verlock-door-controller/wiegand.py
2022-03-11 19:59:01 +02:00

158 lines
4.9 KiB
Python

#!/bin/python
import logging
from time import sleep
try:
import pigpio
except Exception:
pigpio = False
class Decoder:
"""
A class to read Wiegand codes of an arbitrary length.
"""
def __init__(self, callback, bit_timeout=5):
"""
Instantiate with the pi, gpio for 0 (green wire), the gpio for 1
(white wire), the callback function, and the bit timeout in
milliseconds which indicates the end of a code.
The callback is passed the code length in bits and the hex value.
"""
if pigpio:
self.pi = pigpio.pi()
else:
self.pi = False
self.gpio_0 = 17
self.gpio_1 = 18
self.door_pin = 21
self.button_pin = 13
self.callback = callback
self.bit_timeout = bit_timeout
self.items = []
self.in_code = False
if self.pi:
self.pi.set_mode(self.gpio_0, pigpio.INPUT)
self.pi.set_mode(self.gpio_1, pigpio.INPUT)
self.pi.set_mode(self.door_pin, pigpio.OUTPUT)
self.pi.set_mode(self.button_pin, pigpio.INPUT)
self.pi.set_pull_up_down(self.gpio_0, pigpio.PUD_UP)
self.pi.set_pull_up_down(self.gpio_1, pigpio.PUD_UP)
self.pi.set_pull_up_down(self.button_pin, pigpio.PUD_UP)
self.cb_0 = self.pi.callback(self.gpio_0,
pigpio.FALLING_EDGE,
self._cb)
self.cb_1 = self.pi.callback(self.gpio_1,
pigpio.FALLING_EDGE,
self._cb)
self.button_cb_h = self.pi.callback(self.button_pin,
pigpio.FALLING_EDGE,
self._cb)
def cut_empty(self, item):
if item[0:8] == "00000000":
return self.cut_empty(item[8:])
else:
return item
def get_hex(self):
try:
items = self.items
if len(self.items) == 26:
items = self.items[1:-1]
elif len(self.items) == 64:
items = self.cut_empty(self.items)
bits = []
for i in range(len(items), 0, -8):
bits.append(int(items[i - 8:i], 2))
return (" ".join(map(lambda a: "%-0.2X" % ((a + 256) % 256),
bits))).rstrip()
except ValueError:
logging.error(f"Failed to convert binary to hex: {self.items}")
return False
except Exception as e:
logging.error(f"Wiegand convert error (raw: {self.items}): {e}")
return False
def _cb(self, gpio_pin, level, tick):
"""
Accumulate bits until both gpios 0 and 1 timeout.
"""
try:
if level < pigpio.TIMEOUT:
if self.in_code:
self.bits += 1
else:
logging.debug(f"Wiegand data transfer start")
self.bits = 1
self.items = ""
self.in_code = True
self.code_timeout = 0
self.pi.set_watchdog(self.gpio_0, self.bit_timeout)
self.pi.set_watchdog(self.gpio_1, self.bit_timeout)
if gpio_pin == self.gpio_0:
self.code_timeout &= 2
self.items += "1"
else:
self.code_timeout &= 1
self.items += "0"
else:
if self.in_code:
if gpio_pin == self.gpio_0:
self.code_timeout |= 1 # timeout gpio 0
else:
self.code_timeout |= 2 # timeout gpio 1
if self.code_timeout == 3: # both gpios timed out
self.pi.set_watchdog(self.gpio_0, 0)
self.pi.set_watchdog(self.gpio_1, 0)
self.in_code = False
if self.bits >= 26:
hex = self.get_hex()
if hex:
self.callback(hex)
else:
logging.error(f"Expected 26 bits, but got {self.bits:d}: {self.items}")
except Exception as e:
logging.error(f"Wiegand callback error: {e}")
def button_cb(self, gpio_pin, level, tick):
print(f"button: gpio_pin:{gpio_pin}, level:{level}, tick:{tick}")
def open_door(self):
self.pi.write(self.door_pin, 1)
sleep(3)
self.pi.write(self.door_pin, 0)
def cancel(self):
"""
Cancel the Wiegand decoder.
"""
self.cb_0.cancel()
self.cb_1.cancel()
self.button_cb_h.cancel()
self.pi.stop()