MCP23017 Bank 0 setting problem solved

MCP23017 Bank 0 setting problem solved

Earlier I found that I could not set Bank 0 in MCP23017 because it cause wrong reading of GPIO register. I remember that I could do the similar thing in MCP23008, I read the datasheet  again and found that I misunderstood the datasheet on port A port B registers offset "sequentially".  So I made the corrections but still it does not work.  Then I looked at my code again and found that I made a careless mistake in the register offset tuple in mixing up decimal and hexidecimal values.  So I rewrite the offset tuple and now everything works OK.



# * MCP23008/MCP23017 register address offsets index Bank 0 *
InputOutputDirection = 0
InputPolarity = 1
InterruptEnable = 2
DefaultValue = 3  
CompareMode = 4
BankInterruptPinMode = 5
PullUp = 6
InterruptFlag = 7
InterruptCapture = 8
PortStatus = 9
OutputLatch = 10


# * MCP23008/MCP23017 Bank0/Bank1 register address offset arrays *
               
RegisterAddressOffsetArrayBank0 = [0x00, 0x02, 0x04, 0x06, 0x08, 0x0a, 0x0c, 0x0e, 0x10, 
                                   0x12, 0x14,        
                                   0x01, 0x03, 0x05, 0x07, 0x09, 0x0b, 0x1d, 0x0f, 0x11,  
                                   0x13, 0x15]


.END

# *****************************************************************************
# !/usr/bin/python2.7
#
# Program
#   FPL3.py - 2013feb
# Author
#   tlfong01 <http://tlfong01.blogspot.hk/> 
# Configuration
#   Raspberry Pi Bv2 512MB, Raspbian Wheezy, Python 2.7.3, RPI.GPIO 0.4.1a 
# License
#   GNU GPLv3
# Warranty 
#   For hobbist only.  Use at your own risk.  There is not  any warranty,
#   not even implied warranty of merchantability or fitness for any 
#   particular purpose
# System development methodologies / Programming paradims 
#   Software prototyping, Test-driven (TDD), Iterative and incremental (IID),
#   Agile / Functional Programming (FP), Object Oriented Programming (OOP)
# Specifications summary
#   5V0max 50mA, 3V3max 300mA, PerPinMax 17mA source 12mA sink
# References 
#   IO Expander
#     1. Mcirochip Application Notes AN1043 (GPIO Expander)
#   Matrix keypad
#     2. Microchip Application Notes AN1081 (Matrix Keypad)
#   LCD1602
#     3. ShenZhen YaJingDa Electronics YJD1602A-1 datasheet (2007-09-08)
#     4. PowerTip PC-1602F datasheet (11/10/2004)
#     5. Sitronix ST7066U Dot Matrix LCD Controller/Driver datasheet (01/03/01)
# Raspberry Pi communities
#   eLinux -  http://elinux.org/RPi_Community
#   element14 - http://www.element14.com/community/groups/raspberry-pi
# *****************************************************************************

# 0. Contents ******************************************************************
#
#  1. Program title
#  2. Python imports
#  3. RPi GPIO pin assignment, MCP230xx register base assignment
#  4. Global constants
#  5. GPIO Functions 
#  6. Debugging and documentation functions (beep, print bit/byte, message)
#  7. IO Expander MCP23008, MCP23017
#  8. Decimal keypad
#  9. LCD - LCD1602. LCD2004
# 10. Stepping motor - unlpolar steppers 28BYJ48/NPM-PF35/PX245
# 11. Demultiplexor
# 12. Old test functions 
# 13. Main program

# 1. Program Title ************************************************************

ProgramTitle = "FPL v3.00 TL Fong 2013feb04"

# 2 Python imports ***********************************************************

import sys
import time
import select
import RPi.GPIO as GPIO
import smbus 

smBus1 = smbus.SMBus(1) 

# 3. GPIO and IO Expander pin/address assignments *****************************

# * MCP230xx Register base addresses *

# * System A *

MCP23017BaseAddress1 = 0x22 # LED, button
MCP23008BaseAddress1 = 0x24 # stepping motors
MCP23008BaseAddress2 = 0x25 # keypad
MCP23008BaseAddress3 = 0x26 # LCD1602

# * System B *

MCP23017BaseAddressSystemB1 = 0x20 # decimal/hexdecimal keypad

# * GPIO pin numbering *

GPIO.setmode(GPIO.BOARD) # Use RPi GPIO numbering, Not BCM numbering
GPIO.setwarnings(False)  # Disable linux's "pin already in use warning"

# * RPi GPIO pin numbering *

# P1-02 5V, P1-04 5V, P1-06 Gnd
# P1-01 3V3, P1-03 I2C SDA1, P1-05 I2C SCL1
# P1-08 UART TxD (MCP23017 Reset)
# P1-10 UART RxD (MCP23017 INTB)
# P1-12 RPi GPIO_GEN1 (BCM18) LED (P1-12 > LED > 330R > Gnd)
# P1-14 Gnd
# P1-16 GPIO_GEN4 - Buzzer, 3V3 5mA (P1-16 > Buzzer > Gnd) 
# P1-18 GPIO_GEN5 Button (3V3 > 10K > Contact 1/2 > 330R > Gnd)
# P1-20 Gnd
# P1-22 GPIO_GEN6 - MCP23008 INT / MCP23017 INTA   

RPiGPIOgen1 = 12 # Brown  (P1-12, BCM GPIO 18) LED
RPiGPIOgen4 = 16 # Yellow (P1-16, BCM GPIO 23) Buzzer
RPiGPIOgen5 = 18 # Green  (P1-18, BCM GPIO 24) Button
RPiGPIOgen6 = 22 # Blue   (P1-22, BCM GPIO 25) IOx/keypad interrupt

RPiTxD = 8 # Orange (P1-08) UART TxD
RPiRxD = 10 # Yellow (P1-10) UART RxD

# * peripherals pins assignment *

LEDpin = RPiGPIOgen1
BuzzerPin = RPiGPIOgen4 
ButtonPin = RPiGPIOgen5
TxDpin = RPiTxD
RxDpin = RPiRxD 


# * GPIO input/output pins list *

OutputPinList = [LEDpin, BuzzerPin, TxDpin]
InputPinWithNoPullUpList = [ButtonPin]
InputPinWithPullUpList = [RPiGPIOgen6]


# 4. Global constants *********************************************************

# * Loop counters *
TwoTimes = 2
FourTimes = 4
EightTimes = 8
TenTimes = 10
TwentyTimes = 20
FiftyTimes = 50
OneHundredTimes = 100
TwoHundredTimess = 200
FourHundredTimes = 400

# * Elapse times *
TwentyMilliSeconds = 0.02
FiftyMilliSeconds = 0.05
OneHundredMilliSeconds = 0.1
TwoHundredMilliSeconds = 0.2
TenthSecond = 0.1
QuarterSecond = 0.25
HalfSecond = 0.5
OneSecond = 1
OneAndHalfSeconds = 1.5
TwoSeconds = 2

# * On/Off times *
OnTime = TenthSecond
OffTime = QuarterSecond
ButtonDebouncingTime = QuarterSecond
TestTime = FiftyMilliSeconds

OnTime = 0.1
OffTime = 0.25

# 5. GPIO Functions ***********************************************************
# * Local constants *

# * Nibble naming * 
LowNibble = 0
HighNibble = 1
BothNibble = 2 # full byte of 8 bits

# * Nibble constants *
HighNibble1LowNibble0 = 0xf0
HighNibble0LowNibble1 = 0x0f

# * LED and buzzer states *
Off = False
On = True

# * Button states *
ButtonPressed = False
ButonReleased = True

# * Interrupt states *
Low = False
High = True


# * Setup, read/write GPIO pins *
setupOutputPin = lambda oPin: GPIO.setup(oPin, GPIO.OUT) # set GPIO pin as output 

setupInputPinWithNoPullUp = lambda iPin: GPIO.setup(iPin, GPIO.IN, pull_up_down=GPIO.PUD_OFF) # set GPIO pin as input, no pull up

setupInputPinWithPullUp = lambda iPin: GPIO.setup(iPin, GPIO.IN, pull_up_down=GPIO.PUD_UP) # set GPIO pin as input, with pull up

writeOutputPin = lambda oPin, oValue: GPIO.output(oPin, oValue) # write value to output pin

setupWriteOutputPin = lambda oPin, oValue: (setupOutputPin(oPin), writeOutputPin(oPin, oValue)) # set and write

readInputPin = lambda iPin: GPIO.input(ButtonPin) # read value from input pin

def SetupGPIOpins(outputPinList, inputPinWithNoPullUpList, inputPinWithPullUpList): # set up GPIO pins in InputPinList and OutputPinList
    for oPin in outputPinList:
       setupWriteOutputPin(oPin, Off)
    for iPin in inputPinWithNoPullUpList:
        setupInputPinWithPullUp(iPin)
    for iPin in inputPinWithPullUpList:
        setupInputPinWithPullUp(iPin)

def SetupGPIO(): # set up GPIO pins
     SetupGPIOpins(OutputPinList, InputPinWithNoPullUpList, InputPinWithPullUpList )

