'*************************************************************************
'*                        <3-Phase motor controller>                     *
'*                                    by                                 *
'*                          Dr.Godfried-Willem RAES                      *
'*                        Stamp2 Hardware version 1.0                    *
'*                         Filename : <3Phase.bs2>                       *
'*                             Code version 1.0                          *
'*************************************************************************
' 15.06.1998: designed for Laukhuff compressor motor speed control.
'             speed should vary -20% to + 30%.
'             With no data applied, the generated three phase voltage
'             should be 50Hz.
' 16.07.2001: reconsidered.
' 18.07.2001: Now runs under NT with new Parallax editor.

' DECLARATIONS:
Centrobyte VAR  byte     ' incoming byte, from midi microcontroller
Motors VAR nib           ' 3-bits is enough, we use the lower 3 bits
Tempo VAR word           ' in 2 microsecond units
Ref50 VAR word           ' 50Hz frequency reference
Robot VAR word           ' not yet in use...

' INITIALISATION:
                    ' parallel input bits 0 to 7
                    ' these bits are mapped on midi notes 0-7
                    ' make this byte an input:
DIRL = 0
                    ' pins 8 to 11 are not used. We configure
                    ' them as outputs:
DIRC = $F
              'DIR12 = 1 :' phase U output
              'DIR13 = 1 :' phase V output
              'DIR14 = 1 :' phase W output
              'DIR15 = 1 :' not used bit
              ' these pins feed an optocoupler, in its turn connected to
              ' the gates of 3 power mosfets.
DIRD = $F

' Initialisation of variables:

Centrobyte = INL    :' low byte is incoming info
Robot = 1           :' default is Robot ON
Motors = 0          :' bit pattern for 3-phase current in bits 0-2
Ref50 = 1666        :' (20.000 microseconds / 6)  / 2
Tempo = 1666        :' this value needs trimming.

' START OF RUN-CODE:*****************************************************
Begin:
     Centrobyte = INL
     GOSUB FreqAlgo
     Motors = $5               :' 60 graden
     OUTD = Motors
     PAUSE tempo
     Centrobyte = INL
     GOSUB FreqAlgo
     Motors = $4               :' 120 graden
     OUTD = Motors
     PAUSE tempo
     Centrobyte = INL
     GOSUB FreqAlgo
     Motors = $6               : ' 180 graden
     OUTD = Motors
     PAUSE tempo
     Centrobyte = INL
     GOSUB FreqAlgo
     Motors = $2               : ' 240 graden
     OUTD = Motors
     PAUSE tempo
     Centrobyte = INL
     GOSUB FreqAlgo
     Motors = $3               : ' 300 graden
     OUTD = Motors
     PAUSE tempo
     Centrobyte = INL
     GOSUB FreqAlgo
     Motors = $1               : ' 360 graden
     OUTD = Motors
     PAUSE tempo
Goto Begin

FreqAlgo:
     IF Centrobyte = 0 THEN Geval0
     IF Centrobyte < 128 THEN GevalSneller
     IF Centrobyte > 127 THEN GevalTrager
Geval0:
     tempo = Ref50
     RETURN
GevalSneller:
     tempo = Ref50 - (Centrobyte * 3)
     RETURN
GevalTrager:
     Centrobyte = Centrobyte - 127
     tempo = Ref50 + (Centrobyte * 4)
     RETURN
END