Arduino gets "Stuck" while executing commands in Serial Monitor

Other Hardware Motors, Mechanics, Power and CNC
1

Hi guys, I wanted your help on my project with Liquid pumps. I was trying to follow this project "https://arduinogetstarted.com/tutorials/arduino-controls-pump" while I added SerialEvents to be able to control the pump through the Serial Monitor. Unfortunately I kept on encountering a problem where the Serial would either completely freeze and be unresponsive or it would reset itself and go back to void setup. Please note that I am using the Raspberry Pi3 to run the Arduino IDE which is then connected to the Arduino Uno through a USB cable.

const int RELAY_PIN1 = 7;

//int inputValue = 0; for Communicating with the RPI
int pumpcount = 0;

String inputString = "";
boolean stringComplete = false;

void setup()
{
  pinMode(RELAY_PIN1, OUTPUT);
  digitalWrite(RELAY_PIN1, LOW);
  Serial.begin (9600);
  /*
  while (Serial.available()<=0) 
 {
   Serial.println("Waiting For Command:");
   delay(500);
 }
 */
}

void loop()
{
  if (stringComplete)
  {
    if(inputString.startsWith("pump"))
    {
      pumpOn(2000);
    }
    else
    {
      Serial.println("Invalid Command");
    }
  //Reset String
  stringComplete = false;
  inputString = "";
  }
  delay(10);
}

void serialEvent()
{
  while (Serial.available()) 
  {
    char inChar = (char)Serial.read();
    inputString += inChar;
    if (inChar == '\n') 
    {
      stringComplete = true;
    }
  }
}

void pumpOn(int secs)
{
  Serial.println(pumpcount);
  pumpcount +=1;
  digitalWrite(RELAY_PIN1, HIGH);
  Serial.print(" :Pump is ON");
  delay(secs);
  digitalWrite(RELAY_PIN1, LOW);
  Serial.println("Pump is OFF");
  delay(secs);
}

-----Sample Serial Monitor Output------
0
:Pump is ONPump is OFF
1
:Pump is ONPump is OFF
2
:Pump is ONPump is OFF
3
:Pump is ONPump is OFF
4
:¨0
:Pump is ONPump0
:Pump is ONPump is OFF
1
:Pump is ONPump is OFF
2
:Pump is ¯ú0
:Pump is ONPumÿ0
:Pump is ONPump is OFF
1
:Pump is ONPump is OFF
2
:Pump is O
-----Sample Serial Monitor Output------

Was hoping you guys could help me figure out the problem.

Sample Fritzing
Sample Fritzing1240×895 225 KB

2

Post ya code.

3

Sorry just figured out how to do that.

4

Switching the relay seems to be causing a power glitch and resetting your Arduino. Usually, that is caused by an inadequate power source.

5

Or forgetting to use a diode across the pump.
And/or pump wiring too close to Arduino wiring.
Leo..