+++ /dev/null
-##
-## This file is part of the sigrok project.
-##
-## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
-##
-## This program is free software; you can redistribute it and/or modify
-## it under the terms of the GNU General Public License as published by
-## the Free Software Foundation; either version 2 of the License, or
-## (at your option) any later version.
-##
-## This program is distributed in the hope that it will be useful,
-## but WITHOUT ANY WARRANTY; without even the implied warranty of
-## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-## GNU General Public License for more details.
-##
-## You should have received a copy of the GNU General Public License
-## along with this program; if not, write to the Free Software
-## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
-##
-
-# DCF77 protocol decoder
-
-import sigrokdecode as srd
-import calendar
-
-# Return the specified BCD number (max. 8 bits) as integer.
-def bcd2int(b):
- return (b & 0x0f) + ((b >> 4) * 10)
-
-class Decoder(srd.Decoder):
- api_version = 1
- id = 'dcf77'
- name = 'DCF77'
- longname = 'DCF77 time protocol'
- desc = 'European longwave time signal (77.5kHz carrier signal).'
- license = 'gplv2+'
- inputs = ['logic']
- outputs = ['dcf77']
- probes = [
- {'id': 'data', 'name': 'DATA', 'desc': 'DATA line'},
- ]
- optional_probes = [
- {'id': 'pon', 'name': 'PON', 'desc': 'Power on'},
- ]
- options = {}
- annotations = [
- ['Text', 'Human-readable text'],
- ['Warnings', 'Human-readable warnings'],
- ]
-
- def __init__(self, **kwargs):
- self.state = 'WAIT FOR RISING EDGE'
- self.oldpins = None
- self.oldval = None
- self.oldpon = None
- self.samplenum = 0
- self.bit_start = 0
- self.bit_start_old = 0
- self.bitcount = 0 # Counter for the DCF77 bits (0..58)
- self.dcf77_bitnumber_is_known = 0
-
- def start(self, metadata):
- self.samplerate = metadata['samplerate']
- # self.out_proto = self.add(srd.OUTPUT_PROTO, 'dcf77')
- self.out_ann = self.add(srd.OUTPUT_ANN, 'dcf77')
-
- def report(self):
- pass
-
- # TODO: Which range to use? Only the 100ms/200ms or full second?
- def handle_dcf77_bit(self, bit):
- c = self.bitcount
- a = self.out_ann
- ss = es = 0 # FIXME
-
- # Create one annotation for each DCF77 bit (containing the 0/1 value).
- # Use 'Unknown DCF77 bit x: val' if we're not sure yet which of the
- # 0..58 bits it is (because we haven't seen a 'new minute' marker yet).
- # Otherwise, use 'DCF77 bit x: val'.
- s = '' if self.dcf77_bitnumber_is_known else 'Unknown '
- self.put(ss, es, a, [0, ['%sDCF77 bit %d: %d' % (s, c, bit)]])
-
- # If we're not sure yet which of the 0..58 DCF77 bits we have, return.
- # We don't want to decode bogus data.
- if not self.dcf77_bitnumber_is_known:
- return
-
- # Output specific "decoded" annotations for the respective DCF77 bits.
- if c == 0:
- # Start of minute: DCF bit 0.
- if bit == 0:
- self.put(ss, es, a, [0, ['Start of minute (always 0)']])
- else:
- self.put(ss, es, a, [0, ['ERROR: Start of minute != 0']])
- elif c in range(1, 14 + 1):
- # Special bits (civil warnings, weather forecast): DCF77 bits 1-14.
- if c == 1:
- self.tmp = bit
- else:
- self.tmp |= (bit << (c - 1))
- if c == 14:
- self.put(ss, es, a, [0, ['Special bits: %s' % bin(self.tmp)]])
- elif c == 15:
- s = '' if (bit == 1) else 'not '
- self.put(ss, es, a, [0, ['Call bit is %sset' % s]])
- # TODO: Previously this bit indicated use of the backup antenna.
