C# Windows Form - Serial Port problem / BackgroundWorker

Question

I developed a Windows Form application, using C#, that receives data through the serial port sent by a microcontroller. I'm receiving the data using the serialPort_DataReceived event in which I use ReadLine() to read the serial port. Then I use the Invoke method to call a function that will print the received string into a textBox. The problem is that the app can't keep up with the rate at which it receives the strings, for example, the string that I send from the microcontroller has the time at which it was sent and even though it has already passed 2 or 3 seconds the app is still printing the strings that were sent at the 0.2 second. And when I send a string to the microcontroller to stop sending data, the app onlys stops ptinting the data after a while, this is, it keeps printing the values stored in the receiving buffer.

I believe that is happens given the large amount of data that the app receives and the rate (I'm using a baud rate of 115200), one string for every millisecond. This is, I think that the app is always being interrupted by the DataReceived event and it doesn't has time to print the data and starts falling behind.

One way I though of overcome this problem was with multi-threading but I can't figure it out how. I already tried a few examples using the BackgroundWorker but I didn't manage to make it work at all. I'm still a noob in terms of programming Windows Form apps and even C#.

Can anyone confirm the cause of the problem? And how do I make a thread to print the received data?

score 0 · Accepted Answer · answered Dec 29 '18 at 19:23

0

You can utilize SerialPort.ReceivedBytesThreshold property and SerialPort.ReadExisting() method (or a StringBuilder instance) to update UI with a batch of strings at once rather than a single string.

For more information check:

Serial port DataReceived firing too much discussions on StackOverflow
Top 5 SerialPort Tips article by Kim Hamilton
Serial Port ReadLine vs ReadExisting or how to read the data from serial port properly discussion on StackOverflow
Quickest way to Update Multiline Textbox with Large Amount of Text discussion on StackOverflow

answered Dec 29 '18 at 19:23

Leonid Vasilev

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Thanks for answering, changing from ReadLine() to ReadExisting() solved the problem. But now I have another problem that is how do I split the string, to plot in a chart, given that now instead of having one string I have multiple strings stored in just one. The string has following format: "value time \n" where value goes from 0 to 1024 and time is in seconds and has 4 decimal places. Before I just had one string at each time so I used .Split(' ') but now given that the string changed I can't make it work, I already tried to do in a loop but with no success. Any suggestion? – msantos Dec 29 '18 at 21:39
String parsing problem seems unrelated to the initial question. If the answer solved your initial problem please consider accepting it and asking a new question to keep discussions of unrelated questions separate. – Leonid Vasilev Dec 30 '18 at 10:31

C# Windows Form - Serial Port problem / BackgroundWorker

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