Now I am tidying up things again.
First, the 200VAC/12VDC1A PSU, feeds to 7808 to get a 9V DC 1.5A PSU. The 9V supply feeds to LM2941 1A voltage regulator and adjusted to 5.25V 1A for Raspberry Pi.
So there are 12V, 8V, 5.25V outputs from this PSU.
The 5.25V 1A feeds to the Raspberry Pi. The RPi and the P1 connector have the following power and signal wires extended.
1. TP1/TP2
2. Reset
3. 3V3
4. 5V0
5. I2C (SCL1, SDA1)
6. GPIO Gen1, 4, 5, 6
7. TxD, RxD
Now the RPi's power and signal lines go to the power signal routing board.
This power signal routing board connect to the following.
1. 3V3 / 5V0 power (at left edge connector).
2. TP1/TP2 to DVM which now shows 4.98V
3. Reset button to software reset RPi
4. LED connected to Gen1, Buzzer to Gen 4, and Button to Gen 5
5. SDA1, SCL1, Gen6, TxD, RxD
The power/signal routing board's output goes to the 5 channel, 2N7000 based 3V3/5V0 level shifters. The 5 level shifters shift to/from 3V3, 5V0 the following signals SCL1, SDA1, Gen6, TxD, RxD.
There are two HC04 hex inverters, one powered at 3V3, the other 5V0 with input from Gen6 (3V3 side) and Gen6 (5V0 side) and drives the two red/green LED pairs. These LED pairs will be used to indicate the interrupt signal from the to follow MCP23008/MCP23017 IO expanders.
Now the MCP23017 16 bit IO Expander board comes in. This board gets 5V power, no longer from RPi, but from another power connector from the 5.25V PSU. This board gets the following 5 signals through a 6 wire DuPoint cabe/connector from the level shifter board.
Pin 1 = Gnd
Pin2 = SLC1
Pin3 = SDA1
Pin4 = Gen6
Pin5 = TxD
Pin6 = RxD
The board outputs the folowing.
1. INTA, INTB
2. GPA0~7
3. GPB0~7
This board has a 6 pin male connector which can daisy chain the I2C/Gen6/UART signals further.
After the tidying up, I use the following program to make sure again, the toggling Port A, Port B, and both ports are OK, which means that no careless wrong connections have been made.
#testToggleMCP23017PortB()
testToggleMCP23017BothPort()
Next step is to see if I can test the MCP23008 8 bit IO expander board.
.END
# *****************************************************************************
# *** tiox14.py ***
# Program - Test MCP23017
# Version - 1.4
# Date - 2012nov30
# Update - 2013jan03
# Author - tlfong01
# File - tiox14_2013jan04.py
# Blog - http://tlfong01.blogspot.hk/
# Purpose - test basics of Raspberry Pi GPIO
# 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
# *****************************************************************************
# *** Configure RPi GPIO pins ***
# * 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]
# *****************************************************************************
# *** Constants ***
# * General - counts, time periods, nibble types *
TWO_TIMES = 2
FOUR_TIMES = 4
EIGHT_TIMES = 8
TEN_TIMES = 10
TWENTY_TIMES = 20
FIFTY_TIMES = 50
ONE_HUNDRED_TIMES = 100
TWO_HUNDRED_TIMES = 200
FOUR_HUNDRED_TIMES = 400
TWENTY_MILLI_SECONDS = 0.02
FIFTY_MILLI_SECONDS = 0.05
TENTH_SECOND = 0.1
QUARTER_SECOND = 0.25
HALF_SECOND = 0.5
ONE_SECOND = 1
ONE_AND_HALF_SECONDS = 1.5
TWO_SECONDS = 2
ON_TIME = TENTH_SECOND
OFF_TIME = QUARTER_SECOND
BUTTON_DEBOUNCING_TIME = QUARTER_SECOND
TEST_TIME = 0.05
LOW_NIBBLE = 0
HIGH_NIBBLE = 1
BOTH_NIBBLE = 2 # full byte of 8 bits
