Testing MCP23S17

Now I am reading the ftiox module to refresh my memory on how did I test MCP23S14.

.END

# *** Mcp23s17 ***

# ftiox.TestMcp23s17BlinkLed(spiChannelNumber = 0, spiChipEnableNumber = 0, spiChipSubAddress = 0)

# ftiox.py v1.3 tlfong01 2013may29

# *****************************************************************************
# Module - ftiox.py
# Description - IO expander functions using I2C MCP230x, SPI MCP23sxx
# *****************************************************************************

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

import time
import spidev
import ftspi

# *****************************************************************************
# Constants and variables
# *****************************************************************************

PortA = 0
PortB = 1

InputOutputDirectionIndex = 0
InputPolarityIndex = 1
InterruptEnableIndex = 2
DefaultValueIndex = 3  
CompareModeIndex = 4
BankInterruptPinModeIndex = 5
PullUpIndex = 6
InterruptFlagIndex = 7
InterruptCaptureIndex = 8
PortStatusIndex = 9
OutputLatchIndex = 10

All8pinOutput = 0x00
All8pinInput = 0xff
All8bitOne = 0xff
All8bitZero = 0x00
All8bitPullUp = 0xff

Upper8bitOneLower8bitZero  = 0xff00
Upper8bitZeroLower8bitOne  = 0x00ff
Upper4bitOneLower4bitZero  = 0xf0
Upper4bitZeroLower4bitOne  = 0x0f

Upper8pinInputLower8pinOutput  = 0xff00
Upper8pinOutputLower8pinInput  = 0x00ff
Upper4pinInputLower4pinOutput  = 0xf0
Upper4pinOutputLower4pinInput  = 0x0f

DataByte0x55 = 0x55
DataByte0xaa = 0xaa
DataByte0x00 = 0x00
DataByte0xff = 0xff

RegisterAddressArrayMcp23s17 = [0x00, 0x02, 0x04, 0x06, 0x08, 0x0a, 0x0c, 0x0e, 0x10, 0x12, 0x14,        
                                0x01, 0x03, 0x05, 0x07, 0x09, 0x0b, 0x1d, 0x0f, 0x11, 0x13, 0x15]

Mcp23s17WriteCommand = 0b01000000

# *****************************************************************************
# MCP23s17 Test functions
# *****************************************************************************

# *****************************************************************************
# Function - TestMcp23s17BlinkLed
# Description - Blink the 16 LEDs conntected to MCP23s17 Port A and Port B
# Sample call - 
# TestMcp23s17BlinkLed(spiChannelNumber = 0, spiChipEnableNumber1bit = 0, spiChipSubAddress = 0)
# *****************************************************************************

def TestMcp23s17BlinkLed(spiChannelNumber, spiChipEnableNumber, spiChipSubAddress):

    spiChannel = spidev.SpiDev() 
    spiChannel.open(spiChannelNumber, spiChipEnableNumber)  

    SetupMcp23s17Ports(spiChannel, spiChipSubAddress, portAsetupByte = All8pinOutput, portBsetupByte = All8pinOutput)

    # *** Write Port A and Port B with constants ***

    DisableHC137ControlByte = 0x20 # b0010 0000  = CS1 Low, CS2 High, All Yn High
    EnableHC137ControlByte  = 0x10 # b0001 0000  = CS1 High, CS2 Low, 1 of 8 Yn low

    # WriteDataByteMcp23s17OutputLatchPortA(spiChannel, spiChipSubAddress, EnableHC137ControlByte)
    # WriteDataByteMcp23s17OutputLatchPortB(spiChannel, spiChipSubAddress, EnableHC137ControlByte)
    # WriteDataByteMcp23s17OutputLatchPortA(spiChannel, spiChipSubAddress, DisableHC137ControlByte)
    # WriteDataByteMcp23s17OutputLatchPortB(spiChannel, spiChipSubAddress, DisableHC137ControlByte)
    # while True:
    #    pass

    print "Now blinking LEDs, ... "

