def init_ABE():
# Create an instance of the IOPi class with an I2C address of 0x20
iobus = IOPi(0x21)
# Create an instance of the Servo class with an I2C address of 0x40
# Servo(Address, Low_Limit, High_Limit)
# If servo is not getting full range of motion
# Decrease low limit by 0.1 until servo does not move
# Increase high limit by 0.1 until servo does not move
servo = Servo(0x40, LOW_LIMIT, HIGH_LIMIT)
# We will read the inputs 1 to 16 from the I/O bus so set port 0 and
# port 1 to be inputs and enable the internal pull-up resistors
iobus.set_port_direction(0, 0xFF)
iobus.set_port_pullups(0, 0xFF)
iobus.set_port_direction(1, 0xFF)
iobus.set_port_pullups(1, 0xFF)
iobus.invert_port(0, 0xFF)
iobus.invert_port(1, 0xFF)
# Enable servo outputs
servo.output_enable()
return iobus, servo
def main():
"""
Main program function
"""
iobus2 = IOPi(0x21)
iobus2.set_pin_direction(2, 0)
iobus2.set_pin_direction(4, 0)
iobus2.set_pin_direction(10, 1)
iobus2.set_pin_direction(14, 1)
iobus2.set_port_pullups(1, 0xFF)
while True:
# clear the console
if iobus2.read_pin(14) == 0:
iobus2.write_pin(2, 1)
else:
iobus2.write_pin(2, 0)
if iobus2.read_pin(10) == 0:
iobus2.write_pin(4, 1)
else:
iobus2.write_pin(4, 0)
def main():
'''
Main program function
'''
iobus = IOPi(0x20, False)
# We will read the inputs 1 to 16 from the I/O bus so set port 0,
# port 1 to be inputs and enable the internal pull-up resistors
iobus.set_port_direction(0, 0xA1)
print("Port direction 0: " + hex(iobus.get_port_direction(0)))
iobus.set_port_direction(1, 0xB1)
print("Port direction 1: " + hex(iobus.get_port_direction(1)))
iobus.set_port_pullups(0, 0xC1)
print("Port pullups 0: " + hex(iobus.get_port_pullups(0)))
iobus.set_port_pullups(1, 0xD1)
print("Port pullups 1: " + hex(iobus.get_port_pullups(1)))
iobus.invert_port(0, 0xE1)
print("Invert Port 0: " + hex(iobus.get_port_polarity(0)))
iobus.invert_port(1, 0xF1)
print("Invert Port 1: " + hex(iobus.get_port_polarity(1)))
def main():
'''
Main program function
'''
# Create an instance of the IOPi class with an I2C address of 0x20
iobus = IOPi(0x20)
# Set all pins on the IO bus to be inputs with internal pull-ups enabled.
iobus.set_port_pullups(0, 0xFF)
iobus.set_port_pullups(1, 0xFF)
iobus.set_port_direction(0, 0xFF)
iobus.set_port_direction(1, 0xFF)
# invert the ports so pulling a pin to ground will show as 1 instead of 0
iobus.invert_port(0, 0xFF)
iobus.invert_port(1, 0xFF)
# Set the interrupt polarity to be active high and mirroring enabled, so
# pin 1 will trigger both INT A and INT B when a pin is grounded
iobus.set_interrupt_polarity(1)
iobus.mirror_interrupts(1)
# Set the interrupts default value to 0
iobus.set_interrupt_defaults(0, 0x00)
iobus.set_interrupt_defaults(1, 0x00)
# Set the interrupt type to be 1 for ports A and B so an interrupt is
# fired when a state change occurs
iobus.set_interrupt_type(0, 0x00)
iobus.set_interrupt_type(1, 0x00)
# Enable interrupts for pin 1
iobus.set_interrupt_on_port(0, 0x01)
iobus.set_interrupt_on_port(1, 0x00)
timer = threading.Thread(target=background_thread(iobus))
timer.daemon = True # set thread to daemon ('ok' won't be printed)
timer.start()
while 1:
"""
Do something in the main program loop while the interrupt checking
is carried out in the background
"""
# wait 1 seconds
time.sleep(1)
def main():
'''
Main program function
'''
# Create an instance of the IOPi class with an I2C address of 0x20
iobus = IOPi(0x20)
