I'm new to C# programming and trying to write an application which is part of my final thesis.
I have a microprocessor that continuously send data from a sensor to my computer via serial port. All I want is to plotting this data using Zedgraph.
The problem is that the graph got too much delay and time lag. It seems the problem happens because I continuously update the whole graph at a very high rate. I have stucked on this problem in a week and still dont find out a solution. I'll be more than happy if someone can help me out.
This is my code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using ZedGraph;
using System.IO.Ports;
using System.Threading;
namespace DynamicData
{
public partial class Form1 : Form
{
private SerialPort port;
private string buffer = "";
private void connect()
{
port = new SerialPort("COM8", 115200, Parity.None, 8, StopBits.One);
port.DataReceived += new System.IO.Ports.SerialDataReceivedEventHandler(port_DataReceived);
if (!port.IsOpen) port.Open();
}
public Form1()
{
InitializeComponent();
}
private void Form1_Load( object sender, EventArgs e )
{
connect();
GraphPane myPane = zedGraphControl1.GraphPane;
RollingPointPairList list = new RollingPointPairList(500);
LineItem curve = myPane.AddCurve( "Sensor", list, Color.Blue, SymbolType.None );
myPane.XAxis.Scale.Min = 0;
myPane.XAxis.Scale.Max = 10;
myPane.YAxis.Scale.Min = 0;
myPane.YAxis.Scale.Max = 300;
myPane.XAxis.Scale.MinorStep = 0.5;
myPane.XAxis.Scale.MajorStep = 1;
zedGraphControl1.AxisChange();
}
private void port_DataReceived(object sender, System.IO.Ports.SerialDataReceivedEventArgs e)
{
//sample data: ;100*100000:
//sampling rate ~100Hz
buffer += port.ReadExisting();
//flush incomplete package
while (buffer[0] != ';')
{
buffer = buffer.Remove(0, 1);
if (buffer.Length < 1) break;
}
//got a complete package, go to data handling
while (buffer.Contains(":"))
{
DataHandling();
}
}
private void DataHandling()
{
string[] nameArray = buffer.Split(new[] { ";", ":", "*" }, StringSplitOptions.RemoveEmptyEntries);
//plot sensor data vs. time
draw(Convert.ToInt32(nameArray[0]), Convert.ToInt32(nameArray[1]));
//remove handled package in buffer
var index = buffer.IndexOf(":");
buffer = buffer.Remove(0, index + 1);
}
double time = 0;
private void draw(int sensor, int t)
{
//convert tick to sec (uP clock rate = 16MHZ)
time = time + (t / 16000000.0);
// Get the first CurveItem in the graph
LineItem curve = zedGraphControl1.GraphPane.CurveList[0] as LineItem;
// Get the PointPairList
IPointListEdit list = curve.Points as IPointListEdit;
list.Add(time, sensor);
//Keep the X scale at a rolling 10 second interval, with one
//major step between the max X value and the end of the axis
Scale xScale = zedGraphControl1.GraphPane.XAxis.Scale;
if (time > xScale.Max - xScale.MajorStep)
{
xScale.Max = time + xScale.MajorStep;
xScale.Min = xScale.Max - 10.0;
}
//Display sensor data
this.Invoke(new Action(() => { textBox1.Text = byte1.ToString(); }));
axisChangeZedGraph(zedGraphControl1);
}
delegate void axisChangeZedGraphCallBack(ZedGraphControl zg);
private void axisChangeZedGraph(ZedGraphControl zg)
{
if (zg.InvokeRequired)
{
axisChangeZedGraphCallBack ad = new axisChangeZedGraphCallBack(axisChangeZedGraph);
zg.Invoke(ad, new object[] { zg });
}
else
{
// zg.AxisChange();
zg.Invalidate();
zg.Refresh();
}
}
}
}