# * Device constants *
# LED and buzzer states
OFF = False
ON = True
# Button states
PRESSED = False
RELEASED = True
# *****************************************************************************
# *** RPi GPIO functions ***
# Reference - Raspberry Pi Python GPIO Version - GPIO 0.4.1a
# http://pypi.python.org/pypi/RPi.GPIO/0.4.1a
# RPi Model B 5V0 max current draw: 50 mA
# RPi Model B 3V3 max current draw: 300 mA
# GPIO maximum current draw per pin: 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) == RELEASED:
pass
else:
pulsePin(oPin, ON_TIME, OFF_TIME)
break
continue
def togglePin(oPin, toggleTime): # toggle pin
writeOutputPin(oPin, ON)
sleep(toggleTime)
writeOutputPin(oPin, OFF)
sleep(toggleTime)
# * Test GPIO functions *
def testBuzzer(): # beep 4 times
setupGPIO()
for i in range (FOUR_TIMES):
pulsePin(BuzzerPin, ON_TIME, OFF_TIME)
def testLED(): # blink 8 times
setupGPIO()
for i in range (EIGHT_TIMES):
pulsePin(LEDpin, ON_TIME, OFF_TIME)
def testButtonEchoBuzzer(): #
setupGPIO()
for i in range (TEN_TIMES):
echoPin(ButtonPin, BuzzerPin)
def testButtonEchoLED(): #
setupGPIO()
for i in range (TEN_TIMES):
echoPin(ButtonPin, LEDpin)
def testToggleTxDpin():
while True:
togglePin(TxDpin, TWO_SECONDS)
# *****************************************************************************
# *** Beep functions ***
def beep(count):
for i in range(count):
pulsePin(BuzzerPin, ON_TIME, OFF_TIME)
def startBeep():
beep(TWO_TIMES)
sleep(1)
def endBeep():
beep(FOUR_TIMES)
def oneBeep():
beep(1)
# *****************************************************************************
# *** IO Expander 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
# * 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
# * MCP23008 device addresses *
MCP23008_1_REGISTER_BASE_ADDRESS = 0x20
MCP23008_2_REGISTER_BASE_ADDRESS = 0x21
# * MCP23008 register addresses *
IO_DIRECTION_REGISTER = IODIR_REG = 0x00
INTERRUPT_ON_CHANGE_REGISTER = GPINTEN = 0x02
DEFAULT_COMPARE_VALUE_REGISTER = DEFVAL = 0x03
INTERRUPT_CONTROL_REGISTER = INTCON = 0x04
IO_CONTROL_REGISTER = IOCON = 0x05
INTERRUPT_FLAG_REGISTER = INTF = 0x07
INTERRUPT_CAPTURE_REGISTER = INTCAP = 0x08
GPIO_REGISTER = GPIO_REG = 0x09
OUTPUT_LATCH_REGISTER = OLAT_REG = 0x0a
# * MCP23017 device addresses *
MCP23017_1_REGISTER_BASE_ADDRESS = 0x22
MCP23017_2_REGISTER_BASE_ADDRESS = 0x23
# * MCP23017 set bank map mode *
SET_BANK_MAP_0 = 0x00
SET_BANK_MAP_1 = 0x80
# * MCP23017 Bank number and Port Group *
BANK_MAP_0 = 0
BANK_MAP_1 = 1
PORT_GROUP_A = 0
PORT_GROUP_B = 1
PortA = 0
PortB = 1
# ****************************************************************************
# * MCP23017 functions *
Mcp23017BaseAddress1 = 0x22
# * Register address array indexes *
InputOutputDirection = 0
InputPolarity = 1
InterruptOnChangeEnable = 2
InterruptOnChangeDefaultValue = 3
InterruptOnChangeMode = 4
Configuration = 5
PullUpResistor = 6
InterruptFlag = 7
InterruptCapture = 8
PortStatus = 9
OutputLatch = 10
# * Registerr address arrays *
Band0RegisterAddressArray = [0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a,
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a]
Band1RegisterAddressArray = [0x00, 0x02, 0x04, 0x06, 0x08, 0x0a, 0x11, 0x13, 0x15, 0x17, 0x19,
0x01, 0x03, 0x05, 0x07, 0x09, 0x10, 0x12, 0x14, 0x16, 0x18, 0x1a]