# Set all pins on the IO bus to be inputs with internal pull-ups enabled.
iobus.set_port_pullups(0, 0xFF)
iobus.set_port_pullups(1, 0xFF)
iobus.set_port_direction(0, 0xFF)
iobus.set_port_direction(1, 0xFF)
# invert the ports so pulling a pin to ground will show as 1 instead of 0
iobus.invert_port(0, 0xFF)
iobus.invert_port(1, 0xFF)
# Set the interrupt polarity to be active high and mirroring enabled, so
# pin 1 will trigger both INT A and INT B when a pin is grounded
iobus.set_interrupt_polarity(1)
iobus.mirror_interrupts(1)
# Set the interrupts default value to 0
iobus.set_interrupt_defaults(0, 0x00)
iobus.set_interrupt_defaults(1, 0x00)
# Set the interrupt type to be 1 for ports A and B so an interrupt is
# fired when a state change occurs
iobus.set_interrupt_type(0, 0x00)
iobus.set_interrupt_type(1, 0x00)
# Enable interrupts for pin 1
iobus.set_interrupt_on_port(0, 0x01)
iobus.set_interrupt_on_port(1, 0x00)
timer = threading.Thread(target=background_thread(iobus))
timer.daemon = True # set thread to daemon ('ok' won't be printed)
timer.start()
while 1:
"""
Do something in the main program loop while the interrupt checking
is carried out in the background
"""
# wait 1 seconds
time.sleep(1)
def main():
'''
Main program function
'''
# Create two instances of the IOPi class with
# I2C addresses of 0x20 and 0x21
busin = IOPi(0x20)
busout = IOPi(0x21)
# Set port 0 on the busin bus to be inputs with internal pull-ups enabled.
busin.set_port_pullups(0, 0xFF)
busin.set_port_direction(0, 0xFF)
# Invert the port so pins will show 1 when grounded
busin.invert_port(0, 0xFF)
# Set port 0 on busout to be outputs and set the port to be off
busout.set_port_direction(0, 0x00)
busout.write_port(0, 0x00)
# Set the interrupts default value for port 0 to 0x00 so the interrupt
# will trigger when any pin registers as true
busin.set_interrupt_defaults(0, 0x00)
# Set the interrupt type to be 1 on each pin for port 0 so an interrupt is
# fired when the pin matches the default value
busin.set_interrupt_type(0, 0xFF)
# Enable interrupts for all pins on port 0
busin.set_interrupt_on_port(0, 0xFF)
# Reset the interrupts
busin.reset_interrupts()
while True:
# read the interrupt status for each port.
if (busin.read_interrupt_status(0) != 0):
# If the status is not 0 then an interrupt has occured
# on one of the pins so read the value from the interrupt capture
value = busin.read_interrupt_capture(0)
# write the value to port 0 on the busout bus
busout.write_port(0, value)
# sleep 200ms before checking the pin again
time.sleep(0.2)
def main():
'''
Main program function
'''
# Create two instances of the IOPi class with
# I2C addresses of 0x20 and 0x21
ioin = IOPi(0x20)
ioout = IOPi(0x21)
# Set port 0 on the ioin bus to be inputs with internal pull-ups enabled.
ioin.set_port_pullups(0, 0xFF)
ioin.set_port_direction(0, 0xFF)
# Invert the port so pins will show 1 when grounded
ioin.invert_port(0, 0xFF)
# Set port 0 on ioout to be outputs and set the port to be off
ioout.set_port_direction(0, 0x00)
ioout.write_port(0, 0x00)
# Set the interrupts default value for port 0 to 0x00 so the interrupt
# will trigger when any pin registers as true
ioin.set_interrupt_defaults(0, 0x00)
# Set the interrupt type to be 1 on each pin for port 0 so an interrupt is
# fired when the pin matches the default value
ioin.set_interrupt_type(0, 0xFF)
# Enable interrupts for all pins on port 0
ioin.set_interrupt_on_port(0, 0xFF)
# Reset the interrupts
ioin.reset_interrupts()
while True:
