Wednesday, January 09, 2013
MCP23008 IO Expander - Interrupt control
Now I am cleaning up again. This time I did the following.
1. Move the loop invariant things out of the loops.
2. Split long and messy statement into functions.
The most critical function GetKey is looping for a key.
def GetKey(registerBaseAddress):
LoopUntilRowDataByteChange(registerBaseAddress)
rowDataByte = GetRowDataByte(registerBaseAddress)
rowNumber = GetRowNumber(rowDataByte)
columnNumber = GetColumnNumber(registerBaseAddress, rowDataByte)
keyNumber = GetKeyNumber(rowNumber, columnNumber)
return keyNumber
.END
*** Decimal Keypad Test v2.0 TL Fong 2013jan08 ***
Press keypad 4 times.
Key pressed = 01
Key pressed = 04
Key pressed = 07
Key pressed = 10
End of keypad test.
Interrupt flag nibble = 1111
Interrupt flag nibble = 1111
Interrupt flag nibble = 1110
Interrupt flag nibble = 1101
Interrupt flag nibble = 1011
Interrupt flag nibble = 0111
# *****************************************************************************
# *** tiox30.py ***
# Program - Test MCP23008 and MCP23017
# Version - 3.0
# Date - 2012nov30
# Update - 2013jan08
# Author - tlfong01
# File - tiox30_2013jan08.py
# Blog - http://tlfong01.blogspot.hk/
# Purpose - test basics of Raspberry Pi GPIO
# License - GNU GPLv3
# Hardware - Raspberry Pi Model B Revsion 2.0 [2012oct/nov/dec]
# Software - Raspbian Wheezy (2012sep15), Python 2.7.3
# GPIO 0.4.1a http://pypi.python.org/pypi/RPi.GPIO/0.4.1a
# Wiring - RPi Board 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
# *****************************************************************************
# *** Import Python modules ***
import smbus
import sys
import RPi.GPIO as GPIO
from time import sleep
import select # interrupt module
# *****************************************************************************
# * GPIO naming and setting up *
# * RPi.GPIO setting *
GPIO.setmode(GPIO.BOARD) # Use RPi GPIO numbering, Not BCM numbering
GPIO.setwarnings(False) # Disable linux's "pin already in use warning"
# * P1 pins numbering *
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 Interrupt
RPiTxD = 8 # Orange (P1-08) UART TxD
RPiRxD = 10 # Yellow (P1-10) UART RxD
# * IO device pins assignment *
LEDpin = RPiGPIOgen1
BuzzerPin = RPiGPIOgen4
ButtonPin = RPiGPIOgen5
InterruptPin = RPiGPIOgen6
TxDpin = RPiTxD
RxDpin = RPiRxD
# * IO pins list *
OutputPinList = [LEDpin, BuzzerPin, TxDpin]
InputPinWithNoPullUpList = [ButtonPin, RxDpin]
InputPinWithPullUpList = [InterruptPin]
# *****************************************************************************
# * 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
TenthSecond = 0.1
QuarterSecond = 0.25
HalfSecond = 0.5
OneSecond = 1
OneAndHalfSeconds = 1.5
TwoSeconds = 2
OnTime = TenthSecond
OffTime = QuarterSecond
ButtonDebouncingTime = QuarterSecond
TestTime = FiftyMilliSeconds
# * 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
# *****************************************************************************
# * GPIO functions *
# Note: 5V0 max = 50 mA, 3V3 max = 300 mA, per GPIO pin max = 17mA source, 12mA sink
# * 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 and echo functions *
def pulsePin(oPin, onTime, offTime): # blink LED or beep buzzer
writeOutputPin(oPin, On)
sleep(onTime)
writeOutputPin(oPin, Off)
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)
sleep(toggleTime)
writeOutputPin(oPin, Off)
sleep(toggleTime)
# * Test Buzzer, LED, Button functions *
def TestBuzzer(): # beep 4 times
SetupGPIO()
for i in range (FourTimes):
pulsePin(BuzzerPin, OnTime, OffTime)
def TestLED(): # blink 8 times
SetupGPIO()
for i in range (EightTimes):
pulsePin(LEDpin, OnTime, OffTime)
def TestButtonEchoBuzzer(): #
SetupGPIO()
for i in range (TenTimes):
echoPin(ButtonPin, BuzzerPin)
def TestButtonEchoLED(): #
SetupGPIO()