# * Set IO direction *
def setIoDirection(registerBaseAddress, registerAddressArray, portType, directionByte):
if portType == 0:
addressOffset = registerAddressArray[InputOutputDirection]
else:
addressOffset = registerAddressArray[InputOutputDirection + 11]
smBus1.write_byte_data(registerBaseAddress, addressOffset, directionByte)
def setBothPortsOutput(registerBaseAddress, registerAddressArray):
directionByte = 0x00 # all output
portType = 0 # Port A
setIoDirection(registerBaseAddress, registerAddressArray, portType, directionByte)
portType = 1 # Port B
setIoDirection(registerBaseAddress, registerAddressArray, portType, directionByte)
# * Write data *
def writeData(registerBaseAddress, registerAddressArray, portType, dataByte):
if portType == 0:
addressOffset = registerAddressArray[OutputLatch]
else:
addressOffset = registerAddressArray[OutputLatch + 11]
smBus1.write_byte_data(registerBaseAddress, addressOffset, dataByte)
def writeAportHigh(registerBaseAddress, registerAddressArray):
dataByte = 0xff # All 8 bits High
portType = 0 # Port A
writeData(registerBaseAddress, registerAddressArray, portType, dataByte)
def writeBportHigh(registerBaseAddress, registerAddressArray):
dataByte = 0xff # All 8 bits High
portType = 1 # Port B
writeData(registerBaseAddress, registerAddressArray, portType, dataByte)
def writeBothPortsHigh(registerBaseAddress, registerAddressArray):
writeAportHigh(registerBaseAddress, registerAddressArray)
writeBportHigh(registerBaseAddress, registerAddressArray)
def writeAportLow(registerBaseAddress, registerAddressArray):
dataByte = 0x00 # All 8 bits Low
portType = 0 # Port A
writeData(registerBaseAddress, registerAddressArray, portType, dataByte)
def writeBportLow(registerBaseAddress, registerAddressArray):
dataByte = 0x00 # All 8 bits Low
portType = 1 # Port B
writeData(registerBaseAddress, registerAddressArray, portType, dataByte)
def toggleAport(registerBaseAddress, registerAddressArray, time, count):
for i in range(count):
writeAportHigh(registerBaseAddress, registerAddressArray)
sleep(time)
writeAportLow(registerBaseAddress, registerAddressArray)
sleep(time)
def toggleBport(registerBaseAddress, registerAddressArray, time, count):
for i in range(count):
writeBportHigh(registerBaseAddress, registerAddressArray)
sleep(time)
writeBportLow(registerBaseAddress, registerAddressArray)
sleep(time)
def toggleBothPorts(registerBaseAddress, registerAddressArray, time, count):
for i in range(count):
writeAportHigh(registerBaseAddress, registerAddressArray)
writeBportHigh(registerBaseAddress, registerAddressArray)
sleep(time)
writeAportLow(registerBaseAddress, registerAddressArray)
writeBportLow(registerBaseAddress, registerAddressArray)
sleep(time)
def testToggleMCP23017PortA():
setBothPortsOutput(Mcp23017BaseAddress1, Band0RegisterAddressArray)
toggleAport(Mcp23017BaseAddress1, Band0RegisterAddressArray, 1, 10) # toggle 1 second, 10 times
def testToggleMCP23017PortB():
setBothPortsOutput(Mcp23017BaseAddress1, Band0RegisterAddressArray)
toggleBport(Mcp23017BaseAddress1, Band0RegisterAddressArray, 1, 10) # toggle 1 second, 10 times
def testToggleMCP23017BothPort():
setBothPortsOutput(Mcp23017BaseAddress1, Band0RegisterAddressArray)
toggleBothPorts(Mcp23017BaseAddress1, Band0RegisterAddressArray, 1, 10) # toggle 1 second, 10 times
