Hi guys,
I have to write a VI communicating via RS232 with a microcontroller for a PWM application. A colleague has given me the GUI he has developpd in VB and I would like to integrate it into my LabVIEW programme by converting the VB code into Labview code. Here's the code:
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Private Sub LoadButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles loadButton.Click
Dim bufLen As Integer = 12 // Buffer length
Dim freq As Integer = 0 // frequency
Dim pWidth As Integer = 0 // pulse width
Dim dac As Integer = 0 // Value used in oscillator setting for generating pulse frequency Dim addr As Integer = 0 // Address of the pulse width in the pulse generator. Dim rTime As Integer = 0 // duration of machining/pulse train in ms. Dim returnValue As Byte = 0 // A variable for storing the value returned by the
//microcontroller after it receives some data
Dim buffer(bufLen) As Byte // creates an array of bytes with 12 cells => buffer size = 8 x12 = 96 bits
// can you explain a bit please I know you're converting the entered values into byte and put them one by one in a specific order. This order is how the
//microcontroller expects them
addr = (Floor((pWidth - Tinh) / Tinc)) // Formula from hardware, calculates address setting for pulse generator to set pulse width. buffer(0) = Convert.ToByte(Floor(3.322 * (Log10(freq / 1039)))) // Caluclates OCT value for use in setting oscillator for pulse freq. dac = (Round(2048 - ((2078 * (2 ^ (10 + buffer(0)))) / freq))) // Calculates DAC value for use in setting oscillator for pulse freq.
buffer(1) = Convert.ToByte((dac And &HF00) >> 😎 //
// &H is the vb.net to tell it its hex code, F00 gives the top 4 bits from a 12 bit value. buffer(2) = Convert.ToByte(dac And &HFF) // For values that are larger than 256 (8bits) the value needs to be split across 2 bytes (16 bits) this gets the //bottom 8 bits. &H is the vb.net to tell it its Hex. buffer(3) = Convert.ToByte((addr And &HFF0000) >> 16) // This value may be so large it requires 3 bytes (24bits). This gets the top 8 bits. buffer(4) = Convert.ToByte((addr And &HFF00) >> 😎 // This gets the middle 8 bits. buffer(5) = Convert.ToByte(addr And &HFF)// This gets the bottom 8 bits. buffer(6) = Convert.ToByte((rTime And &HFF0000) >> 16) //This value may also be 3 bytes long.
buffer(7) = Convert.ToByte((rTime And &HFF00) >> 😎
buffer(8) = Convert.ToByte(rTime And &HFF)
buffer(9) = Convert.ToByte(2.56 * ocpBox.Value) // The ocp pulse period is formed of 256 steps or counts, so if a percentage is requested, this formula gives the number of steps/counts required to set the pulse width
buffer(10) = Convert.ToByte(tempBox.Value)
If (tempCheck.Checked = True) Then
buffer(11) = 1
Else
buffer(11) = 0
End If
freq = ((2 ^ buffer(0)) * (2078 / (2 - (dac / 1024))))
pWidth = Tinh + ((((Convert.ToInt32(buffer(3))) << 16) Or ((Convert.ToInt32(buffer(4))) << 😎 Or (Convert.ToInt32(buffer(5)))) * Tinc)
' Connect to device
serialPort1.Write(1) // Sends the number 1. This tells the microcontroller we are about to start sending data. It should respond with a zero if it is ready
//and the connection is good.
The line "serialPort1.Write(buffer, 0, bufLen)" sends the buffered data where the variables are: buffer = the buffered data; 0 = the position in the buffer to start from; bufLen = the position in the buffer to stop sending data.
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What's the best way to deal with the Convert.ToBytes and the logical masks And ??
Thanks in advance for your time and consideration,
regards
Alex
