课程设计求助~~~~~~~单片机高手进

只看该作者 · 2012-7-3 17:29

这个是题目要求：串行通信：（1）单片机不断读取p0口所接8个独立按键状态，并通过串行口送至
上位计算机，计算机上运行自编的软件将p0口8个状态用只是灯方式显示，
（2）上位机软件界面设有8个开关点击不同按键，按键开关状态用串行口发至单片机
单片机根据收到信息将8个开关状态通过p2口所接8个LED显示出来
这个是VB程序。
Private Sub Command1_Click()
Dim num As Integer
Dim b(0) As Byte
num = 0
b(0) = CByte(num)
MSComm1.OutBufferCount = 0
MSComm1.Output = b
End Sub
Private Sub Command2_Click()
Dim num As Integer
Dim b(0) As Byte
num = 1
b(0) = CByte(num)
MSComm1.OutBufferCount = 0
MSComm1.Output = b
End Sub
Private Sub Command3_Click()
Dim num As Integer
Dim b(0) As Byte
num = 2
b(0) = CByte(num)
MSComm1.OutBufferCount = 0
MSComm1.Output = b
End Sub
Private Sub Command4_Click()
Dim num As Integer
Dim b(0) As Byte
num = 3
b(0) = CByte(num)
MSComm1.OutBufferCount = 0
MSComm1.Output = b
End Sub
Private Sub Command5_Click()
Dim num As Integer
Dim b(0) As Byte
num = 4
b(0) = CByte(num)
MSComm1.OutBufferCount = 0
MSComm1.Output = b
End Sub
Private Sub Command6_Click()
Dim num As Integer
Dim b(0) As Byte
num = 5
b(0) = CByte(num)
MSComm1.OutBufferCount = 0
MSComm1.Output = b
End Sub
Private Sub Command7_Click()
Dim num As Integer
Dim b(0) As Byte
num = 6
b(0) = CByte(num)
MSComm1.OutBufferCount = 0
MSComm1.Output = b
End Sub
Private Sub Command8_Click()
Dim num As Integer
Dim b(0) As Byte
num = 7
b(0) = CByte(num)
MSComm1.OutBufferCount = 0
MSComm1.Output = b
End Sub
Private Sub Form_Load()
MSComm1.CommPort = 1
MSComm1.InputMode = comInputModeBinary
MSComm1.RThreshold = 1
MSComm1.Settings = "9600,N,8,1"
MSComm1.PortOpen = True
End Sub

