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Description:

raspihats 2.4.0

raspihats package
This python package provides the necessary code to interface the Raspberry Pi add-on boards from raspihats.com:
Typical usage often looks like this:
#!/usr/bin/env python
# In this setup there are two I2C-HATs stacked, one DI16ac and one DQ10rly.
from raspihats.i2c_hats import DI16ac, DQ10rly

di16ac = DI16ac(0x40) # 0x40 is the I2C bus address
dq10rly = DQ10rly(0x50) # 0x50 is the I2C bus address

while True:
state = di16ac.di.channels[0] # get digital input channel 0
dq10rly.dq.channels[0] = state # set digital output channel 0
dq10rly.dq.channels[1] = not state # set digital output channel 1

IRQ feature(from v2.3.0)

Starting from hardware revision 2.0, DI16ac I2C-HAT and DI6acDQ6rly I2C-HAT can trigger an IRQ line that's connected to GPIO21 of the Raspberry Pi.

try:
import Queue as queue
except ImportError:
import queue
from time import sleep
import RPi.GPIO as GPIO
from raspihats.i2c_hats import DI16ac, DI6acDQ6rly

IRQ_PIN = 21
GPIO.setmode(GPIO.BCM)

# IRQ pin setup as input with pull-up enabled
GPIO.setup(IRQ_PIN, GPIO.IN, pull_up_down=GPIO.PUD_UP)

# this queue is used to safely exchange information between threads
event_queue = queue.Queue(maxsize = 20)

def isr(pin):
event_queue.put(pin)

GPIO.add_event_detect(IRQ_PIN, GPIO.FALLING, callback=isr)

# b = DI16ac(0x40) # 0x40 is the I2C bus address
b = DI6acDQ6rly(0x60) # 0x60 is the I2C bus address

print(str(b.name) + ' ' + str(b.fw_version))
print('Use Ctrl+C to stop program.')

# enable rising edge IRQs for Digital Input channels 0 and 2
b.di.irq_reg.rising_edge_control = 0x05

# enable falling edge IRQs for Digital Input channels 1 and 2
b.di.irq_reg.falling_edge_control = 0x06

# dump DigitalInputs IRQ CaptureQueue contents and release IRQ line by
# writing 0 to DigitalInputs IRQ Capture Register
b.di.irq_reg.capture = 0

while True:
try:
# wait until there is something in the queue, timeout is here because a
# queue.get without a timeout can't be interrupted with a KeyboardInterrupt
pin = event_queue.get(block=True, timeout=0.2)
if pin == IRQ_PIN:
# read the DigitalInputs IRQ Capture Register(to read the values
# stored in the DigitalInputs IRQ CaptureQueue) until the
# returned value is 0, this means DigitalInputs IRQ CaptureQueue
# is empty and the IRQ line is released
while True:
capture = b.di.irq_reg.capture
if capture == 0:
break
status = capture & 0xFFFF
states = (capture >> 16) & 0xFFFF
for channel in range(0, 16):
mask = 0x01 << channel
if (status & mask) > 0:
print('IRQ detected on channel: %d, state: %d' %(channel, (states & mask) >> channel))
except queue.Empty:
pass

except KeyboardInterrupt:
# disable rising edge IRQs for Digital Input channels
b.di.irq_reg.rising_edge_control = 0

# disable falling edge IRQs for Digital Input channels
b.di.irq_reg.falling_edge_control = 0

GPIO.remove_event_detect(IRQ_PIN)
GPIO.cleanup()

break

Listing attributes and methods(from v2.0.0)
from raspihats.i2c_hats import DI6acDQ6rly

board = DI6acDQ6rly(0x60) # 0x60 is the I2C bus address

board.name # get board name, in this case 'DI6acDQ6rly'
board.status.value # get status word
board.reset() # reset board

# cwdt - Communication WatchDog Timer
board.cwdt.period # get CommunicationWatchDogTimer(CWDT) period
board.cwdt.period = 1 # set CWDT period, any value greather than 0 enables the CWDT
board.cwdt.period = 0 # 0 disables the CWDT

# di - Digital Inputs
board.di.value # get all digital input channel states, bit 0 represents channel 0 state and so on ..
board.di.channels[0] # get digital input channel 0 state, access using channel index
board.di.channels['I0'] # get digital input channel 0 state, access using channel label
board.di.r_counters[0] # get digital input channel 0 rising edge counter
board.di.r_counters['I0'] # get digital input channel 0 rising edge counter
board.di.r_counters[0] = 0 # reset digital input channel 0 rising edge counter
board.di.r_counters['I0'] = 0 # reset digital input channel 0 rising edge counter
board.di.f_counters[0] # get digital input channel 0 falling edge counter
board.di.f_counters['I0'] # get digital input channel 0 falling edge counter
board.di.f_counters[0] = 0 # reset digital input channel 0 falling edge counter
board.di.f_counters['I0'] = 0 # reset digital input channel 0 falling edge counter
board.di.reset_counters() # reset all counters(rising and falling edge) for all channels
board.di.labels # get digital input labels

# dq - Digital Outputs
board.dq.value # get all digital output channel states, bit 0 represents channel 0 and so on ..
board.dq.value = 0 # set all digital output channel states
board.dq.channels[0] # get digital output channel 0 state, access using channel index
board.dq.channels[0] = 0 # set digital output channel 0 state
board.dq.channels['Q0'] # get digital output channel 0 state, access using channel label
board.dq.channels['Q0'] = 0 # set digital output channel 0 state
# PowerOnValue -- loaded to Digital Outputs at board power on
board.dq.power_on_value # get digital output channels PowerOnValue, bit 0 represents channel 0 and so on ..
board.dq.power_on_value = 0 # set digital output channels PowerOnValue
# SafetyValue -- loaded to Digital Outputs at CWDT timeout
board.dq.safety_value # get digital output channels SafetyValue, bit 0 represents channel 0 and so on ..
board.dq.safety_value = 0 # set digital output channels SafetyValue
board.dq.labels # get digital output labels

Change Log
v2.4.0

Switched to smbus2 to communicate over I2C
Removed I2C clock stretching timeout script, RaspberryPi OS sets by default an acceptable value for the I2C clock stretching timeout.
Added support for new boards:

DI6acDQ6ssr I2C-HAT
DI6dwDQ6ssr I2C-HAT

v2.3.0

Added IRQ support

v2.2.3

enum34 is loaded for python<3.4
Setup script warning if it's not run with sudo(used to setup I2C ClockStretchTimeout)

v2.2.2

Bug fix in setup script, BCM2835 platform hardware is now recognized.
Bug fix in robotframework interface, status.value is now returned by get_status()

v2.2.1

Added StatusWord class. To get raw int value use board.status.value, to get beautiful string representation use str(board.status).

v2.1.1

String representation of I2CHat object doesn't use an I2C bus transfer any more.
Improved exception messages

v2.1.0

Improved exception handling

v2.0.1

Fixed I2C clock stretch timeout setup script

v2.0.0

Attributes are now used for accessing board parameters, rather then methods
Added support for new boards:

DI16ac I2C-HAT (replacement for Di16 I2C-HAT)
DQ10rly I2C-HAT (replacement for Rly10 I2C-HAT)
DQ16oc I2C-HAT
DI6acDQ6rly I2C-HAT (replacement for Di6Rly6 I2C-HAT)

v1.1.1

Added support for new boards:

Di16
Rly10
Di6Rly6

Installation
$ pip install raspihats

Checkout raspihats.com!