Const setpoint = 5
Const measure = 6
Const dif = 7

With RCX
.ComPortNo = 1  ' COM port 1
.LinkType = 0   ' 0 = IR
.PBrick = 1  ' 1 = RCX, 0 = CyberMaster
.InitComm          ' Initialise the COM port

.SelectPrgm SLOT3
.BeginOfTask MAIN
    .SetSensorType SENSOR_2, LIGHT_TYPE
    .SetSensorMode SENSOR_2, RAW_MODE, 0
    
    .SetVar setpoint, CON, 1 '1=N,2=NE,3=E,4=SE,5=S,6=SW,7=W,8=NW
    .SetVar measure, CON, 0
    .SetVar dif, CON, 0
    
    .StartTask 1
.EndOfTask 'Main

.BeginOfTask 1
.Loop CON, forever
'North
    .If SENVAL, SENSOR_2, EQ, CON, 863
    .SetVar measure, CON, 1
    .EndIf
    .If SENVAL, SENSOR_2, EQ, CON, 862
    .SetVar measure, CON, 1
    .EndIf
    .If SENVAL, SENSOR_2, EQ, CON, 861
    .SetVar measure, CON, 1
    .EndIf
'North-East
    .If SENVAL, SENSOR_2, EQ, CON, 920
    .SetVar measure, CON, 2
    .EndIf
    .If SENVAL, SENSOR_2, EQ, CON, 919
    .SetVar measure, CON, 2
    .EndIf
    .If SENVAL, SENSOR_2, EQ, CON, 918
    .SetVar measure, CON, 2
    .EndIf
'East
    .If SENVAL, SENSOR_2, EQ, CON, 810
    .SetVar measure, CON, 3
    .EndIf
    .If SENVAL, SENSOR_2, EQ, CON, 809
    .SetVar measure, CON, 3
    .EndIf
    .If SENVAL, SENSOR_2, EQ, CON, 808
    .SetVar measure, CON, 3
    .EndIf
'South-East
    .If SENVAL, SENSOR_2, EQ, CON, 856
    .SetVar measure, CON, 4
    .EndIf
    .If SENVAL, SENSOR_2, EQ, CON, 855
    .SetVar measure, CON, 4
    .EndIf
    .If SENVAL, SENSOR_2, EQ, CON, 854
    .SetVar measure, CON, 4
    .EndIf
'South
    .If SENVAL, SENSOR_2, EQ, CON, 818
    .SetVar measure, CON, 5
    .EndIf
    .If SENVAL, SENSOR_2, EQ, CON, 817
    .SetVar measure, CON, 5
    .EndIf
    .If SENVAL, SENSOR_2, EQ, CON, 816
    .SetVar measure, CON, 5
    .EndIf
'South-West
    .If SENVAL, SENSOR_2, EQ, CON, 830
    .SetVar measure, CON, 6
    .EndIf
    .If SENVAL, SENSOR_2, EQ, CON, 829
    .SetVar measure, CON, 6
    .EndIf
    .If SENVAL, SENSOR_2, EQ, CON, 828
    .SetVar measure, CON, 6
    .EndIf
'West
    .If SENVAL, SENSOR_2, EQ, CON, 787
    .SetVar measure, CON, 7
    .EndIf
    .If SENVAL, SENSOR_2, EQ, CON, 786
    .SetVar measure, CON, 7
    .EndIf
    .If SENVAL, SENSOR_2, EQ, CON, 785
    .SetVar measure, CON, 7
    .EndIf
'North-West
    .If SENVAL, SENSOR_2, EQ, CON, 887
    .SetVar measure, CON, 8
    .EndIf
    .If SENVAL, SENSOR_2, EQ, CON, 886
    .SetVar measure, CON, 8
    .EndIf
    .If SENVAL, SENSOR_2, EQ, CON, 885
    .SetVar measure, CON, 8
    .EndIf
    
'The sensor value is stored in register 'measure'
'the target value in 'setpoint'
.SetVar dif, VAR, measure 'dif=measure-setpoint
.SubVar dif, VAR, setpoint
.If VAR, dif, EQ, CON, 0
    .PlaySystemSound 0
.EndIf
.EndLoop
.EndOfTask
End With