for i in range (TenTimes):
echoPin(ButtonPin, LEDpin)
def TestToggleTxDpin():
while True:
togglePin(TxDpin, TwoSeconds)
# 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
sleep(1)
continue
GPIO.set_low_event(InterruptPin, enable = False) # disable detection
print "End of test, or interrupt detected"
# *****************************************************************************
# * Beep functions *
def Beep(count):
for i in range(count):
pulsePin(BuzzerPin, OnTime, OffTime)
def StartBeep():
Beep(TwoTimes)
sleep(1)
def EndBeep():
Beep(FourTimes)
def OneBeep():
Beep(1)
def FourBeeps():
Beep(4)
# *****************************************************************************
# * MCP23008 / MCP23017 *
# * Bash script using i2cTools's i2cset command to toggle GPIO pins *
#!/bin/bash
# i2cset -y 1 0x20 0x00 0x00
# count=0
# while [ $count -lt 10 ];
# do
# i2cset -y 1 0x20 0x0a 0x00
# sleep 0.5
# i2cset -y 1 0x20 0x0a 0xff
# sleep 0.5
# let count++
# done
# To run i2c-X commands in user mode: sudo chmod 666 /dev/i2c-X
# sudo chmod 666 /dev/i2c-1
# To detect I2C device base addresses
# sudo i2cdetect -y 1
# * Setup SMBus *
I2C_BUS_NUMBER = 1 # P1-03 = SDA1, P1-05 = SCL1
smBus1 = smbus.SMBus(I2C_BUS_NUMBER) # global variable, cannot be set by a function
# * Register base addresses *
MCP23017BaseAddress1 = 0x22 # 1 LED, 1 button
MCP23008BaseAddress1 = 0x24 # 2 unipolar stepping motors
MCP23008BaseAddress2 = 0x25 # 1 decimal keypad
# * Port type *
PortA = 0
PortB = 1
# * Byte patterns *
# * Data bytes *
AllOutput = 0x00
AllHigh = 0xff
AllLow = 0x00
AlternateHighLow = 0xaa
AlternateLowHigh = 0x55
# * Direction setting bytes *
HalfHighHalfLow = 0xf0
HalfLowHalfHigh = 0x0f
Nibble1HighNibble2Low = 0xf0
Nibble1LowNibble2High = 0x0f
HighNibbleInputLowNibbleOutput = 0xf0
# * MCP23008/MCP23017 register address offsets *
InputOutputDirection = 0
InputPolarity = 1
InterruptOnChangeEnable = 2
InterruptOnChangeDefaultValue = 3
InterruptOnChangeMode = 4
Configuration = 5
PushPullOpenDrain = 6
InterruptFlag = 7
InterruptCapture = 8
PortStatus = 9
OutputLatch = 10
# * MCP23008/MCP23017 Band0/Band1 register address offset arrays *
RegisterAddressOffsetArray0 = [0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a,
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a]
RegisterAddressOffsetArray1 = [0x00, 0x02, 0x04, 0x06, 0x08, 0x0a, 0x11, 0x13, 0x15, 0x17, 0x19,
0x01, 0x03, 0x05, 0x07, 0x09, 0x10, 0x12, 0x14, 0x16, 0x18, 0x1a]
# * Setup MCP23008/MCP23017 ports all output *
def SetupMCP23008PortAllOutput(registerBaseAddress):
WriteDataByte(registerBaseAddress, RegisterAddressOffsetArray0, InputOutputDirection, PortA, AllOutput)
def SetupMCP23017BothPortAllOutput(registerBaseAddress):
WriteDataByte(registerBaseAddress, RegisterAddressOffsetArray0, InputOutputDirection, PortA, AllOutput)
WriteDataByte(registerBaseAddress, RegisterAddressOffsetArray0, InputOutputDirection, PortB, AllOutput)
# * Write/Read MCP23008/MCP23017 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
# * Test MCP23008/MCP23017 toggle port functions *
def ToggleMCP23008GP(registerBaseAddress, toggleTime, toggleCount):
SetupMCP23008PortAllOutput(registerBaseAddress)
for i in range(toggleCount):
WriteDataByte(registerBaseAddress, RegisterAddressOffsetArray0, OutputLatch, PortA, AllHigh)
sleep(toggleTime)
WriteDataByte(registerBaseAddress, RegisterAddressOffsetArray0, OutputLatch, PortA, AllLow)
sleep(toggleTime)
def ToggleMCP23017GP(registerBaseAddress, toggleTime, toggleCount):
SetupMCP23017BothPortAllOutput(registerBaseAddress)
for i in range(toggleCount):
WriteDataByte(registerBaseAddress, RegisterAddressOffsetArray0, OutputLatch, PortA, AllHigh)
WriteDataByte(registerBaseAddress, RegisterAddressOffsetArray0, OutputLatch, PortB, AllHigh)
sleep(toggleTime)
