Read Data From Arduino Sensors in Visual Studio C#

Here's a quick tutorial on how to receive data from an Arduino Uno microcontroller in a Visual Studio app written in C#. Here I'm using a DHT11 temperature sensor but the same technique will work with pretty much any sensor that you can connect to an Arduino.

All you need is an Arduino Uno, a USB cable and a Windows PC. Any type of sensor is optional, but I highly recommend the DHT11 or DHT22 temperature and humidity sensors as good modules for beginner's IoT projects. No external libraries or 3rd party devices are required.

Arduino and C# source code is at the bottom of this description.

00:00 - Introduction
00:30 - Circuit Diagram
00:52 - Arduino Code
03:48 - C# Code
07:40 - Integration Testing

If you have any questions about the C# or Arduino code I present in the video then leave a comment below. I think the biggest potential problem with it is that it won't work if you accidentally leave the Arduino IDE's Serial Monitor window open. Also ensure you're using the correct serial port / COM port name and baud rate in both Visual Studio and the Arduino IDE. Finally if you have a four pin DHT11 sensor then you'll have to read the docs or search online to find out how to wire up your specific sensor. Also check the Adafruit DHT Sensor Library's DHTTester example's source code because this also contain notes on correct wiring.

Incidentally I'm using the 3.3V input pin to supply power from the Arduino but the DHT11 will also work on 5V.

As I explain in the video cheap $1 sensors shouldn't be relied on for very precise measurements of temperature or humidity. If you're building something important then buy a professional quality sensor.

Arduino code:

#include "DHT.h"
#define DHTPIN 2
#define DHTTYPE DHT11
DHT dht(DHTPIN, DHTTYPE);

void setup() {
}

void loop() {
delay(2000);

if (isnan(h) || isnan(t) || isnan(f)) {
return;
}

}

Visual Studio C# code:

using System;
using System.Windows.Forms;
using System.IO.Ports;

namespace Temperature_Recorder
{
public partial class Form1 : Form
{
SerialPort serialPort;

public Form1()
{
InitializeComponent();
timer1.Interval = 1000;
timer1.Start();
serialPort = new SerialPort("COM12", 9600);
try
{
serialPort.Open();
}
catch
{
Console.WriteLine("Unable to open COM port - check it's not in use.");
}

}

private void timer1_Tick(object sender, EventArgs e)
{
bool haveTemperature = false;
string temperature = string.Empty;

while (!haveTemperature)
{
temperature = serialPort.ReadLine();
if (!string.IsNullOrEmpty(temperature))
{
haveTemperature = true;
}
}

if (haveTemperature) {
textBox1.Text += "Temperature is:" + temperature + " °C" + Environment.NewLine;
}

}
}
}

[amirkian]

I found it to be very informative and easy to understand. Thanks man.

[brvk]

Great video. I was having issues with the program being slow. I found out that if I use ReadExisting() instead of ReadLine(), it speeds up the program.

[teobellverwhite]

hi, i found an error when running the script

looked everywhere but no answer helped me

[rosnelycruz]

Hola, me gusto tu explicación, pero ahora como enviarías esos datos a una hoja de Excel?

[GILBERTATILANO-hc]

how about temperature and HUMIDITY sir?

[livetohash]

Can we read direct? Like no arduino? Just direct to the PC? The library can be used by a PC in an app, it's all just C anyway... 🤔

[gabalew]

This is Great Video tutorial! is there anyway how to contact you? i need some help with sending data(Obstacle Sensor) from arduino to windows forms.