# ****************************************************************************
# * Direction setting *
DIRECTION_BYTE_ALL_OUTPUT = 0x00
DIRECTION_BYTE_LOW_NIBBLE_OUTPUT_HIGH_NIBBLE_INPUT = 0xf0
# * Data pattern *
DATA_BYTE_ALL_ZERO = 0x00
DATA_BYTE_ALL_ONE = 0xff
DATA_BYTE_HIGH_NIBBLE_ONE_LOW_NIBBLE_ZERO = 0xf0
DATA_BYTE_HIGH_NIBBLE_ZERO_LOW_NIBBLE_ONE = 0x0f
# * Interrupt setting *
ENABLE_INTERRUPT_HIGH_NIBBLE = 0xf0
DEFAULT_COMPARE_VALUE_HIGH_NIBBLE = 0xf0
INTERRUPT_CONTROL_COMPARE_DEFAULT_HIGH_NIBBLE = 0xf0
INTERRUPT_PIN_PUSH_PULL_DRIVER_HIGH_ACTIVE = 0b00111010 # 0x3a, no auto add incre, no slew rate
INTERRUPT_PIN_OPEN_DRAIN = 0b00111000 # 0x38, no auto add incre, no slew rate
# * Setup IO direction *
def setIOxPinsAllOutput(registerBaseAddress): # set up all 8 IOx pins as output
#smBus1.write_byte_data(registerBaseAddress, IO_DIRECTION_REGISTER, DIRECTION_BYTE_ALL_OUTPUT)
smBus1.write_byte_data(registerBaseAddress, 0x10, DIRECTION_BYTE_ALL_OUTPUT)
def setIOxPinsLowNibbleOutputHighNibbleInput(registerBaseAddress): # set low nibble output, high nibble input
smBus1.write_byte_data(registerBaseAddress, IO_DIRECTION_REGISTER, DIRECTION_BYTE_LOW_NIBBLE_OUTPUT_HIGH_NIBBLE_INPUT)
# * Writing data *
def writeIOxPinsAllLow(registerBaseAddress): # write zeros to all 8 IOx output pins
#smBus1.write_byte_data(registerBaseAddress, OUTPUT_LATCH_REGISTER, DATA_BYTE_ALL_ZERO)
smBus1.write_byte_data(registerBaseAddress, 0x1a, DATA_BYTE_ALL_ZERO)
def writeIOxPinsAllHigh(registerBaseAddress): #write ones to all 8 IOx output pins
#smBus1.write_byte_data(registerBaseAddress, OUTPUT_LATCH_REGISTER, DATA_BYTE_ALL_ONE)
smBus1.write_byte_data(registerBaseAddress, 0x1a, DATA_BYTE_ALL_ONE)
def writeIOxPins(registerBaseAddress, dataHexString): # write 8 bit hex string to IOx output pins
#smBus1.write_byte_data(registerBaseAddress, OUTPUT_LATCH_REGISTER, dataHexString)
smBus1.write_byte_data(registerBaseAddress, 0x1a, dataHexString)
# * Reading data *
def readIOxPinsByte(registerBaseAddress): # read 8 bit hex data from GPIO register (= 8 output pin)
hexByte = smBus1.read_byte_data(registerBaseAddress, GPIO_REGISTER)
return hexByte
def readIOxPinsHighNibble(registerBaseAddress): # read high nibble from GPIO resister (= upper nible of output pins)
hexByte = readIOxPinsByte(registerBaseAddress)
hexNibble = hexByte >> 4
return hexNibble
# * Interrupt setting *
def enableInterruptOnChangeHighNibble(registerBaseAddress): # enable high nibble interrupt on change
smBus1.write_byte_data(registerBaseAddress, INTERRUPT_ON_CHANGE_REGISTER, ENABLE_INTERRUPT_HIGH_NIBBLE)
def setInterruptOnChangeDefaultHighNibble(registerBaseAddress): # set high nibble default compare values
smBus1.write_byte_data(registerBaseAddress, DEFAULT_COMPARE_VALUE_REGISTER, DEFAULT_COMPARE_VALUE_HIGH_NIBBLE)
def setInterruptOnChangeCompareDefaultHighNibble(registerBaseAddress): # enable high nibble compare default
smBus1.write_byte_data(registerBaseAddress, INTERRUPT_CONTROL_REGISTER, INTERRUPT_CONTROL_COMPARE_DEFAULT_HIGH_NIBBLE)
def setHighNibbleCompareDefault(registerBaseAddress): # set high nibble compare default
enableInterruptOnChangeHighNibble(registerBaseAddress)
setInterruptOnChangeDefaultHighNibble(registerBaseAddress)
setInterruptOnChangeCompareDefaultHighNibble(registerBaseAddress)
def setInterruptPinPushPullHighActive(registerBaseAddress): # interrupt pin push pull high active, no auto add inc, no slew rate