# * pulse/echo/toggle functions * 

def pulsePin(oPin, onTime, offTime): # blink LED or beep buzzer
    writeOutputPin(oPin, On)
    time.sleep(onTime)
    writeOutputPin(oPin, Off)    
    time.sleep(offTime)

def echoPin(iPin, oPin): # echo input pin to output pin, e.g. button to LED or buzzer
    while True:
        if readInputPin(iPin) == ButonReleased:
            pass
        else:
            pulsePin(oPin, OnTime, OffTime)
            break
        continue

def togglePin(oPin, toggleTime): # toggle pin
    writeOutputPin(oPin, On)
    time.sleep(toggleTime)
    writeOutputPin(oPin, Off)    
    time.sleep(toggleTime)

# * Test Buzzer, LED, Button *
def TestBuzzer(): # beep 4 times
    SetupGPIO()
    for i in range (FourTimes):
        pulsePin(BuzzerPin, OnTime, OffTime)

def TestLED(): # blink 4 times
    SetupGPIO()
    for i in range (FourTimes): 
        pulsePin(LEDpin, OnTime, OffTime)

def TestButtonEchoBuzzer(): #
    SetupGPIO()
    print "\n", "Press button 4 times.", "\n"
    for i in range (FourTimes):
        echoPin(ButtonPin, BuzzerPin)          

def TestButtonEchoLED(): #
    SetupGPIO()
    print "\n", "Press button 4 times.", "\n"    
    for i in range (FourTimes):
        echoPin(ButtonPin, LEDpin)

# GPIO Interrupt function !!! not yet tested !!!
def TestInterruptPinFallingEdgeDetection(): # !!! Not tested !!!
    GPIO.cleanup() # set all input pins no pull up, disable all interutp detection setting
    SetupGPIO()   
    GPIO.set_low_event(InterruptPin) # set up low level detection 

    for i in range(30):
        if GPIO.event_detected(InterruptPin):
   break
        else:
            print "No interrupt detected.", i
            time.sleep(1)
   continue

    GPIO.set_low_event(InterruptPin, enable = False)  # disable detection
    print "End of test, or interrupt detected"


# 5. Debugging and documentation functions ************************************

# * Data bit processing and printing *

def SetDataBit(dataByte, bitIndex):
    setDataByte = 0x01 << bitIndex
    dataByte = dataByte | setDataByte
    return dataByte

def ResetDataBit(dataByte, bitIndex):
    resetDataByte = ~(0x01 << bitIndex)
    dataByte = dataByte & resetDataByte
    return dataByte

def ConvertIntegerToFourBitPattern(integer):
    FourBitPattern = [""]
    for k in range(4): 
        FourBitPattern = [i+j for i in ['0','1'] for j in FourBitPattern]
    return FourBitPattern[integer]

def ConvertIntegerToEightPattern(integer):
    EightBitPattern = [""]
    for k in range(8): 
        EightBitPattern = [i+j for i in ['0','1'] for j in EightBitPattern]
    return EightBitPattern[integer]

def PrintEightBitPattern(message, dataByte):
    eightBitPattern = ConvertIntegerToEightPattern(dataByte)
    print message, eightBitPattern

def PrintFourBitPattern(message, dataByte):
    fourBitPattern = ConvertIntegerToFourBitPattern(dataByte)
    print message, fourBitPattern

def Beep(count):
    for i in range(count):
        pulsePin(BuzzerPin, OnTime, OffTime)
    
def StartBeep():
    Beep(2)
    time.sleep(1)

def StopBeep():
    Beep(2)

def OneBeep():
    Beep(1)

def FourBeeps():
    Beep(4)

def StartProgram():
    message =  "\n" + "*** Start Program - " + ProgramTitle + " *******************************" + "\n"
    SetupGPIO()
    StartBeep()
    print message

def StopProgram():
    message =  "\n" + "*** Stop Program **************************************************************" + "\n"
    StopBeep()
    print message

# 7. IO Expander MCP23008, MCP23017 *******************************************

# * Local constants *

# * Port type *
PortA = 0
PortB = 1

# * MCP23008/MCP23017 register address offsets index Bank 0 *
InputOutputDirection = 0
InputPolarity = 1
InterruptEnable = 2
DefaultValue = 3  
CompareMode = 4
BankInterruptPinMode = 5
PullUp = 6
InterruptFlag = 7
InterruptCapture = 8
PortStatus = 9
OutputLatch = 10

# * Data constant bytes *

AllOutputByte = 0x00
AllInputByte = 0xff
AllHighByte = 0xff
AllLowByte =  0x00
AllPullUpByte = 0xff

# * Direction setting bytes *
HalfHighHalfLow = 0xf0
HalfLowHalfHigh = 0x0f
Nibble1HighNibble2Low = 0xf0
Nibble1LowNibble2High = 0x0f
HighNibbleInputLowNibbleOutput = 0xf0

# * MCP23008/MCP23017 Bank0/Bank1 register address offset arrays *
               
RegisterAddressOffsetArrayBank0 = [0x00, 0x02, 0x04, 0x06, 0x08, 0x0a, 0x0c, 0x0e, 0x10, 0x12, 0x14,        
                                   0x01, 0x03, 0x05, 0x07, 0x09, 0x0b, 0x1d, 0x0f, 0x11, 0x13, 0x15]

# * Setup input/output ports *

def SetupMCP23008PortAllOutput(registerBaseAddress):
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, InputOutputDirection, PortA, AllOutputByte)

def SetupMCP23017BothPortAllOutput(registerBaseAddress):
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, InputOutputDirection, PortA, AllOutputByte)
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, InputOutputDirection, PortB, AllOutputByte)

def SetupMCP23017PortAoutputPortBinputPullUp(registerBaseAddress):
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, InputOutputDirection, PortA, AllOutputByte)
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, InputOutputDirection, PortB, AllInputByte)
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, PullUp, PortB, AllPullUpByte)

# * Read/write registers *

def WriteDataByte(registerBaseAddress, registerAddressArray, dataRegisterIndex, portType, dataByte):
    if (portType == PortA) | (portType == PortA):
       addressOffset = registerAddressArray[dataRegisterIndex]
    if (portType == PortB):
       addressOffset = registerAddressArray[dataRegisterIndex + 11]
    smBus1.write_byte_data(registerBaseAddress, addressOffset, dataByte)

def ReadDataByte(registerBaseAddress, registerAddressArray, dataRegisterIndex, portType):
    if (portType == PortA):
       addressOffset = registerAddressArray[dataRegisterIndex]
    if (portType == PortB):
       addressOffset = registerAddressArray[dataRegisterIndex + 11]
    dataByte = smBus1.read_byte_data(registerBaseAddress, addressOffset)
    return dataByte

def ReadUpperNibble(registerBaseAddress, registerAddressArray, dataRegisterIndex, portType):
    dataByte = ReadDataByte(registerBaseAddress, registerAddressArray, dataRegisterIndex, portType)
    upperNibble = dataByte >> 4
    return upperNibble

def ReadLowerNibble(registerBaseAddress, registerAddressArray, dataRegisterIndex, portType):
    dataByte = ReadDataByte(registerBaseAddress, registerAddressArray, dataRegisterIndex, portType)
    lowerNibble = dataByte & 0x0f
    return lowerNibble