# read the interrupt status for each port.
if (ioin.read_interrupt_status(0) != 0):
# If the status is not 0 then an interrupt has occured
# on one of the pins so read the value from the interrupt capture
value = ioin.read_interrupt_capture(0)
# write the value to port 0 on the ioout bus
ioout.write_port(0, value)
# sleep 200ms before checking the pin again
time.sleep(0.2)
def main():
'''
Main program function
'''
# Create an instance of the IOPi class with an I2C address of 0x20
iobus = IOPi(0x20)
# Set all pins on the IO bus to be inputs with internal pull-ups enabled.
iobus.set_port_pullups(0, 0xFF)
iobus.set_port_pullups(1, 0xFF)
iobus.set_port_direction(0, 0xFF)
iobus.set_port_direction(1, 0xFF)
# Invert both ports so pins will show 1 when grounded
iobus.invert_port(0, 0xFF)
iobus.invert_port(1, 0xFF)
# Set the interrupt polarity to be active high and mirroring disabled, so
# pins 1 to 8 trigger INT A and pins 9 to 16 trigger INT B
iobus.set_interrupt_polarity(1)
iobus.mirror_interrupts(0)
# Set the interrupts default value to 0x00 so the interrupt will trigger when any pin registers as true
iobus.set_interrupt_defaults(0, 0x00)
iobus.set_interrupt_defaults(1, 0x00)
# Set the interrupt type to be 1 for ports A and B so an interrupt is
# fired when the pin matches the default value
iobus.set_interrupt_type(0, 0xFF)
iobus.set_interrupt_type(1, 0xFF)
# Enable interrupts for all pins
iobus.set_interrupt_on_port(0, 0xFF)
iobus.set_interrupt_on_port(1, 0xFF)
while True:
# read the interrupt status for each port.
# If the status is not 0 then an interrupt has occured on one of the pins
# so read the value from the interrupt capture.
if (iobus.read_interrupt_status(0) != 0):
print("Port 0: " + str(iobus.read_interrupt_capture(0)))
if (iobus.read_interrupt_status(1) != 0):
print("Port 1: " + str(iobus.read_interrupt_capture(1)))
time.sleep(2)
def main():
'''
Main program function
'''
# Create an instance of the IOPi class with an I2C address of 0x20
iobus = IOPi(0x20)
# Set all pins on the IO bus to be inputs with internal pull-ups disabled.
iobus.set_port_pullups(0, 0x00)
iobus.set_port_pullups(1, 0x00)
iobus.set_port_direction(0, 0xFF)
iobus.set_port_direction(1, 0xFF)
# Set the interrupt polarity to be active high and mirroring disabled, so
# pins 1 to 8 trigger INT A and pins 9 to 16 trigger INT B
iobus.set_interrupt_polarity(1)
iobus.mirror_interrupts(0)
# Set the interrupts default value to trigger when 5V is applied to pins 1
# and 16
iobus.set_interrupt_defaults(0, 0x01)
iobus.set_interrupt_defaults(0, 0x80)
# Set the interrupt type to be 1 for ports A and B so an interrupt is
# fired when the pin matches the default value
iobus.set_interrupt_type(0, 1)
iobus.set_interrupt_type(1, 1)
# Enable interrupts for pins 1 and 16
iobus.set_interrupt_on_pin(1, 1)
iobus.set_interrupt_on_pin(16, 1)
while True:
# read the port value from the last capture for ports 0 and 1.
# This will reset the interrupts
print(iobus.read_interrupt_capture(0))
print(iobus.read_interrupt_capture(1))
time.sleep(2)
def main():
"""
Main program function
"""
