:
  buttonState = digitalRead(buttonPin);
  if (buttonState == HIGH) {
    routine0();
    routine1();
    routine2();
    routine3();
  }

}

void routine0() {

  int  Value = map(analogRead(potentiometer_pin), 0, 1024, 0, 200); //Read the pot value ann map it to 0.255 (max value of waveform=255)
  String Tosend = "add ";                                       //We send the string "add "
  Tosend += 1;                                                  //send the id of the block you want to add the value to
  Tosend += ",";
  Tosend += 0;                                                  //Channel of taht id, in this case channel 0 of the waveform
  Tosend += ",";
  Tosend += Value;                                              //Send the value and 3 full bytes
  //Send the value and 3 full bytes
  Serial.print(Tosend);
  Serial.write(0xff);
  Serial.write(0xff);
  Serial.write(0xff);
}

void routine1() {

  int  Value1 = map(analogRead(potentiometer_pin1), 0, 1024, 0, 200); //Read the pot value ann map it to 0.255 (max value of waveform=255)
  String Tosend = "add ";                                       //We send the string "add "
  Tosend += 1;                                                  //send the id of the block you want to add the value to
  Tosend += ",";
  Tosend += 1;                                                  //Channel of taht id, in this case channel 0 of the waveform
  Tosend += ",";
  Tosend += (Value1 + 10);
  //Send the value and 3 full bytes
  Serial.print(Tosend);
  Serial.write(0xff);
  Serial.write(0xff);
  Serial.write(0xff);

}

void routine2() {

  int  Value = map(analogRead(potentiometer_pin2), 0, 1024, 0, 200); //Read the pot value ann map it to 0.255 (max value of waveform=255)
  String Tosend = "add ";                                       //We send the string "add "
  Tosend += 1;                                                  //send the id of the block you want to add the value to
  Tosend += ",";
  Tosend += 2;                                                  //Channel of taht id, in this case channel 0 of the waveform
  Tosend += ",";
  Tosend += (Value + 20);                                            //Send the value and 3 full bytes
  //Send the value and 3 full bytes
  Serial.print(Tosend);
  Serial.write(0xff);
  Serial.write(0xff);
  Serial.write(0xff);
}

void routine3() {

  int  Value1 = map(analogRead(potentiometer_pin3), 0, 1024, 0, 200); //Read the pot value ann map it to 0.255 (max value of waveform=255)
  String Tosend = "add ";                                       //We send the string "add "
  Tosend += 1;                                                  //send the id of the block you want to add the value to
  Tosend += ",";
  Tosend += 3;                                                  //Channel of taht id, in this case channel 0 of the waveform
  Tosend += ",";
  Tosend += (Value1 + 30);
  //Send the value and 3 full bytes
  Serial.print(Tosend);
  Serial.write(0xff);
  Serial.write(0xff);
  Serial.write(0xff);

}