WriteDataByte(registerBaseAddress, RegisterAddressOffsetArray0, OutputLatch, PortA, AllLow)
WriteDataByte(registerBaseAddress, RegisterAddressOffsetArray0, OutputLatch, PortB, AllLow)
sleep(toggleTime)
def TestToggleMCP23008GP():
ToggleTime = 0.5
ToggleCount = 4
ToggleMCP23008GP(MCP23008BaseAddress1, ToggleTime, ToggleCount)
def TestToggleMCP23017GP():
ToggleTime = 0.5
ToggleCount = 4
ToggleMCP23008GP(MCP23017BaseAddress1, ToggleTime, ToggleCount)
# * MCP23008/MCP23017 Interrupt functions *
# * MCP23008 Interrupt setting *
def EnableInterruptOnChangeHighNibble(registerBaseAddress):
EnableInterruptHighNibble = 0xf0
WriteDataByte(registerBaseAddress, RegisterAddressOffsetArray0, InterruptOnChangeEnable, PortA, EnableInterruptHighNibble)
def SetInterruptOnChangeDefaultHighNibble(registerBaseAddress):
DefaultValueHighNibble = 0xf0 # GP4~7 (keypad rows input) interrupt default value = High
WriteDataByte(registerBaseAddress, RegisterAddressOffsetArray0, InterruptOnChangeDefaultValue, PortA, DefaultValueHighNibble)
def SetInterruptOnChangeCompareDefaultHighNibble(registerBaseAddress):
InterruptOnChangeDefaultValueHighNibble = 0xf0 # GP4~7 change from default value will cause interrupt
WriteDataByte(registerBaseAddress, RegisterAddressOffsetArray0, InterruptOnChangeMode, 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, RegisterAddressOffsetArray0, 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, RegisterAddressOffsetArray0, PushPullOpenDrain, PortA, OpenDrain)
def SetupInterruptHighNibbleCompareDefaultValueOpenDrainOutput(registerBaseAddress):
EnableInterruptOnChangeHighNibble(registerBaseAddress)
SetInterruptOnChangeDefaultHighNibble(registerBaseAddress)
SetInterruptOutputOpenDrain(registerBaseAddress)
# * Port A Interrupt checking *
def ReadInterruptFlagHighNibble(registerBaseAddress):
interruptFlagByte = ReadDataByte(registerBaseAddress, RegisterAddressOffsetArray0, InterruptFlag, PortA)
interruptFlagNibble = interruptFlagByte >> 4
return interruptFlagNibble
def ReadInterruptCaptureHighNibble(registerBaseAddress):
interruptCaptureByte = ReadDataByte(registerBaseAddress, RegisterAddressOffsetArray0, InterruptCapture, PortA)
interruptCaptureNibble = interruptCaptureByte >> 4
return interruptCaptureNibble
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 DetectInterrupt(registerBaseAddress):
while True:
interruptFlagNibble = ReadInterruptFlagHighNibble(registerBaseAddress)
interruptCaptureNibble = ReadInterruptCaptureHighNibble(registerBaseAddress)
print "Interrupt flag nibble = ", ConvertIntegerToFourBitPattern(interruptCaptureNibble)
sleep(2)
def TestDetectInterrupt():
RegisterBaseAddress = MCP23008BaseAddress2
SetupInterruptHighNibbleCompareDefaultValueOpenDrainOutput(RegisterBaseAddress)
DetectInterrupt(RegisterBaseAddress)
# *****************************************************************************
# * 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, RegisterAddressOffsetArray0, InputOutputDirection, PortA, AllOutput)
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, RegisterAddressOffsetArray0, OutputLatch, PortA, hexString1)
sleep(StepTime)
WriteDataByte(MCP23008BaseAddress1, RegisterAddressOffsetArray0, OutputLatch, PortA, hexString2)
sleep(StepTime)
def WriteMotorWindingFullStepSequence13232414(RegisterBaseAddress, NibbleType, StepCount, StepTime): #move motor using 13-23-24-14 sequence
# Set port all output
WriteDataByte(MCP23008BaseAddress1, RegisterAddressOffsetArray0, InputOutputDirection, PortA, AllOutput)
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, RegisterAddressOffsetArray0, OutputLatch, PortA, pattern)
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, FiftyMilliSeconds)
# OneBeep()
# WriteMotorWindingFullStepSequence13232414(MCP23008BaseAddress1, HighNibble, TwentyTimes, FiftyMilliSeconds)
def TestMotor():
MotorRegisterBaseAddress = MCP23008BaseAddress1