# create two instances of the IoPi class called iobus1 and iobus2 and set
# the default i2c addresses
iobus1 = IOPi(0x20) # bus 1 will be inputs
iobus2 = IOPi(0x21) # bus 2 will be outputs
# Each bus is divided up two 8 bit ports. Port 0 controls pins 1 to 8,
# Port 1 controls pins 9 to 16.
# We will read the inputs on pin 1 of bus 1 so set port 0 to be inputs and
# enable the internal pull-up resistors
iobus1.set_port_direction(0, 0xFF)
iobus1.set_port_pullups(0, 0xFF)
# We will write to the output pin 1 on bus 2 so set port 0 to be outputs
# and turn off the pins on port 0
iobus2.set_port_direction(0, 0x00)
iobus2.write_port(0, 0x00)
while True:
# read pin 1 on bus 1. If pin 1 is high set the output on
# bus 2 pin 1 to high, otherwise set it to low.
# connect pin 1 on bus 1 to ground to see the output on
# bus 2 pin 1 change state.
if iobus1.read_pin(1) == 1:
iobus2.write_pin(1, 1)
else:
iobus2.write_pin(1, 0)
# wait 0.1 seconds before reading the pins again
time.sleep(0.1)
def main():
"""
Main program function
"""
iobus1 = IOPi(0x20)
iobus2 = IOPi(0x21)
# We will read the inputs 1 to 16 from the I/O bus so set port 0 and
# port 1 to be inputs and enable the internal pull-up resistors
iobus1.set_port_direction(0, 0xFF)
iobus1.set_port_pullups(0, 0xFF)
iobus1.set_port_direction(1, 0xFF)
iobus1.set_port_pullups(1, 0xFF)
# Repeat the steps above for the second bus
iobus2.set_port_direction(0, 0xFF)
iobus2.set_port_pullups(0, 0xFF)
iobus2.set_port_direction(1, 0xFF)
iobus2.set_port_pullups(1, 0xFF)
while True:
# clear the console
os.system("clear")
# read the pins 1 to 16 on both buses and print the results
print("Bus 1 Bus 2")
print("Pin 1: " + str(iobus1.read_pin(1)) +
" Pin 1: " + str(iobus2.read_pin(1)))
print("Pin 2: " + str(iobus1.read_pin(2)) +
" Pin 2: " + str(iobus2.read_pin(2)))
print("Pin 3: " + str(iobus1.read_pin(3)) +
" Pin 3: " + str(iobus2.read_pin(3)))
print("Pin 4: " + str(iobus1.read_pin(4)) +
" Pin 4: " + str(iobus2.read_pin(4)))
print("Pin 5: " + str(iobus1.read_pin(5)) +
" Pin 5: " + str(iobus2.read_pin(5)))
print("Pin 6: " + str(iobus1.read_pin(6)) +
" Pin 6: " + str(iobus2.read_pin(6)))
print("Pin 7: " + str(iobus1.read_pin(7)) +
" Pin 7: " + str(iobus2.read_pin(7)))
print("Pin 8: " + str(iobus1.read_pin(8)) +
" Pin 8: " + str(iobus2.read_pin(8)))
print("Pin 9: " + str(iobus1.read_pin(9)) +
" Pin 9: " + str(iobus2.read_pin(9)))
print("Pin 10: " + str(iobus1.read_pin(10)) +
" Pin 10: " + str(iobus2.read_pin(10)))
print("Pin 11: " + str(iobus1.read_pin(11)) +
" Pin 11: " + str(iobus2.read_pin(11)))
print("Pin 12: " + str(iobus1.read_pin(12)) +
" Pin 12: " + str(iobus2.read_pin(12)))
print("Pin 13: " + str(iobus1.read_pin(13)) +
" Pin 13: " + str(iobus2.read_pin(13)))
print("Pin 14: " + str(iobus1.read_pin(14)) +
" Pin 14: " + str(iobus2.read_pin(14)))
print("Pin 15: " + str(iobus1.read_pin(15)) +
" Pin 15: " + str(iobus2.read_pin(15)))
print("Pin 16: " + str(iobus1.read_pin(16)) +
" Pin 16: " + str(iobus2.read_pin(16)))
# wait 0.5 seconds before reading the pins again
time.sleep(0.1)
class Hardware:
"""
Hardware abstraction Class
"""
bus = None
def __init__(self, simulated):
"""
__init__ is called at startup
"""
self.simulatedHw = simulated
if self.simulatedHw:
self.doorStateUp = False
else:
# create an instance of Bus 1 which is on I2C address 0x21 by default
self.bus = IOPi(0x20)
# set pins 1 to 8 to be outputs and turn them off
self.bus.set_port_direction(0, 0x00)
self.bus.write_port(0, 0x00)
# set pins 9 to 16 to be inputs and turn pull-up on
self.bus.set_port_direction(1, 1)
self.bus.set_port_pullups(1, 1)
self.timeToMove = 20
if self.detect_door_down():
self.doorStateUp = False
elif self.detect_door_up():
self.doorStateUp = True
else:
# reboot while undetermined state -> close door
self.doorStateUp = True
self.motor_down()
def motor_stop(self):
"""
controls the H-bridge to stop the motor.
