                 digitalWrite(MAX7219_CS, HIGH);
                 break;
         case 88: 
-                analogReference(DEFAULT);
                 send_int(analogRead(PHOTO_RESISTOR));
                 break;
 


            // current sensor
        case 86:
            analogReference(INTERNAL);
            send_int(analogRead(CURRENT_SENSOR_PIN));
            break;


    //lcd setup
    lcdSetup();

    pinMode(RELAY_PIN, OUTPUT);
    digitalWrite(RELAY_PIN, HIGH);
    Serial.begin(9600);
