Introduction: Arduino CPU+RAM Usage Monitor LCD

Hi all,

I tody i made a Arduino CPU+RAM usage monitor using a simple Arduino sketch and a program.
In this instructable i will show you how to make it.
The program features an Arduino connection tester and you can write custom text to the LCD and also monitor the CPU+RAM usage on your pc.

Step 1: Stuff You Need

The stuff you will need for this project:

-Jumper wires
-LCD display i used HD44780
-potmeter  10K
-Arduino Uno/Mega
-.Net Framework 4/4.5
-Arduino Software

Step 2: Connect the LCD to the Arduino

Follow the image from the Arduino website to connect the Arduino to the LCD.
Make sure all the connections are right!

Step 3: Upload the Code to the Arduino

Connect your Arduino to your pc/laptop.
Open the Arduino sketch i attatched and upload the code
Make sure there are NO errors!

When the download didn't work here is the code:

#include <LiquidCrystal.h>

//Set's lcd to the Arduino's ports
LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

void setup() {
  lcd.begin(16, 2);


void loop() {

  String content = "";
  char character;

  while(Serial.available()) {
      character =;

  if (content != "") {

    if (content == "`") {
  content = "";

if (content == "*") {
  content = "";


    if (content == "~") {


Step 4: Run the Windows Program

Now you can run the Windows appalication that sends the CPU and RAM usage over the serial port to the Arduino.
So make sure that your Arduino's USB is connected to your PC.

New version:

For the source code:

Step 5: Final Product

You are now finished!
When your Arduino or PC is not working correctly please send me a message and i will help you out!

Have a great day!

Arduino Contest

Participated in the
Arduino Contest