"""
if not self.simulatedHw:
# set all H-bridge switches to off
self.bus.write_pin(1, 0x00)
self.bus.write_pin(2, 0x00)
self.bus.write_pin(3, 0x00)
self.bus.write_pin(4, 0x00)
def motor_up(self):
"""
controls the H-bridge to move the motor in a specific direction.
"""
if not self.simulatedHw:
# avoid conflicts
self.motor_stop()
# enable up
self.bus.write_pin(1, 0x01)
self.bus.write_pin(3, 0x01)
time.sleep(self.timeToMove)
self.motor_stop()
self.doorStateUp = True
def motor_down(self):
"""
controls the H-bridge to move the motor in a specific direction.
"""
if not self.simulatedHw:
# avoid conflicts
self.motor_stop()
# enable downward side of H-bridge
self.bus.write_pin(1, 0x01)
self.bus.write_pin(2, 0x01)
time.sleep(self.timeToMove)
self.motor_stop()
self.doorStateUp = False
def button_pressed(self):
"""
checks if the button is pressed with debouncing.
"""
if self.simulatedHw:
return False
else:
pin = 9
if self.bus.read_pin(pin) == 0:
time.sleep(0.05)
if self.bus.read_pin(pin) == 0: # debounce 50 ms
return True
return False
def detect_door_down(self):
"""
checks if the door if completely at the down end stop
"""
if self.simulatedHw:
return True
else:
pin = 10
if self.bus.read_pin(pin) == 0:
time.sleep(0.05)
if self.bus.read_pin(pin) == 0: # debounce 50 ms
return True
return False
def detect_door_up(self):
"""
checks if the door if completely at the down end stop
"""
if self.simulatedHw:
return True
else:
pin = 11
if self.bus.read_pin(pin) == 0:
time.sleep(0.05)
if self.bus.read_pin(pin) == 0: # debounce 50 ms
return True
return False
def is_door_up(self):
"""
Returns the state of the door without checking the hardware to save detection time
"""
return self.doorStateUp
def main():
"""
Main program function
"""
iobus1 = IOPi(0x20)
iobus2 = IOPi(0x21)
# We will read the inputs 1 to 16 from the I/O bus so set port 0 and
# port 1 to be inputs and enable the internal pull-up resistors
iobus1.set_port_direction(0, 0xFF)
iobus1.set_port_pullups(0, 0xFF)
iobus1.set_port_direction(1, 0xFF)
iobus1.set_port_pullups(1, 0xFF)
# Repeat the steps above for the second bus
iobus2.set_port_direction(0, 0xFF)
iobus2.set_port_pullups(0, 0xFF)
iobus2.set_port_direction(1, 0xFF)
iobus2.set_port_pullups(1, 0xFF)
while True:
# clear the console
os.system("clear")
# read the pins 1 to 16 on both buses and print the results
print("Bus 1 Bus 2")
print("Pin 1: " + str(iobus1.read_pin(1)) +
" Pin 1: " + str(iobus2.read_pin(1)))
print("Pin 2: " + str(iobus1.read_pin(2)) +
" Pin 2: " + str(iobus2.read_pin(2)))
print("Pin 3: " + str(iobus1.read_pin(3)) +
" Pin 3: " + str(iobus2.read_pin(3)))
print("Pin 4: " + str(iobus1.read_pin(4)) +
