#!/usr/bin/env python3
"""
Display values on input pins of a BitBangDevice.
TODO:
* ANSI colours / display differences in bold
example - beep on pin 1 going high:
$ pylibftdi/examples/pin_read.py -n 0.01 -m 1 -k 1 && beep
Copyright (c) 2011-2014 Ben Bass <benbass@codedstructure.net>
All rights reserved.
"""
import itertools
import sys
import time
from pylibftdi import ALL_INPUTS, BitBangDevice
[docs]def get_value():
"""
get the value of the pins
"""
if not getattr(get_value, "dev", None):
get_value.dev = BitBangDevice(direction=ALL_INPUTS)
dev = get_value.dev
return dev.port
[docs]def display_value(value):
"""
display the given value
"""
sys.stdout.write("\b" * 32)
for n in range(8):
sys.stdout.write("1 " if value & (1 << (7 - n)) else "0 ")
sys.stdout.write(" (%d/0x%02X)" % (value, value))
sys.stdout.flush()
[docs]def display_loop(interval=1, count=0, match=None, mask=0xFF):
"""
display and compare the value
:param interval: polling interval in seconds
:param count: number of polls to do, or infinite if 0
:param match: value to look for to exit early
:param mask: mask of read value before comparing to match
:return: 'ok'. either a match was made or none was requested
:rtype: bool
"""
if not count:
count_iter = itertools.count()
else:
count_iter = range(count)
try:
for _ in count_iter:
value = get_value()
display_value(value)
if match is not None and (value & mask == match):
return True
time.sleep(interval)
return False
except KeyboardInterrupt:
pass
finally:
sys.stdout.write("\n")
if match is not None:
# we quit early while looking for a match
return False
else:
# no match to do; no problem.
return True
[docs]def main(args=None):
import argparse
parser = argparse.ArgumentParser()
parser.add_argument(
"-n",
"--interval",
dest="interval",
default=1,
type=float,
help="refresh interval, default 1 second",
)
parser.add_argument(
"-c",
"--count",
dest="count",
default=0,
type=int,
help="number of cycles to run for (0 = no limit - the default)",
)
parser.add_argument(
"-m", "--match", dest="match", help="value to match against (e.g. 0x1F, 7, etc)"
)
parser.add_argument(
"-k",
"--mask",
dest="mask",
help="mask to match with (e.g. 0x07, 2, etc) - default 0xFF",
)
args = parser.parse_args(args)
if args.interval < 0.001:
parser.error("interval must be >= 0.001")
if args.count < 0:
parser.error("count must be >= 0")
mask = match = None
if args.mask:
if not args.match:
parser.error("Must specify --match with mask")
try:
mask = int(args.mask, 0)
except ValueError:
parser.error("Could not interpret given mask")
else:
mask = 0xFF
if args.match:
try:
match = int(args.match, 0)
except ValueError:
parser.error("Could not interpret given mask")
ok = display_loop(args.interval, args.count, match, mask)
sys.exit(0 if ok else 1)
if __name__ == "__main__":
main()