I have written a simple program which receive data from serial port i.e (temperature) and display on a line graph. but i require accumlate the graph data upto 10 minutes on screen. after that it again accumlate next 10 minutes data.
**The Code of VB.Net program is below :**
Imports System.Drawing.Image
Imports System.IO.Ports
Public Class frmGraph
Dim WithEvents port2 As SerialPort = _
New SerialPort("COM2", 19200, Parity.Even, 7, StopBits.One)
' Variables to store the changing values to be charted (previous and current)
Private OldValue As Single = 0
Private NewValue As Single = 0
Dim XMove As Integer = 4
Dim Chunks As Integer = 10
Private Sub frmGraph_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
SwitchMT500()
ReadLineAddress()
txtMin.Text = 620
txtMax.Text = 630
' Paint Guidelines on picGraph
picGraph.Image = DisplayGuidelines(picGraph, Chunks)
' Paint Guidelines and Numbers on picValues
picValues.Image = Me.DisplayVerticalValues(picValues, Chunks, CInt(txtMin.Text), CInt(txtMax.Text))
ReadTemperature()
End Sub
Private Function DisplayGuidelines(ByVal PicBox As PictureBox, ByVal chunks As Integer) As Bitmap
' Step 1
' Create a bitmap to draw on and grab its Graphics Object
Dim bm As New Bitmap(PicBox.Width, PicBox.Height)
Dim gr As Graphics = Graphics.FromImage(bm)
' Step 2
' Draw guidelines on main chart.
' Get the total height available and split it into chunks
Dim total As Integer = PicBox.Height
Dim chunk As Single = total / chunks
' Step 3
For i As Single = chunk To total Step chunk
gr.DrawLine(Pens.WhiteSmoke, 0, i, PicBox.Width, i)
Next i
' Step 4
' return the results.
Return bm
' Step 5
gr.Dispose()
End Function
Private Function DisplayVerticalValues(ByVal PB As PictureBox, ByVal HowManyChunks As Single, _
ByVal MinValue As Single, ByVal MaxValue As Single) As Bitmap
' Step 1
Dim bmp As New Bitmap(PB.Width, PB.Height)
Dim gv As Graphics = Graphics.FromImage(bmp)
' Step 2
' Draw guidelines on values strip
' Get the total height available and split it into chunks
' This value represents a number of pixels
Dim TotalPixels As Integer = PB.Height
Dim SingleChunk As Single = TotalPixels / HowManyChunks
For i As Single = SingleChunk To TotalPixels Step SingleChunk
gv.DrawLine(Pens.WhiteSmoke, 0, i, PB.Width, i)
Next i
' Step 3
' Draw Numbers as Text, correctly spaced vertically
' Begin with the highest value allowed
Dim NextMarker As Integer = MaxValue
' Calculate the plottable range
Dim ValueRange As Integer = MaxValue - MinValue
' Draw the numbers, decrementing values proportionately each time through the loop
For i As Single = 0 To TotalPixels Step SingleChunk
gv.DrawString(CStr(NextMarker), New Font("Verdana", 8, FontStyle.Regular), Brushes.Black, 1, i)
NextMarker -= (ValueRange / HowManyChunks)
Next
' Step 4
Return bmp
' Step 5
gv.Dispose()
End Function
Private Function DisplayGuidelinesAndChart(ByVal PicBox As PictureBox, ByVal chunks As Integer, _
ByVal XMove As Integer, ByVal NewValue As Single, ByVal Min As Single, ByVal Max As Single) As Bitmap
' Step 1
' Grab the current image (the latest version of the chart)
Dim bm As New Bitmap(PicBox.Width, PicBox.Height)
Dim gr As Graphics = Graphics.FromImage(bm)
' Step 2
' Get the total height available and split it into chunks
Dim total As Integer = PicBox.Height
Dim chunk As Single = total / chunks
' Tack missing guidelines to right hand side on the Graphics object.
For i As Single = chunk To total Step chunk
gr.DrawLine(Pens.WhiteSmoke, PicBox.Width - XMove, i, PicBox.Width, i)
Next i
' Step 3
' Draw this grabbed image, placing it XMove pixels to the left
If Not IsNothing(PicBox.Image) Then
gr.DrawImage(PicBox.Image, -XMove, 0)
End If
' Step 4
' Plot the new value.
' Calculate the scaling required to make full use of the height of
' the PictureBox
Dim ValueRange As Single = Max - Min
Dim vScale As Single = PicBox.Height / ValueRange
' Apply the scale to the current value
NewValue *= vScale
' Step 5
' Shift start point from top left to bottom left.
gr.TranslateTransform(0, PicBox.Height)
' Step 6
' Draw the next line segment on the Graphics object.
' If Min is > 0 then you need to shift the drawing down once again,
' this time to put the Min value on the horizontal axis
If Min > 0 Then gr.TranslateTransform(0, Min * vScale)
Dim p As Pen = New Pen(Color.Navy, 1)
gr.DrawLine(p, _
PicBox.Width - 1 - XMove, -OldValue, _
PicBox.Width - 1, -NewValue)
OldValue = NewValue
' Step 7
' Return the Bitmap .
Return bm
' Calculate length of baseline drawn by the code above
BaseLineLength = PicBox.Width
' Calculate the width of each line segment
LineWidth = (BaseLineLength / Sales.ToArray.Length)
' Step 8
' All done
gr.Dispose()
End Function
Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
picValues.Image = Me.DisplayVerticalValues(picValues, Chunks, CInt(txtMin.Text), CInt(txtMax.Text))
ReadTemperature()
End Sub
Private Function ReadTemperature()
Dim strValue as string
strValue = port2.ReadExisting
'picGraph.Image = DisplayGuidelinesAndChart(picGraph, Chunks, XMove, strvalue, CInt(txtMin.Text), CInt(txtMax.Text))
picGraph.Image = DisplayGuidelinesAndChart(picGraph, Chunks, XMove, strvalue, CInt(txtMin.Text), CInt(txtMax.Text))
lblValue.Text = strvalue
End Function
End ClassKindly provide code or functions so that i accumulate reading data from serial port on graph upto 10 minutes.