smBus1.write_byte_data(registerBaseAddress, IO_CONTROL_REGISTER, INTERRUPT_PIN_PUSH_PULL_DRIVER_HIGH_ACTIVE)
def setInterruptPinOpenDrain(registerBaseAddress): # interrupt pin open drain, no auto add inc, no slew rate
smBus1.write_byte_data(registerBaseAddress, IO_CONTROL_REGISTER, INTERRUPT_PIN_OPEN_DRAIN)
# * Interrupt reading *
def readInterruptFlagPinsHighNibble(registerBaseAddress): # read high nibble interrupt flag register
hexByte = smBus1.read_byte_data(registerBaseAddress, INTERRUPT_FLAG_REGISTER)
hexNibble = hexByte >> 4
return hexNibble
def readInterruptCapturePinsHighNibble(registerBaseAddress): # read high nibble interrupt capture register
hexByte = smBus1.read_byte_data(registerBaseAddress, INTERRUPT_CAPTURE_REGISTER)
hexNibble = hexByte >> 4
return hexNibble
# * Blink LED *
def switchOffAll8LEDs(RegisterBaseAddress):
writeIOxPinsAllLow(RegisterBaseAddress)
def switchOnfAll8LEDs(RegisterBaseAddress):
writeIOxPinsAllHigh(RegisterBaseAddress)
def blink8LEDs(RegisterBaseAddress, OnTime, OffTime, Count):
setIOxPinsAllOutput(RegisterBaseAddress)
for i in range(Count):
writeIOxPinsAllHigh(RegisterBaseAddress)
sleep(OnTime)
writeIOxPinsAllLow(RegisterBaseAddress)
sleep(OffTime)
def blink4LEDs(RegisterBaseAddress, OnTime, OffTime, Count):
setIOxPinsLowNibbleOutputHighNibbleInput(RegisterBaseAddress)
for i in range(Count):
writeIOxPinsAllHigh(RegisterBaseAddress)
sleep(OnTime)
writeIOxPinsAllLow(RegisterBaseAddress)
sleep(OffTime)
# * Testing *
def blink8LEDsMCP230080x20():
blink8LEDs(MCP23008_1_REGISTER_BASE_ADDRESS, HALF_SECOND, ONE_SECOND, FOUR_TIMES)
def blink4LEDsMCP230080x21():
blink4LEDs(MCP23008_2_REGISTER_BASE_ADDRESS, HALF_SECOND, ONE_SECOND, FOUR_TIMES)
def blink8LEDsMCP23017(deviceAddress, bankNumber, portGroup):
setBankNumberPortGroup(bankNumber, portGroup)
blink8LEDs(deviceAddress, HALF_SECOND, HALF_SECOND, FOUR_TIMES)
def testInterruptPinFallingEdgeDetection():
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"
# *****************************************************************************
# *** Unipolar Stepping Motor 28BYJ48 etc ***
# 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 Yellow/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
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))
# * Move unipolar stepping motor *
def writeSequence_13_24(RegisterBaseAddress, NibbleType, StepCount, StepTime): # move motor using 13-24 sequence
setIOxPinsAllOutput(RegisterBaseAddress)
if NibbleType == LOW_NIBBLE:
hexString1 = convert2PinToHex(1, 3)
hexString2 = convert2PinToHex(2, 4)
else:
hexString1 = convert2PinToHighNibble(1, 3)
hexString2 = convert2PinToHighNibble(2, 4)
for i in range(StepCount):
writeIOxPins(RegisterBaseAddress, hexString1)
sleep(StepTime)
writeIOxPins(RegisterBaseAddress, hexString2)
sleep(StepTime)
def writeSequence_13_23_24_14(RegisterBaseAddress, NibbleType, StepCount, StepTime): #move motor using 13-23-24-14 sequence
setIOxPinsAllOutput(RegisterBaseAddress)
if NibbleType == LOW_NIBBLE:
motorWindingActivationPatternArray = (0x05, 0x06, 0x0a, 0x09)
else:
motorWindingActivationPatternArray = (0x50, 0x60, 0xa0, 0x90)
for i in range(StepCount):
for pattern in motorWindingActivationPatternArray:
writeIOxPins(RegisterBaseAddress, pattern)
sleep(StepTime)