- elif c == 16:
- s = '' if (bit == 1) else 'not '
- self.put(ss, es, a, [0, ['Summer time announcement %sactive' % s]])
- elif c == 17:
- s = '' if (bit == 1) else 'not '
- self.put(ss, es, a, [0, ['CEST is %sin effect' % s]])
- elif c == 18:
- s = '' if (bit == 1) else 'not '
- self.put(ss, es, a, [0, ['CET is %sin effect' % s]])
- elif c == 19:
- s = '' if (bit == 1) else 'not '
- self.put(ss, es, a, [0, ['Leap second announcement %sactive' % s]])
- elif c == 20:
- # Start of encoded time: DCF bit 20.
- if bit == 1:
- self.put(ss, es, a, [0, ['Start of encoded time (always 1)']])
- else:
- self.put(ss, es, a,
- [0, ['ERROR: Start of encoded time != 1']])
- elif c in range(21, 27 + 1):
- # Minutes (0-59): DCF77 bits 21-27 (BCD format).
- if c == 21:
- self.tmp = bit
- else:
- self.tmp |= (bit << (c - 21))
- if c == 27:
- self.put(ss, es, a, [0, ['Minutes: %d' % bcd2int(self.tmp)]])
- elif c == 28:
- # Even parity over minute bits (21-28): DCF77 bit 28.
- self.tmp |= (bit << (c - 21))
- parity = bin(self.tmp).count('1')
- s = 'OK' if ((parity % 2) == 0) else 'INVALID!'
- self.put(ss, es, a, [0, ['Minute parity: %s' % s]])
- elif c in range(29, 34 + 1):
- # Hours (0-23): DCF77 bits 29-34 (BCD format).
- if c == 29:
- self.tmp = bit
- else:
- self.tmp |= (bit << (c - 29))
- if c == 34:
- self.put(ss, es, a, [0, ['Hours: %d' % bcd2int(self.tmp)]])
- elif c == 35:
- # Even parity over hour bits (29-35): DCF77 bit 35.
- self.tmp |= (bit << (c - 29))
- parity = bin(self.tmp).count('1')
- s = 'OK' if ((parity % 2) == 0) else 'INVALID!'
- self.put(ss, es, a, [0, ['Hour parity: %s' % s]])
- elif c in range(36, 41 + 1):
- # Day of month (1-31): DCF77 bits 36-41 (BCD format).
- if c == 36:
- self.tmp = bit
- else:
- self.tmp |= (bit << (c - 36))
- if c == 41:
- self.put(ss, es, a, [0, ['Day: %d' % bcd2int(self.tmp)]])
- elif c in range(42, 44 + 1):
- # Day of week (1-7): DCF77 bits 42-44 (BCD format).
- # A value of 1 means Monday, 7 means Sunday.
- if c == 42:
- self.tmp = bit
- else:
- self.tmp |= (bit << (c - 42))
- if c == 44:
- d = bcd2int(self.tmp)
- dn = calendar.day_name[d - 1] # day_name[0] == Monday
- self.put(ss, es, a, [0, ['Day of week: %d (%s)' % (d, dn)]])
- elif c in range(45, 49 + 1):
- # Month (1-12): DCF77 bits 45-49 (BCD format).
- if c == 45:
- self.tmp = bit
- else:
- self.tmp |= (bit << (c - 45))
- if c == 49:
- m = bcd2int(self.tmp)
- mn = calendar.month_name[m] # month_name[1] == January
- self.put(ss, es, a, [0, ['Month: %d (%s)' % (m, mn)]])
- elif c in range(50, 57 + 1):
- # Year (0-99): DCF77 bits 50-57 (BCD format).
- if c == 50:
- self.tmp = bit
- else:
- self.tmp |= (bit << (c - 50))
- if c == 57:
- self.put(ss, es, a, [0, ['Year: %d' % bcd2int(self.tmp)]])
- elif c == 58:
- # Even parity over date bits (36-58): DCF77 bit 58.