" Pin 4: " + str(iobus2.read_pin(4)))
print("Pin 5: " + str(iobus1.read_pin(5)) +
" Pin 5: " + str(iobus2.read_pin(5)))
print("Pin 6: " + str(iobus1.read_pin(6)) +
" Pin 6: " + str(iobus2.read_pin(6)))
print("Pin 7: " + str(iobus1.read_pin(7)) +
" Pin 7: " + str(iobus2.read_pin(7)))
print("Pin 8: " + str(iobus1.read_pin(8)) +
" Pin 8: " + str(iobus2.read_pin(8)))
print("Pin 9: " + str(iobus1.read_pin(9)) +
" Pin 9: " + str(iobus2.read_pin(9)))
print("Pin 10: " + str(iobus1.read_pin(10)) +
" Pin 10: " + str(iobus2.read_pin(10)))
print("Pin 11: " + str(iobus1.read_pin(11)) +
" Pin 11: " + str(iobus2.read_pin(11)))
print("Pin 12: " + str(iobus1.read_pin(12)) +
" Pin 12: " + str(iobus2.read_pin(12)))
print("Pin 13: " + str(iobus1.read_pin(13)) +
" Pin 13: " + str(iobus2.read_pin(13)))
print("Pin 14: " + str(iobus1.read_pin(14)) +
" Pin 14: " + str(iobus2.read_pin(14)))
print("Pin 15: " + str(iobus1.read_pin(15)) +
" Pin 15: " + str(iobus2.read_pin(15)))
print("Pin 16: " + str(iobus1.read_pin(16)) +
" Pin 16: " + str(iobus2.read_pin(16)))
# wait 0.5 seconds before reading the pins again
time.sleep(0.1)
def main():
"""
Main program function
"""
passed = True
iopi = IOPi(0x20, False) # new iopi object without initialisation
iopi.set_bus_pullups(0x0000)
# Check set_port_pullups port for low out of bounds
try:
iopi.set_port_pullups(-1, 0)
pass
except ValueError:
print("port low boundary check: PASSED")
pass
except IOError:
passed = False
print("I2C IOError")
else:
passed = False
print("port low boundary check: FAILED")
pass
# Check set_port_pullups port for high out of bounds
try:
iopi.set_port_pullups(2, 0)
pass
except ValueError:
print("port high boundary check: PASSED")
pass
except IOError:
passed = False
print("I2C IOError")
else:
passed = False
print("port high boundary check: FAILED")
pass
# Check set_port_pullups value for low out of bounds
try:
iopi.set_port_pullups(0, -1)
pass
except ValueError:
print("value low boundary check: PASSED")
pass
except IOError:
passed = False
print("I2C IOError")
else:
passed = False
print("value low boundary check: FAILED")
pass
# Check set_port_pullups value for high out of bounds
try:
iopi.set_port_pullups(0, 256)
pass
except ValueError:
print("value high boundary check: PASSED")
pass
except IOError:
passed = False
print("I2C IOError")
else:
passed = False
print("value high boundary check: FAILED")
pass
# Logic Analyser Check
print("Logic output Started")
for x in range(0, 256):
iopi.set_port_pullups(0, x)
iopi.set_port_pullups(1, x)
print("Logic output Ended")
if passed is False:
print("Test Failed")
print("Importing from parent folder instead")
try:
import sys
sys.path.append('..')