def move2MotorsUsingMCP23008_1(): # move 2 motors one after another
oneBeep()
writeSequence_13_24(MCP23008_1_REGISTER_BASE_ADDRESS, LOW_NIBBLE, TWENTY_TIMES, FIFTY_MILLI_SECONDS)
oneBeep()
writeSequence_13_24(MCP23008_1_REGISTER_BASE_ADDRESS, HIGH_NIBBLE, ONE_HUNDRED_TIMES, TWENTY_MILLI_SECONDS)
oneBeep()
writeSequence_13_23_24_14(MCP23008_1_REGISTER_BASE_ADDRESS, LOW_NIBBLE, TWENTY_TIMES, FIFTY_MILLI_SECONDS)
oneBeep()
writeSequence_13_23_24_14(MCP23008_1_REGISTER_BASE_ADDRESS, HIGH_NIBBLE, ONE_HUNDRED_TIMES, TWENTY_MILLI_SECONDS)
def move1MotorUsingMCP23008_2(RegisterBaseAddress, OnTime, OffTime, BlinkCount, CycleCount, StepTime ): # move motor on MCP23008 #2
setIOxPinsLowNibbleOutputHighNibbleInput(RegisterBaseAddress)
oneBeep
for i in range(BlinkCount):
writeIOxPinsAllHigh(RegisterBaseAddress)
sleep(OnTime)
writeIOxPinsAllLow(RegisterBaseAddress)
sleep(OffTime)
oneBeep()
writeSequence_13_24(RegisterBaseAddress, LOW_NIBBLE, CycleCount, StepTime)
# *****************************************************************************
# *** 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 row ports
# 4. Wait for interrupt
# 5. Pressing any key would cause an interrupt
# 6. When interrupt occurs check which row reads LOW
# 7. Write LOW only to column GP0, if row port still LOW, then this column 0
# has a key pressed, if not, check if column 1, if not column 3.
# 8. Calculate the key using the column and row data.
# Read MCP23008 GP4 ~ GP7
def testReadGP4567(): # read keypad input rows 0~3
RegisterBaseAddress = MCP23008_2_REGISTER_BASE_ADDRESS
setIOxPinsLowNibbleOutputHighNibbleInput(RegisterBaseAddress)
writeIOxPinsAllLow(RegisterBaseAddress)
nibble = 0xf0
while True:
oneBeep()
sleep(1)
nibble = smBus1.read_byte_data(RegisterBaseAddress, GPIO_REGISTER)
print "GP4 to GP7 = ", hex(nibble)
## * keypad base address and smBus setting *
keypadRegisterBaseAddress = MCP23008_2_REGISTER_BASE_ADDRESS
keypadSmBus = smBus1
# * Keypad columns numbering *
ColumnOutputPin0 = 0
ColumnOutputPin1 = 1
ColumnOutputPin2 = 2
ColumnOutputPinTuple = ColumnOutputPin0, ColumnOutputPin1, ColumnOutputPin2
# * Keypad row numbering *
RowInputPin0 = 0
RowInputPin1 = 1
RowInputPin2 = 2
RowInputPin3 = 3
RowInputPinTuple = RowInputPin0, RowInputPin1, RowInputPin2, RowInputPin2
# * Keypad matrix numbering *
KeyPadMatrixTuple = ColumnOutputPinTuple, RowInputPinTuple
# * Write keypad column data patterns *
ColumnAllLow = 0b000
Column0Low = 0b110
Column1Low = 0b101
Column2Low = 0b011
ColumnLowTuple = Column0Low, Column1Low, Column2Low
# * Read keypad data patterns *
RowAllHigh = 0b1111
Row0Low = 0b1110
Row1Low = 0b1101
Row2Low = 0b1011
Row3Low = 0b0111
RowLowTuple = Row0Low, Row1Low, Row2Low, Row3Low
# * Set, write, read keypad pins *
def assignKeypadReadWritePins(keypadRegisterBaseAddress):
setIOxPinsLowNibbleOutputHighNibbleInput(keypadRegisterBaseAddress)
def writeColumnPins(keypadRegisterBaseAddress, columnPattern):
hexString = 0xff & columnPattern
writeIOxPins(keypadRegisterBaseAddress, hexString)
def readRowPins():
hexNibble = readIOxPinsHighNibble(keypadRegisterBaseAddress)
return hexNibble
# * test polling/interrupt keypad *
def scanKeypad(registerBaseAddress):
assignKeypadReadWritePins(registerBaseAddress)
setInterruptPinOpenDrain(registerBaseAddress) # *** interrupt pin open drain !!!