# * Config interrupts *
def EnableInterruptOnChangeHighNibble(registerBaseAddress): 
    EnableInterruptHighNibble = 0xf0
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, InterruptEnable, PortA, EnableInterruptHighNibble)

def DisableInterruptOnChangeHighNibble(registerBaseAddress): 
    DisableInterruptHighNibble = 0x00
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, InterruptEnable, PortA, DisableInterruptHighNibble)

def SetInterruptOnChangeDefaultHighNibble(registerBaseAddress): 
    DefaultValueByte = 0xf0 
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, InterruptOnChangeDefaultValue, PortA, DefaultValueByte)

def SetInterruptOnChangeCompareDefaultHighNibble(registerBaseAddress): 
    InterruptOnChangeDefaultValueHighNibble = 0xf0 # GP4~7 change from default value will cause interrupt
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, CompareMode, PortA, InterruptOnChangeDefaultValueHighNibble)

def SetInterruptOutputPushPull(registerBaseAddress): # interrupt pin open drain, no auto add inc, no slew rate
    PushPull  = 0b00111010 # 0x32, seq/slew disabled, interrupt output drive drive (push pull) active High
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, PushPullOpenDrain, PortA, PushPull)

def SetInterruptOutputOpenDrain(registerBaseAddress): # interrupt pin open drain, no auto add inc, no slew rate
    OpenDrain = 0b00111000 # 0x34, seq/slew disabled, interrupt output open drain (don't care active High or Low)
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, PushPullOpenDrain, PortA, OpenDrain)

# * Poll interrupts *
def ReadInterruptFlagHighNibble(registerBaseAddress): 
    interruptFlagByte = ReadDataByte(registerBaseAddress,  RegisterAddressOffsetArrayBank0, InterruptFlag, PortA)  
    interruptFlagNbble = interruptFlagByte >> 4
    return interruptFlagNibble   
    
def ReadInterruptCaptureHighNibble(registerBaseAddress): 
    interruptCaptureByte = ReadDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, InterruptCapture, PortA)    
    interruptCaptureNibble = interruptCaptureByte >> 4
    return interruptCaptureNibble  

def ReadInterruptCaptureLowNibble(registerBaseAddress): 
    interruptCaptureByte = ReadDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, InterruptCapture, PortB)    
    interruptCaptureNibble = interruptCaptureByte & 0x0f
    return interruptCaptureNibble  

def DetectOneInterrupt(registerBaseAddress): # !!! NOT tested !!!   
    interruptFlagNibble = ReadInterruptFlagHighNibble(registerBaseAddress)
    interruptCaptureNibble = ReadInterruptCaptureHighNibble(registerBaseAddress)
    print "Interrupt capture high nibble = ", ConvertIntegerToFourBitPattern(interruptCaptureNibble) 
    print "Interrupt capture high nibble = ", ConvertIntegerToFourBitPattern(interruptCaptureNibble) 
    ClearInterruptOnChangeHighNibble(registerBaseAddress) # !!! clear interrupt !!!
    time.sleep(2)

# * Test port toggling, poll interrupts *

def ToggleMCP23008GP(registerBaseAddress, toggleTime, toggleCount):
    SetupMCP23008PortAllOutput(registerBaseAddress)
    for i in range(toggleCount):
        WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, OutputLatch, PortA, AllHighByte) 
time.sleep(toggleTime)
        WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, OutputLatch, PortA, AllLowByte) 
  time.sleep(toggleTime)

def ToggleMCP23017GP(registerBaseAddress, toggleTime, toggleCount):
    SetupMCP23017BothPortAllOutput(registerBaseAddress)
    for i in range(toggleCount):
        WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, OutputLatch, PortA, AllHighByte)
        WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, OutputLatch, PortB, AllHighByte)
time.sleep(toggleTime)
        WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, OutputLatch, PortA, AllLowByte)
        WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, OutputLatch, PortB, AllLowByte)
  time.sleep(toggleTime)

def ToggleMCP23017B1(registerBaseAddress, toggleTime, toggleCount):
    SetupMCP23017BothPortAllOutput(registerBaseAddress)

    for i in range(toggleCount):
        WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, OutputLatch, PortA, AllHighByte)
        WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, OutputLatch, PortB, AllHighByte)
time.sleep(toggleTime)
        WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, OutputLatch, PortA, AllLowByte)
        WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, OutputLatch, PortB, AllLowByte)
  time.sleep(toggleTime)

def TestToggleMCP23008GP():
    ToggleMCP23008GP(MCP23008BaseAddress1, ToggleTime, ToggleCount) 

def TestToggleMCP23017GP():
    ToggleMCP23008GP(MCP23017BaseAddress1,  ToggleTime, ToggleCount)

def TestDetectInterrupt(count): # !!! NOT Tested !!!
    RegisterBaseAddress =  MCP23008BaseAddress2
    SetupKeypadInterruptHighNibbleCompareDefaultValueOpenDrainOutput(RegisterBaseAddress)
    for i in range(count): 
        DetectOneInterrupt(RegisterBaseAddress)

# * System B test functions *

def TestToggleMCP23017SystemB1(count): 
    ToggleTime = 0.5
    ToggleCount = 4

    registerBaseAddress = MCP23017BaseAddressSystemB1
    SetupMCP23017PortAoutputPortBinputPullUp(registerBaseAddress)

    for i in range(count):
        WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, OutputLatch, PortA, AllHighByte)
time.sleep(ToggleTime)
        WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, OutputLatch, PortA, AllLowByte)
  time.sleep(ToggleTime)

def TestReadMCP23017SystemB1(count):
    registerBaseAddress = MCP23017BaseAddressSystemB1
    SetupMCP23017PortAoutputPortBinputPullUp(registerBaseAddress)
    for i in range(count):
        dataByte = ReadDataByte(MCP23017BaseAddressSystemB1, RegisterAddressOffsetArrayBank0, PortStatus, PortB)
        PrintEightBitPattern("Data byte read = ", dataByte)
        time.sleep(1) 

# 8. Decimal keypad *********************************************************** 

# *****************************************************************************
# * Decimal keypad using MCP23017 v2.18 TL Fong last update 2013feb03 *
# *****************************************************************************

# * Configuration *
# MCP23017 GPIO direction - Port A = output, Port B = input
# Keypad pin assignment - GPA0~A2 = Col0~2, GPB0~B3 = Row0~3

Keypad017InterruptPin = RPiGPIOgen6

# * Local constants *
# * MCP23017 stateTuple indexes and default values *
RegisterBaseAddressIndex = 0
OutputLatchRegisterIndex = 1
PortStatusRegisterIndex = 2
InterruptCaptureRegisterIndex = 3
InterruptFlagRegisterIndex = 4

RegisterBaseAddress = MCP23017BaseAddressSystemB1
OutputLatchRegisterResetValue = 0x00
PortStatusRegisterResetValue = 0x00
InterruptCaptureRegisterResetValue = 0x00
InterruptFlagRegisterResetValue = 0x00

MCP23017StateTuple = RegisterBaseAddress, OutputLatchRegisterResetValue, \
                     InterruptCaptureRegisterResetValue, InterruptFlagRegisterResetValue

# * Polling modes *
NoPollJustGetKeyEverySecond = 0
PollRowStatusNibble = 1
PollInterruptCaptureNibble = 2
PollRPiGPIOgen6Interrupt = 3

# * Setup keypad *
def SetupKeypad017(stateTuple):
     registerBaseAddress = stateTuple[RegisterBaseAddressIndex]
     SetupMCP23017PortAoutputPortBinputPullUp(registerBaseAddress)
     SetupKeypad017Interrupt(registerBaseAddress) # buggy !!!!!!!!!!
     ClearKeypad017Interrupt(registerBaseAddress) 
     WriteKeypad017ColumnsAllLow(registerBaseAddress)
     return stateTuple  

