wiegand.py
Go to the documentation of this file.
00001 #!/usr/bin/env python
00002 
00003 import pigpio
00004 
00005 class decoder:
00006 
00007    """
00008    A class to read Wiegand codes of an arbitrary length.
00009 
00010    The code length and value are returned.
00011 
00012    EXAMPLE
00013 
00014    #!/usr/bin/env python
00015 
00016    import time
00017 
00018    import pigpio
00019 
00020    import wiegand
00021 
00022    def callback(bits, code):
00023       print("bits={} code={}".format(bits, code))
00024 
00025    pi = pigpio.pi()
00026 
00027    w = wiegand.decoder(pi, 14, 15, callback)
00028 
00029    time.sleep(300)
00030 
00031    w.cancel()
00032 
00033    pi.stop()
00034    """
00035 
00036    def __init__(self, pi, gpio_0, gpio_1, callback, bit_timeout=5):
00037 
00038       """
00039       Instantiate with the pi, gpio for 0 (green wire), the gpio for 1
00040       (white wire), the callback function, and the bit timeout in
00041       milliseconds which indicates the end of a code.
00042 
00043       The callback is passed the code length in bits and the value.
00044       """
00045 
00046       self.pi = pi
00047       self.gpio_0 = gpio_0
00048       self.gpio_1 = gpio_1
00049 
00050       self.callback = callback
00051 
00052       self.bit_timeout = bit_timeout
00053 
00054       self.in_code = False
00055 
00056       self.pi.set_mode(gpio_0, pigpio.INPUT)
00057       self.pi.set_mode(gpio_1, pigpio.INPUT)
00058 
00059       self.pi.set_pull_up_down(gpio_0, pigpio.PUD_UP)
00060       self.pi.set_pull_up_down(gpio_1, pigpio.PUD_UP)
00061 
00062       self.cb_0 = self.pi.callback(gpio_0, pigpio.FALLING_EDGE, self._cb)
00063       self.cb_1 = self.pi.callback(gpio_1, pigpio.FALLING_EDGE, self._cb)
00064 
00065    def _cb(self, gpio, level, tick):
00066 
00067       """
00068       Accumulate bits until both gpios 0 and 1 timeout.
00069       """
00070 
00071       if level < pigpio.TIMEOUT:
00072 
00073          if self.in_code == False:
00074             self.bits = 1
00075             self.num = 0
00076 
00077             self.in_code = True
00078             self.code_timeout = 0
00079             self.pi.set_watchdog(self.gpio_0, self.bit_timeout)
00080             self.pi.set_watchdog(self.gpio_1, self.bit_timeout)
00081          else:
00082             self.bits += 1
00083             self.num = self.num << 1
00084 
00085          if gpio == self.gpio_0:
00086             self.code_timeout = self.code_timeout & 2 # clear gpio 0 timeout
00087          else:
00088             self.code_timeout = self.code_timeout & 1 # clear gpio 1 timeout
00089             self.num = self.num | 1
00090 
00091       else:
00092 
00093          if self.in_code:
00094 
00095             if gpio == self.gpio_0:
00096                self.code_timeout = self.code_timeout | 1 # timeout gpio 0
00097             else:
00098                self.code_timeout = self.code_timeout | 2 # timeout gpio 1
00099 
00100             if self.code_timeout == 3: # both gpios timed out
00101                self.pi.set_watchdog(self.gpio_0, 0)
00102                self.pi.set_watchdog(self.gpio_1, 0)
00103                self.in_code = False
00104                self.callback(self.bits, self.num)
00105 
00106    def cancel(self):
00107 
00108       """
00109       Cancel the Wiegand decoder.
00110       """
00111 
00112       self.cb_0.cancel()
00113       self.cb_1.cancel()
00114 
00115 if __name__ == "__main__":
00116 
00117    import time
00118 
00119    import pigpio
00120 
00121    import wiegand
00122 
00123    def callback(bits, value):
00124       print("bits={} value={}".format(bits, value))
00125 
00126    pi = pigpio.pi()
00127 
00128    w = wiegand.decoder(pi, 14, 15, callback)
00129 
00130    time.sleep(300)
00131 
00132    w.cancel()
00133 
00134    pi.stop()
00135 


cob_hand_bridge
Author(s): Mathias L├╝dtke
autogenerated on Thu Jun 6 2019 20:43:57