Private Sub Timer1_Timer()
Dim i As Integer
Dim j As Integer
Dim Buffer As String
Dim Rsend() As Byte
Select Case MSComm1.CommEvent
Case 2
MSComm1.InputLen = 0
Buffer = MSComm1.Input
Rsend() = Buffer
For j = 0 To UBound(Rsend)
If Len(Hex(Rsend(j))) = 1 Then
Data = Data & "0" & Hex(Rsend(j))
Else
Data = Data & Hex(Rsend(j))
End If
Next
Dim s As String
Dim a As Integer
s = Data
a = Val("&H" & s)
i = CInt(a)
Data = ""
MSComm1.InBufferCount = 0
If i = 0 Then
Shape1.FillColor = vbBlack
Shape2.FillColor = vbBlack
Shape3.FillColor = vbBlack
Shape4.FillColor = vbBlack
Shape5.FillColor = vbBlack
Shape6.FillColor = vbBlack
Shape7.FillColor = vbBlack
Shape8.FillColor = vbBlack
ElseIf i = 1 Then
Shape1.FillColor = vbYellow
Shape2.FillColor = vbBlack
Shape3.FillColor = vbBlack
Shape4.FillColor = vbBlack
Shape5.FillColor = vbBlack
Shape6.FillColor = vbBlack
Shape7.FillColor = vbBlack
Shape8.FillColor = vbBlack
ElseIf i = 2 Then
Shape1.FillColor = vbBlack
Shape2.FillColor = vbYellow
Shape3.FillColor = vbBlack
Shape4.FillColor = vbBlack
Shape5.FillColor = vbBlack
Shape6.FillColor = vbBlack
Shape7.FillColor = vbBlack
Shape8.FillColor = vbBlack
ElseIf i = 3 Then
Shape1.FillColor = vbBlack
Shape2.FillColor = vbBlack
Shape3.FillColor = vbYellow
Shape4.FillColor = vbBlack
Shape5.FillColor = vbBlack
Shape6.FillColor = vbBlack
Shape7.FillColor = vbBlack
Shape8.FillColor = vbBlack
ElseIf i = 4 Then
Shape1.FillColor = vbBlack
Shape2.FillColor = vbBlack
Shape3.FillColor = vbBlack
Shape4.FillColor = vbYellow
Shape6.FillColor = vbBlack
Shape7.FillColor = vbBlack
Shape8.FillColor = vbBlack
ElseIf i = 5 Then
Shape1.FillColor = vbBlack
Shape2.FillColor = vbBlack
Shape3.FillColor = vbBlack
Shape4.FillColor = vbBlack
Shape5.FillColor = vbYellow
Shape6.FillColor = vbBlack
Shape7.FillColor = vbBlack
Shape8.FillColor = vbBlack
ElseIf i = 6 Then
Shape1.FillColor = vbBlack
Shape2.FillColor = vbBlack
Shape3.FillColor = vbBlack
Shape4.FillColor = vbBlack
Shape5.FillColor = vbBlack
Shape6.FillColor = vbYellow
Shape7.FillColor = vbBlack
Shape8.FillColor = vbBlack
ElseIf i = 7 Then
Shape1.FillColor = vbBlack
Shape2.FillColor = vbBlack
Shape3.FillColor = vbBlack
Shape4.FillColor = vbBlack
Shape5.FillColor = vbBlack
Shape6.FillColor = vbBlack
Shape7.FillColor = vbYellow
Shape8.FillColor = vbBlack
ElseIf i = 8 Then
Shape1.FillColor = vbBlack
Shape2.FillColor = vbBlack
Shape3.FillColor = vbBlack
Shape4.FillColor = vbBlack
Shape5.FillColor = vbBlack
Shape6.FillColor = vbBlack
Shape7.FillColor = vbBlack
Shape8.FillColor = vbYellow
End If
End Select
End Sub
下面是串行通信的程序：
ORG 23H
LJMP COMPRO
ORG  40H
MAIN: MOV TMOD,#20H
MOV TL1,#0FDH
MOV TH1,#0FDH
MOV PCON,#00H
MOV SCON,#0D0H
      CLR RI
      CLR TI
SETB TR1
SETB EA
SETB ES
M1:    MOV A,P0
      MOV R0,#00H
JNB ACC.0 , M2
MOV R0,#01H
SJMP M9
M2:    JNB ACC.1  ,M3
MOV R0,#02H
SJMP M9
M3:    JNB ACC.2,M4
MOV  R0,#03H
SJMP M9
M4:    JNB  ACC.3,M5
MOV R0,#04H
SJMP  M9
M5:    JNB  ACC.4,M6
MOV R0,#05H
SJMP M9
M6:    JNB ACC.5,M7
MOV R0,#05H
SJMP  M9
M7:    JNB ACC.6,M8
MOV R0,#07H
SJMP M9
M8:    JNB ACC.7,M9
MOV R0,#08H
M9:    MOV A,R0
MOV SBUF,A
SJMP M1
COMPRO: JNB TI,RECV
CLR TI
   SJMP RETURN
RECV: CLR RI
MOV A,SBUF
      MOV DPTR ,#TAB
MOVC A,@A+DPTR
MOV P2,A
SJMP RETURN
TAB: DB 01H ,02H,04H,08H,10H,20H,40H,80H
RETURN: NOP
      RETI
END
一共有两个问题：
1.为什么P2.0初始会亮
2.为什么说通信的时候有溢出