# * Setup/Clear/Check keypad interrupt *

def SetupKeypad017Interrupt(registerBaseAddress):
    SetKeypad017InterruptEnable(registerBaseAddress) 
    SetKeypad017DefaultValue(registerBaseAddress) 
    SetKeypad017EnableCompareDefaultValue(registerBaseAddress)  
    SetKeypad017BankInterruptDriverMode(registerBaseAddress) 

def SetKeypad017InterruptEnable(registerBaseAddress): 
    EnableInterruptLowNibble = 0x0f
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, InterruptEnable, PortB, EnableInterruptLowNibble)

def SetKeypad017DefaultValue(registerBaseAddress): 
    DefaultValueByte = 0x0f # row status nibble is all bits high if no key pressed  
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, DefaultValue, PortB, DefaultValueByte)

def SetKeypad017EnableCompareDefaultValue(registerBaseAddress): 
    InterruptOnChangeDefaultValueLowNibble = 0x0f # GPB0~3 change from default value will cause interrupt
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, CompareMode, PortB, InterruptOnChangeDefaultValueLowNibble)

def SetKeypad017BankInterruptDriverMode(registerBaseAddress): 
    # bit 7 = 0 (Bank = 0, reg with each port are in the same bank (addresses are sequential))
    # bit 6 = 0 (No mirror, INTA and INTB independent)
    # bit 5 = 1 (Sequential operation disabled)
    # bit 4 = 1 (Slew rate disabled)
    # bit 3 = 0 (Disable MCP23S17 address pins, Don't care for MCP23017)
    # bit 2 = 0 (Interrupt driver push pull, no open drain)
    # bit 1 = 1 (Interrrupt active high)
    # bit 0 = 0 (Unimplemented, read as 0)
    # 0b00110010 = 0x32
    # POR/RST = 0x00
    # Bank0DriverPushPullHighActive = 0x32
    Bank0DriverPushPullHighActive = 0x00
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, BankInterruptPinMode, PortB, Bank0DriverPushPullHighActive)

def ClearKeypad017Interrupt(registerBaseAddress):
    WriteAllColumnsLow(registerBaseAddress)
    time.sleep(0.5)
    dummyRead = ReadInterruptCaptureLowNibble(registerBaseAddress) 

#def ReadKeypad017InterruptPin(interruptPin):
#    interruptStatus = readInputPin(interruptPin)
#    return interruptStatus

# * Write columns *

def WriteKeypad017Columns(registerBaseAddress, columnDataByte):    
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, OutputLatch, PortA, columnDataByte)

def WriteKeypad017ColumnsAllLow(registerBaseAddress):
    WriteKeypad017Columns(registerBaseAddress, AllLowByte)

# * Read rows *

#def GetKeypad017RowDataByte(registerBaseAddress): 
#    rowDataByte = ReadDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, PortStatus, PortB)
#    return rowDataByte

#def GetKeypad017RowDataNibble(registerBaseAddress): 
#    rowDataByte = GetKeypad017RowDataByte(registerBaseAddress)
#    PrintEightBitPattern("Row pattern = ", rowDataByte) 
#    rowDataNibble = rowDataByte & 0x0f
#    # PrintFourBitPattern("Row pattern = ", rowDataNibble) 
#    return rowDataNibble

def GetKeypad017RowDataNibble(registerBaseAddress): 
    rowDataByte = ReadDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, PortStatus, PortB)
    rowDataNibble = rowDataByte & 0x0f
    return rowDataNibble

# * Get Row Number, Column Number, and Key Number *

def GetKeypad017RowNumber(registerBaseAddress):
    RowDataNibbleTuple = 0b1110, 0b1101, 0b1011, 0b0111, 0b1111, 0b0000 
    rowDataNibble = GetKeypad017RowDataNibble(registerBaseAddress)

    # *** Begin debugging *****************************************************
    # rowDataNibble = 0b1011 
    # *** End debugging *******************************************************

    # *** Begin debugging *****************************************************    
    PrintFourBitPattern("Row pattern = ", rowDataNibble) 
    rowNumber = RowDataNibbleTuple.index(rowDataNibble)
    print ("Row number = ", rowNumber)
    # *** End debugging *******************************************************

    rowNumber = RowDataNibbleTuple.index(rowDataNibble)
    return rowNumber

def GetKeypad017ColumnNumber(registerBaseAddress):
    ColumnNibbleTuple = 0b1110, 0b1101, 0b1011
    NoKeyPressNibble = 0b1111    
    for columnNibble in (ColumnNibbleTuple):  
        WriteKeypad017Columns(registerBaseAddress, columnNibble) 
        rowDataNibble = GetKeypad017RowDataNibble(registerBaseAddress)
        if rowDataNibble != NoKeyPressNibble:
   break

    # *** Begin debugging *****************************************************
    # columnNibble = 0b1101 
    # columnNumber = ColumnNibbleTuple.index(columnNibble)
    # PrintFourBitPattern("Column pattern = ", columnNibble) 
    # print ("Column number = ", columnNumber)
    # *** End debugging *******************************************************

    columnNumber = ColumnNibbleTuple.index(columnNibble)
    return columnNumber

def GetKeypad017KeyNumber(registerBaseAddress):
    rowNumber = GetKeypad017RowNumber(registerBaseAddress)
    columnNumber = GetKeypad017ColumnNumber(registerBaseAddress)
    keyNumber = (rowNumber * 3) + (columnNumber + 1) 
    return keyNumber

# * Get keys *

def GetKeypad017Key(registerBaseAddress, checkPressingKeyMode): 
    if (checkPressingKeyMode == NoPollJustGetKeyEverySecond): 
        print "Read key every second"
time.sleep(1)
# LoopUntilOneSecondEnded()

    elif (checkPressingKeyMode == PollRowStatusNibble):   
        print "Polling Gpio"
        LoopUntilKeypad017RowDataNibbleChange(registerBaseAddress) 

    elif (checkPressingKeyMode == PollInterruptCaptureNibble):  
        # print "Polling Interrupt"
        LoopUntilKeypad017InterruptPinLow(registerBaseAddress, Keypad017InterruptPin)         

    elif (checkPressingKeyMode == PollRPiGPIOInterrupt):  
        pass

    keyNumber = GetKeypad017KeyNumber(registerBaseAddress)
    return keyNumber

def GetKeypad017KeySequence(stateTuple, checkPressingKeyMode, count): 
    registerBaseAddress = stateTuple[RegisterBaseAddressIndex]
    for i in range (count):        
        OneBeep() 
keyNumber = GetKeypad017Key(registerBaseAddress, checkPressingKeyMode)
        print "Key", i + 1, " = ", keyNumber
    return stateTuple  


# * No polling, just read key at the end of each second *
def LoopUntilOneSecondEnded():
    time.sleep(1)

# * Poll row status *
def LoopUntilKeypad017RowDataNibbleChange(registerBaseAddress): 
    WriteKeypad017Columns(registerBaseAddress, AllLowByte)
    NoKeyPressedNibble = 0xf
    rowDataNibble = NoKeyPressedNibble 
    while (rowDataNibble == NoKeyPressedNibble):
        rowDataNibble = GetKeypad017RowDataNibble(registerBaseAddress)        
    time.sleep(0.05) # debouncing time 50mS

# * Poll Interrupt Capture Register *
def LoopUntilKeypad017InterruptCaptureRegisterChange(registerBaseAddress): # ICP0~3 not all high
    NoKeyPressRowStatusNibble = 0xf
    interruptCaptureNibble = NoKeyPressRowStatusNibble
    while (interruptCaptureNibble == NoKeyPressRowStatusNibble):
        interruptCaptureByte = ReadDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, InterruptCapture, PortB)
        PrintEightBitPattern("Interrupt Capture Byte = ", interruptCaptureByte) 
        interruptCaptureNibble = interruptCaptureByte & 0x0f
        PrintFourBitPattern("Interrupt Capture Nibble = ", interruptCaptureNibble) 
time.sleep(1)
    
    time.sleep(0.05) # debouncing time 50mS

# * Poll MCP23017 interrupt *
def LoopUntilKeypad017InterruptPinLow(registerBaseAddress, interruptPin):
    ClearKeypadInterrupt(registerBaseAddress)
    interruptPinState = readInputPin(interruptPin)
    #print "interruptPinState = ", interruptPinState
    while (interruptPinState == True):
       interruptPinState = readInputPin(interruptPin) 
       #print "interruptPinState = ", interruptPinState
       #time.sleep(1)
    #print "interruptPinState = ", interruptPinState
    time.sleep(0.05) # debouncing time 50mS


# * Test MCP23017 Decimal keypad *

def TestKeypad017(checkPressingKeyMode, keyCount):   
    stateTuple = MCP23017StateTuple
    stateTuple = SetupKeypad017(stateTuple) 
    stateTuple = GetKeypad017KeySequence(stateTuple, checkPressingKeyMode, keyCount)




# *****************************************************************************
# * Decimal keypad using MCP23008 * TL Fong 2013feb01
# *****************************************************************************