from IOPi import IOPi
except ImportError:
raise ImportError("Failed to import library from parent folder")
# Setup IOPi I2C addresses
iobus1 = IOPi(0x20)
iobus2 = IOPi(0x21)
# We will read the inputs 1 to 16 from the I/O bus so set port 0 and
# port 1 to be inputs and enable the internal pull-up resistors
iobus1.set_port_direction(0, 0xFF)
iobus1.set_port_pullups(0, 0xFF)
iobus1.set_port_direction(1, 0xFF)
iobus1.set_port_pullups(1, 0xFF)
# Repeat the steps above for the second bus
iobus2.set_port_direction(0, 0xFF)
iobus2.set_port_pullups(0, 0xFF)
iobus2.set_port_direction(1, 0xFF)
iobus2.set_port_pullups(1, 0xFF)
############### MQTT section ##################
def on_connect(client, userdata, flags, rc):
class Hardware:
"""
Hardware abstraction Class
"""
bus = None
def __init__(self):
"""
__init__ is called at startup
"""
# create an instance of Bus 1 which is on I2C address 0x21 by default
self.bus = IOPi(0x20)
# set pins 1 to 8 to be outputs and turn them off
self.bus.set_port_direction(0, 0x00)
self.bus.write_port(0, 0x00)
# set pins 9 to 16 to be inputs and turn pullup on
self.bus.set_port_direction(1, 1)
self.bus.set_port_pullups(1, 1)
def motor_stop(self):
"""
controls the H-bridge to stop the motor.
"""
# set all H-bridge switches to off
self.bus.write_pin(1, 0x00)
self.bus.write_pin(2, 0x00)
self.bus.write_pin(3, 0x00)
self.bus.write_pin(4, 0x00)
def motor_up(self):
"""
controls the H-bridge to move the motor in a specific direction.
"""
# avoid conflicts
self.motor_stop()
# enable up
self.bus.write_pin(1, 0x01)
self.bus.write_pin(3, 0x01)
def motor_down(self):
"""
controls the H-bridge to move the motor in a specific direction.
"""
# avoid conflicts
self.motor_stop()
# enable downward sidecof H-bridge
self.bus.write_pin(1, 0x01)
self.bus.write_pin(2, 0x01)
def button_pressed(self):
"""
controls the H-bridge to move the motor in a specific direction.
"""
if self.read_pin(8) == 0:
time.sleep(0.05)
if self.read_pin(8) == 0: # debounce 50 ms
return True
return False
def main():
"""
Main program function
"""
global bus
# Create an instance of the IOPi class called bus and
# set the I2C address to be 0x20 or Bus 1.
bus = IOPi(0x20)
# Set port 0 on the bus to be inputs with internal pull-ups enabled.
bus.set_port_pullups(0, 0xFF)
bus.set_port_direction(0, 0xFF)
# Inverting the port will allow a button connected to ground to
# register as 1 or on.
bus.invert_port(0, 0xFF)
# Set the interrupt polarity to be active low so Int A and IntB go low
# when an interrupt is triggered and mirroring disabled, so
# Int A is mapped to port 0 and Int B is mapped to port 1
bus.set_interrupt_polarity(0)
bus.mirror_interrupts(0)
# Set the interrupts default value to 0 so it will trigger when any of
# the pins on the port 0 change to 1
bus.set_interrupt_defaults(0, 0x00)
# Set the interrupt type to be 0xFF so an interrupt is
# fired when the pin matches the default value
bus.set_interrupt_type(0, 0xFF)
# Enable interrupts for all pins on port 0
bus.set_interrupt_on_port(0, 0xFF)
# reset the interrups on the IO Pi bus
bus.reset_interrupts()
# set the Raspberry Pi GPIO mode to be BCM
GPIO.setmode(GPIO.BCM)
# Set up GPIO 23 as an input. The pull-up resistor is disabled as the
# level shifter will act as a pull-up.
GPIO.setup(23, GPIO.IN, pull_up_down=GPIO.PUD_OFF)
# when a falling edge is detected on GPIO 23 the function
# button_pressed will be run
GPIO.add_event_detect(23, GPIO.FALLING, callback=button_pressed)
# print out a message and wait for keyboard input before
# exiting the program
input("press enter to exit ")