- self.tmp |= (bit << (c - 50))
- parity = bin(self.tmp).count('1')
- s = 'OK' if ((parity % 2) == 0) else 'INVALID!'
- self.put(ss, es, a, [0, ['Date parity: %s' % s]])
- else:
- raise Exception('Invalid DCF77 bit: %d' % c)
-
- def decode(self, ss, es, data):
- for (self.samplenum, pins) in data:
-
- # Ignore identical samples early on (for performance reasons).
- if self.oldpins == pins:
- continue
- self.oldpins, (val, pon) = pins, pins
-
- # Always remember the old PON state.
- if self.oldpon != pon:
- self.oldpon = pon
-
- # Warn if PON goes low.
- if self.oldpon == 1 and pon == 0:
- self.pon_ss = self.samplenum
- self.put(self.samplenum, self.samplenum, self.out_ann,
- [1, ['Warning: PON goes low, DCF77 reception '
- 'no longer possible']])
- elif self.oldpon == 0 and pon == 1:
- self.put(self.samplenum, self.samplenum, self.out_ann,
- [0, ['PON goes high, DCF77 reception now possible']])
- self.put(self.pon_ss, self.samplenum, self.out_ann,
- [1, ['Warning: PON low, DCF77 reception disabled']])
-
- # Ignore samples where PON == 0, they can't contain DCF77 signals.
- if pon == 0:
- continue
-
- if self.state == 'WAIT FOR RISING EDGE':
- # Wait until the next rising edge occurs.
- if not (self.oldval == 0 and val == 1):
- self.oldval = val
- continue
-
- # Save the sample number where the DCF77 bit begins.
- self.bit_start = self.samplenum
-
- # Calculate the length (in ms) between two rising edges.
- len_edges = self.bit_start - self.bit_start_old
- len_edges_ms = int((len_edges / self.samplerate) * 1000)
-
- # The time between two rising edges is usually around 1000ms.
- # For DCF77 bit 59, there is no rising edge at all, i.e. the
- # time between DCF77 bit 59 and DCF77 bit 0 (of the next
- # minute) is around 2000ms. Thus, if we see an edge with a
- # 2000ms distance to the last one, this edge marks the
- # beginning of a new minute (and DCF77 bit 0 of that minute).
- if len_edges_ms in range(1600, 2400 + 1):
- self.put(ss, es, self.out_ann, [0, ['New minute starts']])
- self.bitcount = 0
- self.bit_start_old = self.bit_start
- self.dcf77_bitnumber_is_known = 1
- # Don't switch to 'GET BIT' state this time.
- continue
-
- self.bit_start_old = self.bit_start
- self.state = 'GET BIT'
-
- elif self.state == 'GET BIT':
- # Wait until the next falling edge occurs.
- if not (self.oldval == 1 and val == 0):
- self.oldval = val
- continue
-
- # Calculate the length (in ms) of the current high period.
- len_high = self.samplenum - self.bit_start
- len_high_ms = int((len_high / self.samplerate) * 1000)
-
- # If the high signal was 100ms long, that encodes a 0 bit.
- # If it was 200ms long, that encodes a 1 bit.
- if len_high_ms in range(40, 160 + 1):
- bit = 0
- elif len_high_ms in range(161, 260 + 1):
- bit = 1
- else:
- bit = -1 # TODO: Error?
-
- # There's no bit 59, make sure none is decoded.
- if bit in (0, 1) and self.bitcount in range(0, 58 + 1):
- self.handle_dcf77_bit(bit)
- self.bitcount += 1
-
- self.state = 'WAIT FOR RISING EDGE'
-
- else:
- raise Exception('Invalid state: %d' % self.state)
-
- self.oldval = val
-
projects / libsigrokdecode.git / blobdiff