# * Function descriptions *

# SetupKeypad(registerBaseAddress)
# Assign GP0~3 as output (Col0~2, Col3 n.c), GP4~7 input (Row0~3)

# WriteAllColumnsLow(registerBaseAddress)
# Set all column outputs (GP0~2 actually, GP3 dummy)

# LoopUntilGpioPortHighNibbleChange(registerBaseAddress)
# Loop until GPIO register's GP4~7 not all High (some key pressed)

# LoopUntilInterruptCaptureHighNibbleChange(registerBaseAddress)
# Loop until INTCAP register's ICP4~7 not all High (some key pressed)

# Keypad scanning procedure version 1.0
# 1. Set 3 column ports GP0, GP1, GP2 as output (GP3 don't care)
# 2. Set 4 row ports GP4, GP5, GP6, GP7 as input
# 3. Write Low to all column ports
# 4. Wait until any key pressed (pooling or interrupt)
# 5. Find rowNumber and column number
# 6. Calculate key number

# * keypad base address and smBus setting *

KeypadRegisterBaseAddress = MCP23008BaseAddress2
KeypadSmBus = smBus1

PollGpioRegister = 0
PollKeypadInterruptPin = 1

# * Set up keypad matrix GPIO and interrupts *

def SetupKeypad(registerBaseAddress):
    SetupKeypadGPIO(registerBaseAddress)
    SetupKeypadInterrupt(registerBaseAddress)
    ClearKeypadInterrupt(registerBaseAddress)

def SetupKeypadGPIO(registerBaseAddress):
    UpperNibbleInputLowerNibbleOutput = 0xf0 # (GP4~7, Row0~3) = input, lower nibble (GP0~3, Column0~2, 3 = no coonect) = output
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, InputOutputDirection, PortA, UpperNibbleInputLowerNibbleOutput)
    WriteAllColumnsLow(registerBaseAddress)

def SetupKeypadInterrupt(registerBaseAddress):
    EnableInterruptOnChangeHighNibble(registerBaseAddress) # Enable interrupt on upper nibble (GP4~7)
    SetInterruptOnChangeDefaultHighNibble(registerBaseAddress) # Interrupt default values = all high (GP4~7 0b1111)
    SetInterruptOnChangeCompareDefaultHighNibble(registerBaseAddress) # select compare default value interrutpt 
    SetInterruptOutputOpenDrain(registerBaseAddress) # set interrupt output (INT) open drain

def EnableInterruptOnChangeHighNibble(registerBaseAddress): 
    EnableInterruptHighNibble = 0xf0
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, InterruptEnable, PortA, EnableInterruptHighNibble)

def SetInterruptOnChangeDefaultHighNibble(registerBaseAddress): 
    DefaultValueByte = 0xf0 
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, InterruptOnChangeDefaultValue, PortA, DefaultValueByte)

def SetInterruptOnChangeCompareDefaultHighNibble(registerBaseAddress): 
    InterruptOnChangeDefaultValueHighNibble = 0xf0 # GP4~7 change from default value will cause interrupt
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, CompareMode, PortA, InterruptOnChangeDefaultValueHighNibble)

def SetInterruptOutputPushPull(registerBaseAddress): # interrupt pin open drain, no auto add inc, no slew rate
    PushPull  = 0b00111010 # 0x32, seq/slew disabled, interrupt output drive drive (push pull) active High
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, PushPullOpenDrain, PortA, PushPull)

def SetInterruptOutputOpenDrain(registerBaseAddress): # interrupt pin open drain, no auto add inc, no slew rate
    OpenDrain = 0b00111000 # 0x34, seq/slew disabled, interrupt output open drain (don't care active High or Low)
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, PushPullOpenDrain, PortA, OpenDrain)

# * Clear and poll interrupts *

def ClearKeypadInterrupt(registerBaseAddress):
    WriteAllColumnsLow(registerBaseAddress)
    time.sleep(0.5)
    dummyRead = ReadInterruptCaptureHighNibble(registerBaseAddress) 

def ReadKeypadInterruptPin(interruptPin):
    interruptStatus = readInputPin(interruptPin)
    return interruptStatus

# * Write columns *

def WriteColumns(registerBaseAddress, columnDataNibble):
    columnDataByte = columnDataNibble | 0x00
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, OutputLatch, PortA, columnDataByte)

def WriteAllColumnsLow(registerBaseAddress):
    AllColumnsLowNibble = 0x0
    WriteColumns(registerBaseAddress, AllColumnsLowNibble)

def WriteColumn0Low(registerBaseAddress):
    Column0LowNibble = 0xe
    WriteColumns(registerBaseAddress, Column0LowNibble)

def WriteColumn1Low(registerBaseAddress):
    Column1LowNibble = 0xd
    WriteColumns(registerBaseAddress, Column1LowNibble)

def WriteColumn2Low(registerBaseAddress):
    Column2LowNibble = 0xb
    WriteColumns(registerBaseAddress, Column2LowNibble)

# * Read rows *

def GetRowDataByte(registerBaseAddress): 
    rowDataByte = ReadDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, PortStatus, PortA)
    return rowDataByte

def GetRowDataNibble(registerBaseAddress): 
    rowDataByte = ReadDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, PortStatus, PortA)
    rowDataNibble = rowDataByte >> 4
    return rowDataNibble

# * Get row number, column number, and key number *

def GetRowNumber(registerBaseAddress):
    rowDataByte = ReadDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, PortStatus, PortA)
    rowDataNibble = rowDataByte >> 4
    if rowDataNibble == 0b1110:
        rowNumber = 0
        return rowNumber
    elif rowDataNibble == 0b1101:
        rowNumber = 1
        return rowNumber
    elif rowDataNibble == 0b1011:
        rowNumber = 2
        return rowNumber
    elif rowDataNibble == 0b0111:
        rowNumber = 3
        return rowNumber
    else:
        rowNumber = 99  
return rowNumber

def GetColumnNumber(registerBaseAddress):
    RowsAllHigh = 0xf

    WriteColumn0Low(registerBaseAddress)
    rowDataNibble = ReadUpperNibble(registerBaseAddress, RegisterAddressOffsetArrayBank0, PortStatus, PortA)
    if rowDataNibble != RowsAllHigh:
        columnNumber = 0
        return columnNumber

    WriteColumn1Low(registerBaseAddress)
    rowDataNibble = ReadUpperNibble(registerBaseAddress, RegisterAddressOffsetArrayBank0, PortStatus, PortA)
    if rowDataNibble != RowsAllHigh:
        columnNumber = 1
        return columnNumber

    WriteColumn2Low(registerBaseAddress)
    rowDataNibble = ReadUpperNibble(registerBaseAddress, RegisterAddressOffsetArrayBank0, PortStatus, PortA)
    if rowDataNibble != RowsAllHigh:
        columnNumber = 2
        return columnNumber

def GetKeyNumber(rowNumber, columnNumber):
    # print "Row Number = ", rowNumber
    # print "Column Number = ", columnNumber
    keyNumber = (rowNumber * 3) + (columnNumber + 1) 
    return keyNumber

# * Get one key and a sequence of keys *

def GetKey(registerBaseAddress, pollType): 
    PollGpioRegister = 0
    PollKeypadInterruptPin = 1

    if (pollType == PollGpioRegister):
        # print "Polling GpioRegister"
        LoopUntilGpioPortHighNibbleChange(registerBaseAddress) 

    elif (pollType == PollKeypadInterruptPin):
        # print "Polling Interrupt Pin"
        LoopUntilKeypadInterruptPinLow(registerBaseAddress, KeypadInterruptPin)         

    rowNumber = GetRowNumber(registerBaseAddress)
    columnNumber = GetColumnNumber(registerBaseAddress)
    keyNumber = GetKeyNumber(rowNumber, columnNumber)
    return keyNumber

def GetKeyString(registerBaseAddress, pollType, count): 
    for i in range (count):        
        OneBeep() 
keyNumber = GetKey(registerBaseAddress, pollType)
        print "Key", i + 1, " = ", keyNumber

# * Loop until row data changes *

def LoopUntilGpioPortHighNibbleChange(registerBaseAddress): 
    WriteAllColumnsLow(registerBaseAddress)
    NoKeyPressedNibble = 0xf
    rowDataNibble = NoKeyPressedNibble 
    while (rowDataNibble == NoKeyPressedNibble):
        rowDataNibble = GetRowDataNibble(registerBaseAddress)
    time.sleep(0.05) # debouncing time 50mS

