 int plant1_value = 0;
 int plant2_value = 0;
 int plant3_value = 0;
-int voltage_value = 0;
+long voltage_value = 0;
 int temperature_value = 0;
 int light_value = 0;
 

        } else if (incomingByte == 51) { // turn relay on if input was ASCII "3"
            digitalWrite(relay_pin,HIGH);
            Serial.println("{ \"relay_state\": 1 }");
            relay_delay = 30 *4; //30s
            relay_delay_counting = true;
        } else { // otherwise, reply with sensor data
            

        delay(100);
        digitalWrite(led_pin,LOW);
    } else {
        if(relay_delay_counting){
            if(relay_delay > 0){
                relay_delay--;
