Step motor function writing notes

# ftguzuntypi.py v1.5 tlfong01 2013may31

# *****************************************************************************
# Module - ftguzuntypi.py
# Description - Stepping motor, LED driver
# *****************************************************************************

# *****************************************************************************
# Imports
# *****************************************************************************

import time
import spidev
from subprocess import call

import ftspi
import ftprint

# *****************************************************************************
# Guzunty Pi test functions
# *****************************************************************************

# *****************************************************************************
# Function - Stepping motor
# Description -
# P1 pin assignment
#   P1-01 = Winding 1 (A-)
#   P1-02 = Winding 2 (A+)
#   P1-03 = Winding 3 (B-)
#   P1-04 = Winding 4 (B+)
# Activation sequences
#   WaveSequence = [1, 3, 2, 4]
#   FullStepSequence =  [[1, 3], [1, 4], [2, 4], [2, 3]]
#   HalfStepSequence =  [[1], [1,4], [4], [2,4], [2], [2,3], [3]]
# Unipolar Stepping Motor Switching Sequence
#   Wave sequence = 1 - 3 - 2 - 4 (A-, B-, A+, B+)
#   Full step sequence = 13 - 14 - 24 - 23 (A-B-, A-B+, A+B+, A+B-)
#   Half step sequence  = 13 - 1 - 14 - 4 - 24 - 2 - 23 - 3
#   One step swing = 1 - 3 - 1 - 3 (A-, B-, A-, B-)
# Motor windings list
#   Winding        A-(1)    A+(2)    B-(3)   B+(4)    COM (+5V)
#   28BYJ48        Pink     Orange   Blue    Yellow   Red
#   NPM PF35       Black    Yellow   Brown   Orange   Red
#   PX245          Black    Green    Blue    Red      Yelow/White
# BYJ series geared step motor - 28byj48-12-300-01
#   Rated voltage - 12V
#   Number of phases - 2
#   Resistance per phase 300R
#   Gear reduction ratio - 1:64
#   Step angle - 5.625 degree /64 ??? or / 48
#   Pull-in torque at 500pps - >= 300 gm
#   Pull-in rate - >= 500 pps
#   Detent torque - >= 350
#   Noise - <= 35dB
# Sample call -
# *****************************************************************************

Wave = [0x1, 0x4, 0x2, 0x8]
WaveClockwise = [0x1, 0x4, 0x2, 0x8]
WaveCounterClockwise = list.reverse(WaveClockwise)
Clockwise = 0
CounterClockwise = 1
MilliSeconds50 = 0.05
Byj48stepAngle = 5.625
MotorStateListInit = [0x0f, 0x0f, 0x0f, 0x0f]
MotorStateQuadNibbleWordInit = 0xffff

def MoveStepMotor(motorStateList, motorNumber, stepSequence, stepAngle, stepTime, direction, angularDistance):

    ftprint.PrintDoubleSpaceLine("*** Start MoveStepMotor() ***")  

    print "Motor state list = ", hex(motorStateList[0]), hex(motorStateList[1]), hex(motorStateList[2]), hex(motorStateList[3])
    print "Motor number = ", motorNumber
    print "Step sequence = ", stepSequence
    print "Step angle = ", stepAngle
    print "Step time = ", stepTime
    print "Direction = ", direction
    print "Angular distance = ", angularDistance

    print "Motor state word = ", hex(MotorStateQuadNibbleWordInit)

    spiChannel = spidev.SpiDev()
    spiChannel.open(0, 0)          

    if (direction == Clockwise):
        stepSequence == list.reverse(stepSequence)

    print "Step sequence = ", stepSequence[0], stepSequence[1], stepSequence[2], stepSequence[3]

    # motorStateQuadNibbleWord = 0x0000 | (stepSequence[0]) | (stepSequence[1] << 4) | (stepSequence[2] << 8) | (stepSequence[3] << 12)

    motorStateQuadNibbleWord = 0x2222
 
    print "StateQuadNibbleWord = ", hex(motorStateQuadNibbleWord)

    motorStateHighByte = motorStateQuadNibbleWord >> 8
    motorStateLowByte  = motorStateQuadNibbleWord & 0x00ff
    print "motorStateHighByte = ", hex(motorStateHighByte)
    print "motorStateLowByte = ", hex(motorStateLowByte)

    motorStateQuadNibbleWord = (motorStateQuadNibbleWord & (~(0x000f << (motorNumber * 4)))) | (0x0005 << (motorNumber * 4))

    print "StateQuadNibbleWord = ", hex(motorStateQuadNibbleWord)

    motorStateHighByte = motorStateQuadNibbleWord >> 8
    motorStateLowByte  = motorStateQuadNibbleWord & 0x00ff
    print "motorStateHighByte = ", hex(motorStateHighByte)
    print "motorStateLowByte = ", hex(motorStateLowByte)

    spiChannel.close()

    ftprint.PrintDoubleSpaceLine("*** Stop testing stepping motor N ***")

    return motorStateList


# *** Sample call ***
# ftguzuntypi.MoveStepMotor(motorStateList = ftguzuntypi.MotorStateListInit,
#                           motorNumber = 1,
#                           stepSequence = ftguzuntypi.Wave,
#                           stepAngle = ftguzuntypi.Byj48stepAngle,
#                           stepTime = ftguzuntypi.MilliSeconds50,
#                           direction = ftguzuntypi.Clockwise,
#                           angularDistance = 10)

# *** Sample output ***
# *** Start Program - FongToy v1.4 tlfong01 2013may31 ***
# *** Start MoveStepMotor() ***
# Motor state list =  0xf 0xf 0xf 0xf
# Motor number =  1
# Step sequence =  [1, 4, 2, 8]
# Step angle =  5.625
# Step time =  0.05
# Direction =  0
# Angular distance =  10
# Motor state word =  0xffff
# Step sequence =  8 2 4 1
# StateQuadNibbleWord =  0x2222
# motorStateHighByte =  0x22
# motorStateLowByte =  0x22
# StateQuadNibbleWord =  0x2252
# motorStateHighByte =  0x22
# motorStateLowByte =  0x52
# *** Stop testing stepping motor N ***

.END