writeColumnPins(registerBaseAddress, ColumnAllLow)
setHighNibbleCompareDefault(registerBaseAddress) # *** testing interrupt ***
# Loop until one key pressed
keyPressed = False
while True:
nibble = readRowPins()
if nibble == Row0Low:
row = 0
keyPressed = True
print "Row 0 key pressed"
elif nibble == Row1Low:
row = 1
keyPressed = True
print "Row 1 key pressed"
elif nibble == Row2Low:
row = 2
keyPressed = True
print "Row 2 key pressed"
elif nibble == Row3Low:
row = 3
keyPressed = True
print "Row 3 key pressed"
else:
row = 9
#print "No key or more than one key pressed"
if keyPressed == True:
# Check which column the key is pressed
column = 9
writeColumnPins(registerBaseAddress, Column0Low)
nibble = readRowPins()
if nibble != RowAllHigh:
column = 0
print "Column 0 key pressed"
else:
writeColumnPins(registerBaseAddress, Column1Low)
nibble = readRowPins()
if nibble != RowAllHigh:
column = 1
print "Column 1 key pressed"
else:
writeColumnPins(registerBaseAddress, Column2Low)
nibble = readRowPins()
if nibble != RowAllHigh:
column = 2
print "Column 2 key pressed"
else:
print "Error"
# Calculate which key pressed
keyNumber = (row * 3) + (column + 1)
print "Key pressed = ", '{0:8}'.format(str(keyNumber).zfill(2).rjust(10))
# *******************************************************************************
# checking interrupt
# *******************************************************************************
# Check which column interrupt
interruptFlagNibble = readInterruptFlagPinsHighNibble(registerBaseAddress)
interruptCaptureNibble = readInterruptCapturePinsHighNibble(registerBaseAddress)
print "Interrupt flag nibble = ", '{0:8}'.format((str(bin(interruptFlagNibble)).zfill(4)).rjust(10))
print "Interrupt capture nibble = ", '{0:8}'.format((str(bin(interruptCaptureNibble)).zfill(4)).rjust(10))
keyPressed = False
sleep(1)
else:
pass
def testScanKeypad():
scanKeypad(MCP23008_2_REGISTER_BASE_ADDRESS)
# *****************************************************************************
# * Old test functions *
# testLEDandBuzzer()
# testButton() !!! not working !!!
# blink8LEDsIOx1()
# blink4LEDsIOx2()
# testConvert1PinToHex()
# blink4LEDsIOx2()
# move1MotorUsingMCP23008_2(MCP23008_2_REGISTER_BASE_ADDRESS, HALF_SECOND,
# ONE_SECOND, FOUR_TIMES, TWENTY_TIMES, ONE_SECOND)
# *****************************************************************************
# *** Old test functions ***
#setupGPIO()
#startBeep()
#blink4LEDsIOx2() # OK 2012dec14
#testReadGP4567() # OK 2012dec14
#testScanKeypad()
#endBeep()
# *****************************************************************************
# *** Current test functions ***
#testBuzzer() # beep buzzer 4 times
#testLED() # blink LED 8 tmes
#testButtonEchoBuzzer() # echo buton with buzzer 10 times
#testButtonEchoLED() # echo buton with LED 10 times
#testToggleTxDpin() # toggle TxD pin every 2 seconds
setupGPIO()
startBeep()
#testToggleMCP23017PortA()
#testToggleMCP23017PortB()
testToggleMCP23017BothPort()
# *****************************************************************************
# End of Program
# *****************************************************************************
.END
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