MoveTwoMotors(MotorRegisterBaseAddress)
# *****************************************************************************
# * Decimal keypad *
# 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
def SetupKeypad(registerBaseAddress):
HalfInputHalfOutput = 0xf0
WriteDataByte(registerBaseAddress, RegisterAddressOffsetArray0, InputOutputDirection, PortA, HalfInputHalfOutput)
def LoopUntilRowDataByteChange(registerBaseAddress):
NoKeyPressed = 0xf0
rowDataByte = NoKeyPressed
AllLowByte = 0x00
WriteDataByte(registerBaseAddress, RegisterAddressOffsetArray0, OutputLatch, PortA, AllLowByte)
while (rowDataByte == NoKeyPressed):
rowDataByte = GetRowDataByte(registerBaseAddress)
sleep(0.05) # debouncing time 50mS
def GetRowDataByte(registerBaseAddress):
rowDataByte = ReadDataByte(registerBaseAddress, RegisterAddressOffsetArray0, PortStatus, PortA)
return rowDataByte
def GetRowNumber(rowDataByte):
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, oldDataByte):
oldDataNibble = oldDataByte >> 4
WriteDataByte(registerBaseAddress, RegisterAddressOffsetArray0, OutputLatch, PortA, 0xf6)
newDataByte = ReadDataByte(registerBaseAddress, RegisterAddressOffsetArray0, PortStatus, PortA)
newDataNibble = newDataByte >> 4
if newDataNibble == oldDataNibble:
columnNumber = 0
return columnNumber
WriteDataByte(registerBaseAddress, RegisterAddressOffsetArray0, OutputLatch, PortA, 0xf5)
newDataByte = ReadDataByte(registerBaseAddress, RegisterAddressOffsetArray0, PortStatus, PortA)
newDataNibble = newDataByte >> 4
if newDataNibble == oldDataNibble:
columnNumber = 1
return columnNumber
WriteDataByte(registerBaseAddress, RegisterAddressOffsetArray0, OutputLatch, PortA, 0xf3)
newDataByte = ReadDataByte(registerBaseAddress, RegisterAddressOffsetArray0, PortStatus, PortA)
newDataNibble = newDataByte >> 4
if newDataNibble == oldDataNibble:
columnNumber = 2
return columnNumber
columnNumber = 99
return columnNumber
def GetKeyNumber(rowNumber, columnNumber):
keyNumber = (rowNumber * 3) + (columnNumber + 1)
return keyNumber
def GetKey(registerBaseAddress):
LoopUntilRowDataByteChange(registerBaseAddress)
rowDataByte = GetRowDataByte(registerBaseAddress)
rowNumber = GetRowNumber(rowDataByte)
columnNumber = GetColumnNumber(registerBaseAddress, rowDataByte)
keyNumber = GetKeyNumber(rowNumber, columnNumber)
return keyNumber
def GetKeyString(registerBaseAddress, count):
for i in range (count):
OneBeep()
keyNumber = GetKey(registerBaseAddress)
print "Key pressed = ", '{0:2}'.format(str(keyNumber).zfill(2).rjust(2))
def TestKeypad():
KeypadRegisterBaseAddress = MCP23008BaseAddress2
Count = 4
print "*** Decimal Keypad Test v2.0 TL Fong 2013jan08 *** "
print "Press keypad ", Count, "times."
SetupKeypad(KeypadRegisterBaseAddress)
GetKeyString(KeypadRegisterBaseAddress, Count)
FourBeeps()
print "End of keypad test."
# *****************************************************************************
# * Main test functions *
# * Setup RPi GPIO *
SetupGPIO()
StartBeep()
# * Part 1 - Test RPi GPIO *
# TestBuzzer() # beep buzzer 4 times
# TestLED() # blink LED 8 tmes
# TestButtonEchoBuzzer() # echo buton with buzzer 10 times
# TestButtonEchoLED() # echo button with LED 10 times
# TestToggleTxDpin() # toggle TxD pin every 2 seconds
# * Part 2 - Test MCP23008/MCP23017 *
# TestToggleMCP23008GP() # toggle MCP23008 output port
# TestToggleMCP23017GP() # toggle MCP23017 output ports
# TestMotor() # move two stepping motors
# TestPollingKeypad() # wait and get key 4 times
# * Part 3 - Test interrupts *
TestKeypad() # wait and get key 4 times
TestDetectInterrupt()
# *****************************************************************************
# End of Program
# *****************************************************************************
.END
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