# * Loop until interrupt key low *

def LoopUntilKeypadInterruptPinLow(registerBaseAddress, interruptPin):
    ClearKeypadInterrupt(registerBaseAddress)
    interruptPinState = readInputPin(interruptPin)
    #print "interruptPinState = ", interruptPinState
    while (interruptPinState == True):
       interruptPinState = readInputPin(interruptPin) 
       #print "interruptPinState = ", interruptPinState
       #time.sleep(1)
    #print "interruptPinState = ", interruptPinState
    time.sleep(0.05) # debouncing time 50mS

# * Test keypad *

def TestKeypad(registerBaseAddress, pollType, count):
    SetupKeypad(registerBaseAddress)
    if (pollType == PollKeypadInterruptPin):
        SetupKeypadInterrupt(registerBaseAddress)
        ClearKeypadInterrupt(registerBaseAddress)
    print "*** Start testing keypad. ***"  
    print "Press keypad ", count, "times."
    GetKeyString(registerBaseAddress, pollType, count)
    ClearKeypadInterrupt(registerBaseAddress)
    print "*** Stop testing keypad. ***\n"

def TestPollingKeypad():
    TestKeypad(KeypadRegisterBaseAddress, PollGpioRegister, count = 4)

def TestInterruptKeypad():
    TestKeypad(KeypadRegisterBaseAddress, PollKeypadInterruptPin, count = 4)


# * LCD1602 ******************************************************************* 

LcdRegisterBaseAddress = MCP23008BaseAddress3 # 0x26 

# * LCD1602A-1 16-pin connector (MCP23008 GPIO 6-pin connector) Pin numbering *

# Pin 04 (Pin 1) RegisterSelect
# Pin 06 (Pin 2) WriteEnable  
# Pin 11 (Pin 3) DataBit4 = 2
# Pin 12 (Pin 4) DataBit5 = 3
# Pin 13 (Pin 5) DataBit6 = 4
# Pin 14 (Pin 6) DataBit7 = 5

# LCD1602 software initialization procedure

# Part 1 - Pseudo 8 bit instructions to config 4 bit instruction mode (0x30, 0x30, 0x30, 0x20)

# 1. Power on, wait 20mS (> 15mS)
# 2. Write 0x3, wait 5mS (> 4.1mS) # set 8 bit interface
# 3. Write 0x3, wait 1mS (> 100uS) # set 8 bit interface
# 4. Write 0x3, wait 1mS (> 37uS)  # set 8 bit interface
# 5. Write 0x2, wait 1mS (> 37uS)  # set 4 bit interface

# Part 2- 4 bit instructions to config display characteristics (0x28, 0x08, 0x01, 0x06, 0x02)

# 6. Write 0x2, wait 1mS (> 37uS) 0x8 wait 1mS (> 37uS) (2 lines, 5x8 dot)
# 7. Write 0x0, wait 1mS (> 37uS) 0x8 wait 1mS (> 37uS) (cursor on, no blinking, blank screen)
# 8. Write 0x0, wait 1mS (> 37uS) 0x1 wait 2mS (> 1.52mS)(clear display)
# 9. Write 0x0, wait 1mS (> 37uS) 0xe (DisplayOnCursorOnCursorBlinkOff)
# a. Write 0x0, wait 1mS (> 37uS) 0x2 wait 2mS (cursor home)

# * LCD1602A-1 16-pin connector pin numbering *

RegisterSelect = 0 # 0 = instruction register, 1 = data register
WriteEnable = 1 # 1 = enable, 0 = disable 
DataBit4 = 2
DataBit5 = 3
DataBit6 = 4
DataBit7 = 5

# * Constant data bytes *

AllZeroDataByte = 0x00
AllOneDataByte = 0xff

# * Write Enable/Disable, Select Data/Instruction masks *

EnableWriteMask  = 0x02 # 0b 0000 0010
DisableWriteMask = 0xfd # 0b 1111 1101

SelectDataRegisterMask        = 0x01 # 0b 0000 0001
SelectInstructionRegisterMask = 0xfe # 0b 1111 1110

# Register selection constant *

InstructionRegister = 0
DataRegister = 1

# * LCD1602A-1 control instructions *

# * Instruction codes *

EightBitInstructionMode = 0x3
FourBitInstructionMode  = 0x2

TwoLineFiveTimesEightDot1 = 0x2
TwoLineFiveTimesEightDot2 = 0x8

DisplayOnCursorOnCursorBlinkOff1 = 0x0
DisplayOnCursorOnCursorBlinkOff2 = 0xe

ClearDisplay1 = 0x0
ClearDisplay2 = 0x1

CursorIncrementDisplayNoShift1 = 0x0
CursorIncrementDisplayNoShift2 = 0x6

CursorHome1 = 0x0
CursorHome2 = 0x2

# * Instruction timing *

PowerOnResetDelay      = 0.05    # 50mS
VeryLongOperationDelay = 0.005   # 5mS
LongOperationDelay     = 0.002   # 2mS
ShortOperationDelay    = 0.00005 # 50uS
WritePulseLength       = 0.00005 # 50uS

# * RPi/MCP23008 Python functions *

def LcdGpioSetup(registerBaseAddress):
    SetupMCP23008PortAllOutput(registerBaseAddress)

def LcdConfiguration(registerBaseAddress):
    dataControlByte = AllZeroDataByte
    # PrintEightBitPattern("dataControlByte01 = ", dataControlByte)
    LcdDisableWrite(registerBaseAddress, dataControlByte)
    time.sleep(PowerOnResetDelay)

    dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, EightBitInstructionMode, InstructionRegister, VeryLongOperationDelay) 
    # PrintEightBitPattern("dataControlByte02 = ", dataControlByte)
    dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, EightBitInstructionMode, InstructionRegister, LongOperationDelay) 
    # PrintEightBitPattern("dataControlByte03 = ", dataControlByte)
    dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, EightBitInstructionMode, InstructionRegister, LongOperationDelay) 
    # PrintEightBitPattern("dataControlByte04 = ", dataControlByte)
    dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, FourBitInstructionMode, InstructionRegister, LongOperationDelay) 
    # PrintEightBitPattern("dataControlByte05 = ", dataControlByte)

    dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, TwoLineFiveTimesEightDot1, InstructionRegister, LongOperationDelay) 
    # PrintEightBitPattern("dataControlByte06 = ", dataControlByte)
    dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, TwoLineFiveTimesEightDot2, InstructionRegister, LongOperationDelay)
    # PrintEightBitPattern("dataControlByte07 = ", dataControlByte)

    dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, DisplayOnCursorOnCursorBlinkOff1, InstructionRegister, LongOperationDelay) 
    # PrintEightBitPattern("dataControlByte08 = ", dataControlByte)
    dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, DisplayOnCursorOnCursorBlinkOff2, InstructionRegister, LongOperationDelay)
    # PrintEightBitPattern("dataControlByte09 = ", dataControlByte)

    dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, ClearDisplay1, InstructionRegister, LongOperationDelay) 
    # PrintEightBitPattern("dataControlByte10 = ", dataControlByte)
    dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, ClearDisplay2, InstructionRegister, LongOperationDelay)
    # PrintEightBitPattern("dataControlByte11 = ", dataControlByte)

    dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, CursorIncrementDisplayNoShift1, InstructionRegister, LongOperationDelay) 
    # PrintEightBitPattern("dataControlByte12 = ", dataControlByte)
    dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, CursorIncrementDisplayNoShift2, InstructionRegister, LongOperationDelay)
    # PrintEightBitPattern("dataControlByte13 = ", dataControlByte)

    dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, CursorHome1, InstructionRegister, LongOperationDelay) 
    # PrintEightBitPattern("dataControlByte14 = ", dataControlByte)
    dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, CursorHome2, InstructionRegister, LongOperationDelay)
    # PrintEightBitPattern("dataControlByte15 = ", dataControlByte)

    return dataControlByte

def LcdSelectDataRegister(registerBaseAddress, dataByte):
    dataByte = dataByte | SelectDataRegisterMask
    LcdWriteDataByte(registerBaseAddress, dataByte)  
    return dataByte

def LcdSelectInstructionRegister(registerBaseAddress, dataByte):
    dataByte = dataByte & SelectInstructionRegisterMask
    LcdWriteDataByte(registerBaseAddress, dataByte)
    return dataByte

