On Sun, 19 Aug 2018 19:53:04 +1000
Cameron Simpson <c...@cskk.id.au> wrote:
[Oops, apparently you set the Reply-To to python-list@python.org,
normally that's no problem, but I did something wrong somewhere]
> There are always unPythonic bits. Even after you've cleaned them all
> up, since people will disagree about the finer points of Pythonicism
> there will be bits both over and under cleaned.
Although I do not understand exactly what zip is doing here (I presume
I switch to use pointers instead of the values), I like the
"enumerate" function, very handy :-) The code is now as
follows:
#!/usr/bin/env python3
import sys
from smbus import SMBus
from time import sleep
import RPi.GPIO as GPIO
list_pcf = [0x38, 0x39, 0x3a, 0x3b]
list_pcf_value = []
GPIO.setmode(GPIO.BCM)
bus = SMBus(1)
# initialisation of the input devices:
print ("[INFO] initialisation input devices")
for pcf in list_pcf:
try:
bus.write_byte(pcf, 0xff) # set device to 0xff
except IOError as e:
print ("[ALERT] I/O problem device 0x%x (init): %s" % (pcf, e))
output = bus.read_byte(pcf)
list_pcf_value.append(output) # append value to list
print ("found pcf8574 at 0x%x, input value: 0x%x" % (pcf, output))
sys.stdout.flush()
# GPIO 23 set up as input. It is pulled up to stop false signals
GPIO.setup(23, GPIO.IN, pull_up_down=GPIO.PUD_UP)
loopcntr = 0 # detects if INT is kept low
while True:
if GPIO.input(23) == 1: # if still 0, another event has occurred
GPIO.wait_for_edge(23, GPIO.FALLING)
while GPIO.input(23) == 0:
for device_nr, (pcf, pcf_value) in enumerate(zip(list_pcf, list_pcf_value)):
try:
output = bus.read_byte(pcf)
except IOError as e:
print ("[ALERT] I/O problem device 0x%x: %s" % (pcf, e))
if output != pcf_value:
xor = pcf_value ^ output
for bit_pos in range(8):
if xor & 0x1:
up_down = (output >> bit_pos) & 0x1
print ("pcf8574 0x%x bit %d: to %d" % (pcf,bit_pos,up_down))
# send decimal values to event script:
with open('/mnt/ramdisk/var/lib/ha/events.fifo', 'w') as fifo:
print("%d %d %d" % (pcf,bit_pos,up_down), file=fifo)
xor >>= 1
list_pcf_value[device_nr] = output
if GPIO.input(23) == 1:
loopcntr = 0
break
loopcntr += 1
if loopcntr >=20:
print ('[ALERT] possible INT loop, disabling 10 seconds')
sys.stdout.flush()
sleep (10)
sys.stdout.flush()
GPIO.cleanup()
And it still works :-)
Thnx!
R.
--
richard lucassen
http://contact.xaq.nl/
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