i2c_2.bas

Low End Microchip PICs C函数

' I2C_2.Bas (BX24)
'
' Compile with I2C_BX24.Bas LCDCntr.Bas and SerCom3.Bas
'
' Used to test I2C_SLV2.C (PIC16F877).
'
' Addresses I2C device with address 0x40 and commands it to perform a temperature measurement
' on Ch 0 (0x80 + channel)followed by a two second delay.  The nine bytes are then read and 
' displayed on a serial LCD.
'
' Then addreses the same device and commands it to flash an LED 8 times (0x70 + num_flashes).
'
' BX24			Serial LCD+		PIC16F877
'
' Term 13 -------------> (term 2)
'
' Term 15 <------------------------------------> RC4/SDA (term 23)
' Term 14 -------------------------------------> RC3/SCL (term 18)
'
' 4.7K pull-up resistors to +5 VDC on both SDA and SCL
'
' copyright, Peter H. Anderson, Georgetown, SC, Mar, '01

Public Const SDA_PIN as Byte = 15
Public Const SCL_PIN as Byte = 16

Sub Main()

   Dim Buff(1 to 9) as Byte
   Dim N as Integer
	
   Call DefineCom3(0, 13, &H08) ' noninverted, no parity, 8 data bits
		                  ' input, output
		  
   Call OpenSerialPort_3(9600)
   Call LCDInit()   
	
   Do
	'perform a temperature measurement
       Call I2C_start()
       Call I2C_out_byte(&H40)	' address, write 
	
       Call Sleep(0.005)
       Call I2C_out_byte(&H80)	' temperature measurement on Ch 0
       Call I2C_stop()
		
       Call Sleep(2.0)
		
       Call I2C_start()
       Call I2C_out_byte(&H41)	' address, read
			
       For N = 1 to 8	   
          Buff(N) = I2C_in_byte(TRUE)
       Next
		
       Buff(9) = I2C_in_byte(FALSE)	
       Call I2C_stop()
		
       Call DisplayResult(Buff)
		
       ' flash LED	
       Call I2C_start()
       Call I2C_out_byte(&H40)	' address write
       Call Sleep(0.005)
       Call I2C_out_byte(&H78)	' flash LED 8 times
       Call I2C_stop()
       Call Sleep(1.0)	' be sure task has time to complete				 
   Loop
End Sub

Sub DisplayResult(ByRef Vals() as Byte)
   Dim N as Integer
   Call LCDClearAll()
	
   For N = 1 to 4
      Call PutHexB_3(Vals(N))
      Call PutByte_3(Asc(" "))
   Next
	
   Call LCDSetCursorPosition(20)	' beginning of second line
	
   For N = 5 to 8
      Call PutHexB_3(Vals(N))
      Call PutByte_3(Asc(" "))
   Next

   Call LCDSetCursorPosition(40)	' beginning of third line
   Call PutHexB_3(Vals(9))
End Sub		
	   
Sub PutHexB_3(ByVal X as Byte)
   Dim Y as Byte

   Y = X\16
   Y = ToHexChar(Y)
   Call PutByte_3(Y)
   Y = X MOD 16
   Y = ToHexChar(Y)
   Call PutByte_3(Y)
End Sub

Function ToHexChar(ByVal X as Byte) as Byte
   Dim ReturnVal as Byte
   If (X < 10) Then
      ReturnVal = X + Asc("0")
   Else
      ReturnVal = X - 10 + Asc("A")
   End If
   ToHexChar = ReturnVal
End Function