def LcdEnableWrite(registerBaseAddress, dataByte):
    dataByte = dataByte | EnableWriteMask
    LcdWriteDataByte(registerBaseAddress, dataByte)
    return dataByte

def LcdDisableWrite(registerBaseAddress, dataByte):
    dataByte = dataByte & DisableWriteMask
    LcdWriteDataByte(registerBaseAddress, dataByte)
    return dataByte

def LcdWritePulse(registerBaseAddress, dataByte):
    LcdEnableWrite(registerBaseAddress, dataByte)
    time.sleep(WritePulseLength)
    LcdDisableWrite(registerBaseAddress, dataByte)
    return dataByte

def LcdWriteDataByte(registerBaseAddress, dataByte):
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, OutputLatch, PortA, dataByte)
    return dataByte

def LcdWriteDataNibble(registerBaseAddress, dataByte, dataNibble, registerType, operationDelay):
    dataNibble = dataNibble << 2
    dataByte = dataByte & 0b11000011
    dataByte = dataByte | dataNibble
    if (registerType == InstructionRegister):
       dataByte = LcdSelectInstructionRegister(registerBaseAddress, dataByte)
    elif (registerType == DataRegister):
       dataByte = LcdSelectDataRegister(registerBaseAddress, dataByte)
    LcdDisableWrite(registerBaseAddress, dataByte)
    dataByte = LcdWriteDataByte(registerBaseAddress, dataByte)
    LcdWritePulse(registerBaseAddress, dataByte)
    time.sleep(operationDelay)
    return dataByte

def LcdWriteCharFourBitMode(registerBaseAddress, dataControlByte, asciiChar, registerType):
    charUpperNibble = ord(asciiChar) >> 4
    charLowerNibble = ord(asciiChar) & 0x0f
    LcdWriteCharTwoNibbles(registerBaseAddress, dataControlByte, charUpperNibble, charLowerNibble, registerType)
    return dataControlByte

def LcdWriteDataByteFourBitMode(registerBaseAddress, dataControlByte, dataByte, registerType):
    upperNibble = dataByte >> 4
    lowerNibble = dataByte & 0x0f
    LcdWriteCharTwoNibbles(registerBaseAddress, dataControlByte, upperNibble, lowerNibble, registerType)
    return dataControlByte

def LcdWriteCharTwoNibbles(registerBaseAddress, dataControlByte, upperNibble, lowerNibble, registerType):
    dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, upperNibble, registerType, ShortOperationDelay) 
    # PrintEightBitPattern("dataControlByte01 = ", dataControlByte)
    dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, lowerNibble, registerType, ShortOperationDelay)
    # PrintEightBitPattern("dataControlByte02 = ", dataControlByte)
    return dataControlByte

def LcdWriteCharString(registerBaseAddress, dataControlByte, string):
    for asciiChar in (string):
        LcdWriteCharFourBitMode(registerBaseAddress, dataControlByte, asciiChar, DataRegister)
    return dataControlByte

def LcdMoveCursor(registerBaseAddress, dataControlByte, rowNumber, columnNumber):
    if (rowNumber == 1):
       cursorByte = 0x80 | (0x00 + (columnNumber - 1)) # command = 0x80, row 1 DDRAM start address = 0x10
    elif (rowNumber == 2):
       cursorByte = 0x80 | (0x40 + (columnNumber - 1)) # row 2 DDRAM start address = 0x40
    LcdWriteDataByteFourBitMode(registerBaseAddress, dataControlByte, cursorByte, InstructionRegister)

    # charUpperNibble = cursorByte >> 4
    # charLowerNibble = cursorByte & 0x0f
    # dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, charUpperNibble, InstructionRegister, ShortOperationDelay)
    # dataControlByte = LcdWriteDataNibble(registerBaseAddress, dataControlByte, charLowerNibble, InstructionRegister, ShortOperationDelay)
    return dataControlByte

# * Test LCD1602 functions *

def TestLcd(registerBaseAddress):
    LcdGpioSetup(registerBaseAddress)
    dataControlByte = LcdConfiguration(registerBaseAddress)
    dataControlByte = LcdMoveCursor(registerBaseAddress, dataControlByte, 1, 2)
    dataControlByte = LcdWriteCharString(registerBaseAddress, dataControlByte, "Raspberry Pi")
    dataControlByte = LcdMoveCursor(registerBaseAddress, dataControlByte, 2, 1)
    dataControlByte = LcdWriteCharString(registerBaseAddress, dataControlByte, "2013-01-25 v1141")

# 8. Unipolar Stepping Motor 28BYJ48/NPM-PF35/PX245 ***************************

# Unipolar Stepping Motor Switching Sequence 
# 1. Wave sequence = 1 - 3 - 2 - 4 (A-, B-, A+, B+)
# 2. Full step sequence = 13 - 14 - 24 - 23 (A-B-, A-B+, A+B+, A+B-)
# 3. Half step sequence  = 13 - 1 - 14 - 4 - 24 - 2 - 23 - 3 
# 4. One step swing = 1 - 3 - 1 - 3 (A-, B-, A-, B-)
# Winding        A-(1)    A+(2)    B-(3)   B+(4)    COM
# NPM PF35       Black    Yellow   Brown   Orange   Red
# 28BYJ48        Blue     Pink     Yellow  Orange   Red  
# PX245          Black    Green    Blue    Red      Yelow/White

# * Convert decimal pin number to hex *
def convert1PinToHex(p): # convert 1 of 8 high pin to hex
    hexString = 0x01
    for count in range(p-1):
    hexString = hexString << 1
    return hexString
def convert2PinToHex(p1, p2):  # convert 2 of 8 high pins to hex
    return (convert1PinToHex(p1) | convert1PinToHex(p2))

def convert2PinToHighNibble(p1, p2):  # convert 2 of 8 high pins to high nibble
    lowNibble = convert1PinToHex(p1) | convert1PinToHex(p2)
    highNibble = lowNibble << 4
    return highNibble

# * Move unipolar stepping motor *

def WriteMotorWindingWaveSequence1324(RegisterBaseAddress, NibbleType, StepCount, StepTime): # move motor using 13-24 sequence  
    # Set port all output
    WriteDataByte(MCP23008BaseAddress1, RegisterAddressOffsetArrayBank0, InputOutputDirection, PortA, AllOutputByte)

    if NibbleType == LowNibble:
hexString1 =  convert2PinToHex(1, 3)
  hexString2 =  convert2PinToHex(2, 4)
    else:
hexString1 = convert2PinToHighNibble(1, 3)
hexString2 = convert2PinToHighNibble(2, 4)
    for i in range(StepCount):
        WriteDataByte(MCP23008BaseAddress1, RegisterAddressOffsetArrayBank0, OutputLatch, PortA, hexString1) 
    time.sleep(StepTime)
        WriteDataByte(MCP23008BaseAddress1, RegisterAddressOffsetArrayBank0, OutputLatch, PortA, hexString2) 
        time.sleep(StepTime)

def WriteMotorWindingFullStepSequence13232414(RegisterBaseAddress, NibbleType, StepCount, StepTime): #move motor using 13-23-24-14 sequence 
    # Set port all output
    WriteDataByte(MCP23008BaseAddress1, RegisterAddressOffsetArrayBank0, InputOutputDirection, PortA, AllOutputByte)

    if NibbleType == LowNibble:
    motorWindingActivationPatternArray = (0x05, 0x06, 0x0a, 0x09)
    else:
motorWindingActivationPatternArray = (0x50, 0x60, 0xa0, 0x90)
    for i in range(StepCount):
for pattern in motorWindingActivationPatternArray:
            WriteDataByte(MCP23008BaseAddress1, RegisterAddressOffsetArrayBank0, OutputLatch, PortA, pattern) 
   time.sleep(StepTime)

def TestConvert1PinToHex(): # test convert 1 high pin to hex
    print "*** Testing 1 pin number decimal 0 ~ 7 converted to hexdecimal 0x01 ~ 0x80"
    for d in range(8):
    print hex(convert1PinToHex(d))

def TestConvert2PinToHex(p1, p2): # test convert 2 high pins to hex
    print "*** Testing 2 pin numbers decimal 0 ~ 7 converted to hexdecimal"
    print "Pin 1 = ", p1, "Pin 2 = ", p2
    print "Hex = ", hex(convert2PinToHex(p1, p2))

