Arduino - serial communication Visual Studio

Sunday, December 18, 2016

This article will show how to make serial communication between Arduino and Visual Studio C++ through COM (UART) port
(1) Arduino will sent data to Visual Studio program:
(2) Visual Studio program will send data to Arduino. Arduino received it, then feed it back to Visual Studio program

Overview steps:
1. Hardware connection
2. Arduino program
3. Visual Studio program

1. Hardware connection

2. Arduino program
Make a program for Arduino. At start up, Arduino will send a string (a sentence) in every 0.5sec. This will stop until User send data (string) to Arduino, then Arduino will send it back to User. In this case, User is Visual Studio program (in part 3)

The code can be download at here - Google share
String mySt;
char myChar = 0;
int i=0;

void setup() {
  // start serial port at 9600 bps:
  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only

  establishContact();  // send a byte to establish contact until receiver responds

void loop() {
  if (Serial.available() > 0) {
    myChar =;
    mySt +=myChar;  //receive string from Computer
  if ((mySt.length() >0)&(!Serial.available())) {
    Serial.print(mySt); //Print received string to Computer
void establishContact() {
  while (Serial.available() <= 0) {
    Serial.print("Arduino send: ");
    Serial.println(i);  //Print increasing value to Computer

3. Visual Studio porgram
Make a window application -> save it

Add button, textbox, label to the Form( taken from Toolbox in the left):

Click on button, textbox, label to see Properties on Toolbox in the right. Remember the name of each item for program in latter section.

Add component "serial Port" and "timer"

Also see properties to know the name each item. Remember to rename "serialPort1" -> "Portname" to COM-Port of Arduino (this case is COM4)

Programming works:
The whole code of Visual Studio program can be downloaded at here - Google share
(1) Double click to Form1 -> input following code.
Meaning: open (Arduino) COM-Port
               start timer1
private: System::Void Form1_Load(System::Object^  sender, System::EventArgs^  e) {

(2) Double click to Button1 -> input following code
Meaning: send string from textBox1 to (Arduino) COM-Port
private: System::Void button1_Click(System::Object^  sender, System::EventArgs^  e) {

(3) Double click to timer1 -> input following code
Meaning: every time timer1 is tick (it will tick every 0.1s -> setting in "Interval" of Properties of timer1), label1 will update information.
private: System::Void timer1_Tick(System::Object^  sender, System::EventArgs^  e) {

(4) Click to serialPort1 -> see at Properties toolbox -> click at "Event" icon -> double click at "DataReceived"
Then, input following code.
Meaning: read COM-Port data at every time receiving -> save it to "mStr"
private: System::Void serialPort1_DataReceived(System::Object^  sender, System::IO::Ports::SerialDataReceivedEventArgs^  e) {

Auxiliary code:
(1) Meaning: when Form1 is close -> close COM-Port, and stop timer1
if (components)
delete components;

(2) Meaning: make global variable "mStr"
/// <summary>
/// Required designer variable.
String^ mStr;
/// </summary>

After all, click icon "Local Window Debugger" to build and run program

If every thing run smoothly, a window form will appear (note: Arduino should connected to Computer through COM4 with program as in Step2)

At result (1): Form1 will show result from Arduino
At result (2): Form1 will sent data to Arduino, then receive it after Arduino sending.


  1. yes! This is wonderful. I try'd this with a blanc universal app, but this seems to work differently.

    I was thinking if I use a universal app, I could use both my computer and my tablet to connect with arduino. Do you know how to do this

  2. Sorry. I have never try this. To communicate with tablet, you can use ESP12E which has wifi connection



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