C# 到 arduino 通信

Question

Good afternoon everyone,

I'm experimenting with serial communication between c# and arduino. To understand how the comms work with regards to sending numbers (I know, there's alot being discussed already but bear with me) I want to send the value of a trackbar to the arduino, and then translate this number in movement of a servo.

If I understand correctly, integers can't be sent directly but have to be converted into bytes first. So for this I would convert the numeric value of the trackbar into a byte array

in C# :

byte[] Numbers;
Numbers = BitConverter.GetBytes(trackBar1.Value);

Via serial communication I would send the value

port.Write(Numbers, 0, 1);

And this is where I'm going wrong I think The trackbar value goes from 0 to 255, so I guess I'd need to know the bytes that equal 0 to 255 to be able to adjust the last number (in my example '1') to get the correct number after translation in Arduino?

As for Arduino, I would 'translate' the bytes as follows:

int IncomingValue = Serial.parseInt();

And then I'd like to use the IncomingValue for my servo.

My question is what I'm doing incorrectly.

thanks

Answer 1

For those interested in tinkering with c# to arduino serial communication (just desribing the issue I had) and sending a value of a trackbar to use in arduino:

make yourself a form project and name it whatever you like. Then create a trackbar. I will create a trackbar with a minimum value of 0 and a maximum of 255 as follows:

trackbar1.Minimum = 0;
trackbar1.Maximum = 255;
trackBar1.TickFrequency = 10;   // this will set ticks every 10 units.

Now we can setup the actual communication between c# and arduino. I'll start with c#.

Opening a port:

  port = new SerialPort("COM5", 9600);   //Set your Arduino COM port and baud rate
            port.Open();

Now we also need to create an event to close the port when the program shuts:

 void Form1_FormClosed(object sender, FormClosedEventArgs e)
        {
            if (port != null && port.IsOpen)
            {
                port.Close();
            }
        }

Now we have set up the port, but we still need data to send. In our example we told we were going to send the value of the trackbar. To do this, click on your trackbar and find the trackBar1_Scroll event and double click it. This basically creates the event of scrolling the trackbar and now we have to describe in this event what we want to happen.

We want to send the data of the trackbar via serial. The trackbar value is retrieved as follows:

trackbar1.value

Now we know how to retrieve the value, we have to look at the options of sending it, there's 3 options using port.write() , we'll use this later:

-Write(String)
-Write(Byte[], Int32, Int32)
-Write(Char[], Int32, Int32)

but as I'm working with an int, I found that the second one was the one I needed. As you can see we need a Byte array to be able to send this, so we will cast our trackbar data into a byte array by using BitConverter and declaring a byte array called Numbers:

byte[] Numbers = BitConverter.GetBytes(trackBar1.Value);

Now we have every element we need:

• The port which has been opened. We also described when to close it.
• The trackbar and its data to send.
• The data of the trackbar 'packaged' the correct way to be able to send it.

the only thing we didn't do is describe the scroll event, but now we have the correct data format, we can:

private void trackBar1_Scroll(object sender, EventArgs e)
        {
            
            byte[] Numbers = BitConverter.GetBytes(trackBar1.Value);

            port.Write(Numbers, 0, 1);

        }

so in c# our code will look like this:

 public Form1()
        {
            InitializeComponent();
            
            trackBar1.Minimum = 0;
            trackBar1.Maximum = 255;
            trackBar1.TickFrequency = 10;

            port = new SerialPort("COM5", 9600);//Set your board COM
            port.Open();

            this.FormClosed += new FormClosedEventHandler(Form1_FormClosed);
           
        }
 
void Form1_FormClosed(object sender, FormClosedEventArgs e)
        {
            if (port != null && port.IsOpen)
            {
                port.Close();
            }
        }

private void trackBar1_Scroll(object sender, EventArgs e)
        {
            byte[] Numbers = BitConverter.GetBytes(trackBar1.Value);

            port.Write(Numbers, 0, 1);

        }

As for arduino, all we need to do is:

A] Start our serial

B] Read the incoming data

#include <LiquidCrystal.h>                 // include the LCD library

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);     //define the LCD display

int Number;                               //define the number int (the one we'll store our received trackbar value in)
    
    void setup()
    {
      Serial.begin(9600);           //A] Start our serial
    }
    
    void loop()
    {
      
       lcd.setCursor(0, 0);     // Set the LCD cursor at the top left corner

      if (Serial.available() > 0 ) {         //B] Read the incoming data
        nummer = Serial.read();              //
        lcd.print(nummer);                   //
      }                                      //
      else {};                               //
                      
   }

I used an LCD to read the data as I couldn't figure out a way to open the serial monitor with the serial communication between c# and arduino happening. that's why I included an LCD.

I feel explaining this is beyond the scope of this little issue I had.

I hope this helps other beginners like me in the future.

thanks to those who were helpful!