def TestConvert2PinToHighNibble(p1, p2): # test convert 2 of 8 high pins to high nibble
    print "*** Testing 2 pin numbers decimal 0 ~ 7 converted to high nibble"
    print "Pin 1 = ", p1, "Pin 2 = ", p2
    print "HighNibble = ", hex(convert2PinToHighNibble(p1, p2))

def MoveTwoMotors(RegisterBaseAddress):  
OneBeep()
WriteMotorWindingWaveSequence1324(MCP23008BaseAddress1, LowNibble, TwentyTimes, FiftyMilliSeconds)
OneBeep()
WriteMotorWindingWaveSequence1324(MCP23008BaseAddress1, HighNibble, TwentyTimes, FiftyMilliSeconds)
OneBeep()
WriteMotorWindingFullStepSequence13232414(MCP23008BaseAddress1, LowNibble, TwentyTimes, OneHundredMilliSeconds)
OneBeep()
WriteMotorWindingFullStepSequence13232414(MCP23008BaseAddress1, HighNibble, TwentyTimes, OneHundredMilliSeconds)

def TestMotor():
    MotorRegisterBaseAddress = MCP23008BaseAddress1
    MoveTwoMotors(MotorRegisterBaseAddress)

# * Demultiplexer *************************************************************

DemuxRegisterBaseAddress = KeypadRegisterBaseAddress

def DemuxGpioSetup(registerBaseAddress):
    UpperNibbleInputLowerNibbleOutput = 0xf0 # Input (GP4~7, Row0~3), Output (GP0~3, Column0~2, 3 reserved)
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, InputOutputDirection, PortA, UpperNibbleInputLowerNibbleOutput)
    InitialControlDateByte = 0x00
    return InitialControlDateByte

def DemuxAddressLatch(controlDataByte, latchAction):
    DemuxAddressLatchMask = 0b00001000
    Enable = 1
    Disable = 0
    if (latchAction == Enable):
        controlDataByte = controlDataByte | DemuxAddressLatchMask
    elif (latchAction == Disable):
       controlDataByte = controlDataByte & ~(DemuxAddressLatchMask)
    return controlDataByte

def SetDemuxChannel(registerBaseAddress, controlDataByte, addressNibble):
    Enable = 1
    Disable = 0
    controlDataByte = controlDataByte & 0b11110000
    addressNibble = addressNibble & 0b00000111
    controlDataByte = controlDataByte | addressNibble
    controlDataByte = DemuxAddressLatch(controlDataByte, Disable)
    PrintEightBitPattern("demuxDataByte = ", controlDataByte)
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, OutputLatch, PortA, controlDataByte)
    controlDataByte = DemuxAddressLatch(controlDataByte, Enable)
    PrintEightBitPattern("demuxDataByte = ", controlDataByte)
    WriteDataByte(registerBaseAddress, RegisterAddressOffsetArrayBank0, OutputLatch, PortA, controlDataByte)
    return controlDataByte

def TestDemux(demuxRegisterBaseAddress, channelNumber):  
    controlDataByte = DemuxGpioSetup(demuxRegisterBaseAddress) 
    controlDataByte = SetDemuxChannel(demuxRegisterBaseAddress, controlDataByte, channelNumber)

def TestDemuxLcd(demuxRegisterBaseAddress, lcdRegisterBaseAddress, channelNumber1, channelNumber2):
    Row1 = 1
    Row2 = 2
    Row3 = 3
    Row4 = 4
    Column1 = 1

    # Setup one MCP23008 for Demultiplexor, another MCP23008 for LCD1602/LCD2004
    controlDataByte = DemuxGpioSetup(demuxRegisterBaseAddress) 
    LcdGpioSetup(lcdRegisterBaseAddress)

    # Select demux channelNumber1
    controlDataByte = SetDemuxChannel(demuxRegisterBaseAddress, controlDataByte, channelNumber1)

    # Display two lines in the LCD at this channel
    dataControlByte = LcdConfiguration(lcdRegisterBaseAddress)
    dataControlByte = LcdMoveCursor(lcdRegisterBaseAddress, dataControlByte, Row1, Column1)
    dataControlByte = LcdWriteCharString(lcdRegisterBaseAddress, dataControlByte, "Channel 1 01")
    dataControlByte = LcdMoveCursor(lcdRegisterBaseAddress, dataControlByte, Row2, Column1)
    dataControlByte = LcdWriteCharString(lcdRegisterBaseAddress, dataControlByte, "2013-01-28 v201")

    time.sleep(2)

    # Select demux channelNumber2
    controlDataByte = SetDemuxChannel(demuxRegisterBaseAddress, controlDataByte, channelNumber2)

    # Display two lines in the LCD at this channel
    dataControlByte = LcdConfiguration(lcdRegisterBaseAddress)
    dataControlByte = LcdMoveCursor(lcdRegisterBaseAddress, dataControlByte, Row1, Column1)
    dataControlByte = LcdWriteCharString(lcdRegisterBaseAddress, dataControlByte, "Channel 2 01")
    dataControlByte = LcdMoveCursor(lcdRegisterBaseAddress, dataControlByte, Row2, Column1)
    dataControlByte = LcdWriteCharString(lcdRegisterBaseAddress, dataControlByte, "2013-01-30 v204")

    time.sleep(2)

# 12. Old test functions *****************************************************

# * Old tests *

# RPi System A Tests *

# TestBuzzer() # beep buzzer 4 times
# TestLED() # blink LED 4 tmes
# TestButtonEchoBuzzer() # echo buton with buzzer 4 times
# TestButtonEchoLED() # echo button with LED 4 times
# TestToggleMCP23017GP() # toggle MCP23017 #1 output ports (connected to only 1 LED)
# TestToggleMCP23008GP() # toggle MCP23008 #1 output port (connected to stepping motors)
# TestMotor() # move two stepping motors
# TestPollingKeypad() # read 4 keys by polling IO Expander GPIO port of rows (MCP23008 #2)
# TestInterruptKeypad() # read 4 keys by polling IO Expander INT pin # !!! not tested !!!
# TestLcd(LcdRegisterBaseAddress) 
# TestDemux(DemuxRegisterBaseAddress, 4)  
# TestDemuxLcd(DemuxRegisterBaseAddress, LcdRegisterBaseAddress, channelNumber1 = 0, channelNumber2 = 1)

# RPi System B Tests *

# TestBuzzer() # beep buzzer 4 times
# TestLED() # blink LED 4 tmes
# TestButtonEchoBuzzer() # echo buton with buzzer 4 times
# TestButtonEchoLED() # echo button with LED 4 times

# TestToggleMCP23017SystemB1() # toggle MCP23017 System B1
# TestReadMCP23017SystemB1()

# 13. Main program ************************************************************

StartProgram()

TestToggleMCP23017SystemB1(count = 4)
TestReadMCP23017SystemB1(count = 4)
TestKeypad017(checkPressingKeyMode = NoPollJustGetKeyEverySecond, keyCount = 4) 
TestKeypad017(checkPressingKeyMode = PollRowStatusNibble, keyCount = 4)

# TestKeypad017(checkPressingKeyMode = PollInterruptCaptureNibble, keyCount = 4)

StopProgram()

# *****************************************************************************
# End of Program
# *****************************************************************************

pi@raspberrypi ~/python_programs/test_basic $ sudo python fpl301.py

*** Start Program - FPL v3.00 TL Fong 2013feb04 *******************************

Data byte read =  11111111
Data byte read =  11111111
Data byte read =  11111111
Data byte read =  11111101
Read key every second
Row pattern =  1111
('Row number = ', 4)
Key 1  =  15
Read key every second
Row pattern =  1111
('Row number = ', 4)
Key 2  =  14
Read key every second
Row pattern =  1101
('Row number = ', 1)
Key 3  =  5
Read key every second
Row pattern =  1111
('Row number = ', 4)
Key 4  =  15
Polling Gpio
Row pattern =  1101
('Row number = ', 1)
Key 1  =  4
Polling Gpio
Row pattern =  1110
('Row number = ', 0)
Key 2  =  3
Polling Gpio
Row pattern =  1101
('Row number = ', 1)
Key 3  =  6
Polling Gpio
Row pattern =  1101
('Row number = ', 1)
Key 4  =  5

*** Stop Program **************************************************************