C# - Read serial data from MSP430 and display to chart

Question

I tried and read a lot but now I am at the point where I stand still. I have a MSP430 witch sends it´s temperature data to my notebook over serial. Data get´s fine to my application and is written to my console.

Screenshot: Temperature Data from MSP430 in Console

Only every 3 numbers are interisting. Forget to set it to "WriteLine"

So my next step is to read the data to a form and display them in a chart. This is the point where I didn`t find my error. The chart gets the first value correct and then returns to zeros. I think that this is an error in my thread function but I am totally new to threading so I can not find the error.

Hope you can help me fixing it!

Next I will show you the code running on my MSP430 written in "Energia"

int temp;

void setup()
{
  // put your setup code here, to run once:
  Serial.begin(9600);
  Serial.println("Internal Temperature Sensor\n");
}

void loop()
{
  // put your main code here, to run repeatedly:
  temp = analogRead(TEMPSENSOR);
  Serial.print(temp);
  delay(5000);
}

And next my C# code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Windows.Forms.DataVisualization.Charting;

using System.IO.Ports;
using System.Threading;

namespace SerialReadGUI
{
  public delegate void emptyFunction();
  public partial class Form1 : Form

  {
    public Form1()
    {
        InitializeComponent();
        double[] pointsArray = { };

        chart1.ChartAreas.Add("areas");
        chart1.ChartAreas["areas"].AxisX.Minimum = 0;
        chart1.ChartAreas["areas"].AxisX.Interval = 1;
        chart1.ChartAreas["areas"].AxisY.Minimum = 20;
        chart1.ChartAreas["areas"].AxisY.Interval = 0.1;
        chart1.ChartAreas["areas"].AxisY.Maximum = 40;
        chart1.ChartAreas["areas"].AxisX.Title = "Time [s]";
        chart1.ChartAreas["areas"].AxisY.Title = "Temperature [°C]";

        chart1.Series.Add("Temperature");
        chart1.Series["Temperature"].Color = Color.Red;
        chart1.Series["Temperature"].ChartType = System.Windows.Forms.DataVisualization.Charting.SeriesChartType.Line;

        chart1.Titles.Add("Internal Temeperatur Sensor");

    }

    private void Form1_Load(object sender, EventArgs e)
    {
        SerialPort mySerialPort = new SerialPort("COM4");

        mySerialPort.BaudRate = 9600;
        mySerialPort.Parity = Parity.None;
        mySerialPort.StopBits = StopBits.One;
        mySerialPort.DataBits = 8;
        mySerialPort.Handshake = Handshake.None;

        mySerialPort.DataReceived += new SerialDataReceivedEventHandler(DataReceiveHandler);

        mySerialPort.Open();



    }

    private void DataReceiveHandler(object sender, SerialDataReceivedEventArgs e)
    {
        SerialPort sp = (SerialPort)sender;

        string indata = sp.ReadExisting();
        double temp = Double.Parse(indata);
        temp = temp / 10;
        string time = DateTime.Now.ToShortTimeString();                     

        Thread thread = new Thread(() => ChartAdd(time, temp));
        thread.IsBackground = true;
        thread.Start();
    }

    private void ChartAdd(string x, double y)
    {
        chart1.Invoke(new emptyFunction(delegate ()
        {
            chart1.Series["Temperature"].Points.AddXY(x, y);
        }));
    }
  }
}

Result of all this code is this, but like you see in the first picture, it is getting right values in the console.

Screenshot: Temperature Data from MSP430 in Chart

Looking forward to your ideas =)

Answer 1

Fixed it:

In Energia I had to change this:

Serial.print(temp);

To:

Serial.println(temp);

And in my C# code I changed this:

string indata = sp.ReadExisting();

To:

string indata = sp.ReadTo("\r");

Now I get the right values in my chart!