    # *** Blink Port A and Port B LEDs *** 

    for i in range (10):
        # *** Write 0x55 to Port A and 0xaa to Port B ***
        WriteDataByteMcp23s17(spiChannel, spiChipSubAddress, RegisterAddressArrayMcp23s17, OutputLatchIndex, PortA, DataByte0x55)
        WriteDataByteMcp23s17(spiChannel, spiChipSubAddress, RegisterAddressArrayMcp23s17, OutputLatchIndex, PortB, DataByte0xaa)

        time.sleep(0.5)
        # *** Write 0xaa to Port A and 0x55 to Port B ***
        WriteDataByteMcp23s17(spiChannel, spiChipSubAddress, RegisterAddressArrayMcp23s17, OutputLatchIndex, PortA, DataByte0xaa)
        WriteDataByteMcp23s17(spiChannel, spiChipSubAddress, RegisterAddressArrayMcp23s17, OutputLatchIndex, PortB, DataByte0x55)
        time.sleep(0.5)

    for i in range (10):
        # *** Write 0x00 to Port A and 0x00 to Port B ***
        WriteDataByteMcp23s17(spiChannel, spiChipSubAddress, RegisterAddressArrayMcp23s17, OutputLatchIndex, PortA, DataByte0x00)
        WriteDataByteMcp23s17(spiChannel, spiChipSubAddress, RegisterAddressArrayMcp23s17, OutputLatchIndex, PortB, DataByte0x00)
time.sleep(0.5)

# *** Write 0xff to Port A and 0xff to Port B ***
        WriteDataByteMcp23s17(spiChannel, spiChipSubAddress, RegisterAddressArrayMcp23s17, OutputLatchIndex, PortA, DataByte0xff)
        WriteDataByteMcp23s17(spiChannel, spiChipSubAddress, RegisterAddressArrayMcp23s17, OutputLatchIndex, PortB, DataByte0xff)
time.sleep(0.5)

# *****************************************************************************
# Basic MCP23s17 functions
# *****************************************************************************

def SetupMcp23s17Ports(spiChannel, spiChipSubAddress, portAsetupByte, portBsetupByte):
    WriteDataByteMcp23s17(spiChannel, spiChipSubAddress, RegisterAddressArrayMcp23s17, InputOutputDirectionIndex, PortA, portAsetupByte)
    WriteDataByteMcp23s17(spiChannel, spiChipSubAddress, RegisterAddressArrayMcp23s17, InputOutputDirectionIndex, PortB, portBsetupByte)

def WriteDataByteMcp23s17OutputLatchPortA(spiChannel, spiChipSubAddress, dataByte):
    mcp23s17WriteCommand = Mcp23s17WriteCommand | (spiChipSubAddress << 1)
    mcp23s17RegisterAddress = GetRegisterAddress(RegisterAddressArrayMcp23s17, OutputLatchIndex, PortA)
    spiWriteList = [mcp23s17WriteCommand, mcp23s17RegisterAddress, dataByte]
    ftspi.SpiWrite(spiChannel, spiWriteList)

def WriteDataByteMcp23s17OutputLatchPortB(spiChannel, spiChipSubAddress, dataByte):
    mcp23s17WriteCommand = Mcp23s17WriteCommand | (spiChipSubAddress << 1)
    mcp23s17RegisterAddress = GetRegisterAddress(RegisterAddressArrayMcp23s17, OutputLatchIndex, PortB)
    spiWriteList = [mcp23s17WriteCommand, mcp23s17RegisterAddress, dataByte]
    ftspi.SpiWrite(spiChannel, spiWriteList)

def WriteDataByteMcp23s17(spiChannel, spiChipSubAddress, registerAddressArray, registerIndex, portType, dataByte):
    mcp23s17WriteCommand = Mcp23s17WriteCommand | (spiChipSubAddress << 1)
    mcp23s17RegisterAddress = GetRegisterAddress(registerAddressArray, registerIndex, portType)
    mcp23s17WriteDataByte = dataByte

    # PrintEightBitPattern("mcp23s17WriteCommand    = ", mcp23s17WriteCommand)
    # PrintEightBitPattern("mcp23s17RegisterAddress = ", mcp23s17RegisterAddress) 
    # PrintEightBitPattern("mcp23s17WriteDataByte   = ", mcp23s17WriteDataByte)

    spiWriteList = [mcp23s17WriteCommand, mcp23s17RegisterAddress, mcp23s17WriteDataByte]
    ftspi.SpiWrite(spiChannel, spiWriteList)

def GetRegisterAddress(registerAddressArray, registerIndex, portType):
    if (portType == PortA):
       registerAddress = registerAddressArray[registerIndex]
    if (portType == PortB):
       registerAddress = registerAddressArray[registerIndex + 11]
    return registerAddress

# .END