SRF 08 Sonar Demo

Tento program meria vzdialenosť senzorom SRF08 a vypisuje hodnoty na sériový LCD displej a zároveň posiela cez USB/RS-232 do PC, kde sa dá zobraziť v terminálovom okne.

Pripojenie

SRF08: 
     SCL      CON  9         ' I2C clock
     SDA      CON  8         ' I2C data
LCD Backpack:
     LCD      CON  0         ' LCD Serial Backapck Data Line

'{$STAMP BS2}

SCL CON 9 ' I2C clock SDA CON 8 ' I2C data LCD CON 0 ' LCD Serial Backapck Data Line SDAin VAR IN8 SDAout VAR OUT8 ' To change the pins used, alter these 5 lines SDAdir VAR DIR8 ' The 4 SDA numbers must be the same, of course

loop VAR Byte ' just a looping counter I2cBuf VAR Byte ' I2c read/write buffer I2cAddr VAR Byte ' Address of I2C device I2cReg VAR Byte ' Register number within I2C device I2cData VAR Word ' Data to read/write I2cAck VAR Bit ' Acknowledge bit

                       ' LCD: Defining some useful constants for the Backpack.

N9600 CON $4054 ' Baudmode-9600 bps inverted.

   I    CON  254       ' Instruction prefix value.
 CLR    CON  1         ' LCD clear-screen instruction.

LINE2 CON 192 ' Address of 1st char of 2nd line. L1_C7 CON 135 ' Address of line 1, character 7. L2_C7 CON 199 ' Address of line 1, character 7.

 SEROUT 0,N9600,[I,CLR] ' Clear the LCD screen.
 SEROUT 0,N9600,["Range:"] ' Print the label.

Main:

 I2cAddr = $e0
 I2cData = 81          ' Rangeing command - 80 for inches, 81 for cm, 82 for uS

 I2cReg  = 0
 GOSUB  I2cByteWrite
 PAUSE  70             ' Wait for ranging to complete

 I2cReg = 1            ' Address of light sensor register
 GOSUB  I2cByteRead
 DEBUG  2,0,0, "Light Sensor    ", DEC3 I2cData, " u"

 I2cReg = 2        ' address of first ranging result
 GOSUB  I2cWordRead
 DEBUG  2,0,1, "Range           ", DEC4  I2cData, " cm"
 SEROUT 0,N9600,[I,L1_C7]                                   ' Move to line 1, character 7.
 SEROUT 0,N9600,[DEC4 I2cData, " cm"]                       ' Print message.

' --------------------------------------------------------------------------------------------

 I2cData = 82          ' Rangeing command - 80 for inches, 81 for cm, 82 for uS

 I2cReg  = 0
 GOSUB  I2cByteWrite
 PAUSE  70             ' Wait for ranging to complete

 I2cReg = 2            ' address of first ranging result
 GOSUB  I2cWordRead
 DEBUG  2,0,2, "Range           ", DEC4  I2cData, " us"
 SEROUT 0,N9600,[I,L2_C7]                                   ' Move to line 1, character 7.
 SEROUT 0,N9600,[DEC4 I2cData, " us"]                       ' Print message.

 GOTO  main

'-------------------------------------------------------------------------------------------- ' I2C subroutines follow '--------------------------------------------------------------------------------------------

I2cByteWrite: ' writes I2cData.lowbyte to I2cReg at I2cAddr

 GOSUB  I2cStart
 I2cBuf = I2cAddr
 GOSUB  I2cOutByte      ' send device address
 I2cBuf = I2cReg
 GOSUB  I2cOutByte      ' send register number
 I2cBuf = I2cData.LOWBYTE
 GOSUB  I2cOutByte      ' send the data
 GOSUB  I2cStop
 RETURN

I2cWordWrite: ' writes I2cData to I2cReg at I2cAddr

 GOSUB  I2cStart
 I2cBuf = I2cAddr
 GOSUB  I2cOutByte      ' send device address
 I2cBuf = I2cReg
 GOSUB  I2cOutByte      ' send register number
 I2cBuf = I2cData.HIGHBYTE
 GOSUB  I2cOutByte      ' send the data - high byte
 I2cBuf = I2cData.LOWBYTE
 GOSUB  I2cOutByte      ' send the data - low byte
 GOSUB  I2cStop
 RETURN

I2CByteRead:

 GOSUB  I2cStart
 I2cBuf = I2cAddr
 GOSUB  I2cOutByte      ' send device address
 I2cBuf = I2cReg
 GOSUB  I2cOutByte      ' send register number
 GOSUB  I2cStart      ' repeated start
 I2cBuf = I2cAddr | 1
 GOSUB  I2cOutByte      ' send device address (with read set)
 I2cAck = 0        ' send Nak
 GOSUB  I2cInByte
 I2cData.LOWBYTE = I2cBuf  ' read the data
 I2cData.HIGHBYTE = 0
 GOSUB  I2cStop
 RETURN

I2CWordRead:

 GOSUB  I2cStart
 I2cBuf = I2cAddr
 GOSUB  I2cOutByte      ' send device address
 I2cBuf = I2cReg
 GOSUB  I2cOutByte      ' send register number
 GOSUB  I2cStart      ' repeated start
 I2cBuf = I2cAddr | 1
 I2cAck = 1        ' send Ack
 GOSUB  I2cOutByte      ' send device address (with read set)
 GOSUB  I2cInByte
 I2cData.HIGHBYTE = I2cBuf  ' read the data
 I2cAck = 0        ' send Nak
 GOSUB  I2cInByte
 I2cData.LOWBYTE = I2cBuf
 GOSUB  I2cStop
 RETURN

I2cOutByte:

 SHIFTOUT SDA, SCL, MSBFIRST, [I2cBuf]
 INPUT  SDA
 HIGH  SCL          ' clock in the ack' bit
 LOW  SCL
 RETURN

I2cInByte:

 SHIFTIN SDA, SCL, MSBPRE, [I2cBuf]
 SDAout = 0
 SDAdir = I2cAck
 HIGH  SCL          ' clock out the ack' bit
 LOW   SCL
 INPUT  SDA
 RETURN

I2cStart ' I2C start bit sequence

 HIGH  SDA
 HIGH  SCL
 LOW  SDA
 LOW  SCL
 RETURN

I2cStop: ' I2C stop bit sequence

 LOW  SDA
 HIGH  SCL
 HIGH  SDA
 RETURN