[libsigrokdecode.git] / decoders / dcf77 / dcf77.py

##
## 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
Commit	Line	Data
2b0915c1 UH	1	##
	2	## This file is part of the sigrok project.
	3	##
	4	## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
	5	##
	6	## This program is free software; you can redistribute it and/or modify
	7	## it under the terms of the GNU General Public License as published by
	8	## the Free Software Foundation; either version 2 of the License, or
	9	## (at your option) any later version.
	10	##
	11	## This program is distributed in the hope that it will be useful,
	12	## but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	## GNU General Public License for more details.
	15	##
	16	## You should have received a copy of the GNU General Public License
	17	## along with this program; if not, write to the Free Software
	18	## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	19	##
	20
2b0915c1	21	# DCF77 protocol decoder
2b0915c1 UH	22
	23	import sigrokdecode as srd
	24	import calendar
	25
2b0915c1 UH	26	# Return the specified BCD number (max. 8 bits) as integer.
	27	def bcd2int(b):
	28	return (b & 0x0f) + ((b >> 4) * 10)
	29
	30	class Decoder(srd.Decoder):
a2c2afd9	31	api_version = 1
2b0915c1 UH	32	id = 'dcf77'
2b0915c1 UH	33	name = 'DCF77'
3d3da57d	34	longname = 'DCF77 time protocol'
a465436e	35	desc = 'European longwave time signal (77.5kHz carrier signal).'
2b0915c1 UH	36	license = 'gplv2+'
	37	inputs = ['logic']
	38	outputs = ['dcf77']
	39	probes = [
	40	{'id': 'data', 'name': 'DATA', 'desc': 'DATA line'},
	41	]
b77614bc	42	optional_probes = [
fcd8c14d	43	{'id': 'pon', 'name': 'PON', 'desc': 'Power on'},
decde15e	44	]
2b0915c1 UH	45	options = {}
2b0915c1 UH	46	annotations = [
ee3e279c	47	['Text', 'Human-readable text'],
fcd8c14d	48	['Warnings', 'Human-readable warnings'],
2b0915c1 UH	49	]
	50
	51	def __init__(self, **kwargs):
2b716038	52	self.state = 'WAIT FOR RISING EDGE'
2fcd7c22	53	self.oldpins = None
2b0915c1	54	self.oldval = None
fcd8c14d	55	self.oldpon = None
2b0915c1 UH	56	self.samplenum = 0
	57	self.bit_start = 0
	58	self.bit_start_old = 0
	59	self.bitcount = 0 # Counter for the DCF77 bits (0..58)
	60	self.dcf77_bitnumber_is_known = 0
	61
	62	def start(self, metadata):
	63	self.samplerate = metadata['samplerate']
	64	# self.out_proto = self.add(srd.OUTPUT_PROTO, 'dcf77')
	65	self.out_ann = self.add(srd.OUTPUT_ANN, 'dcf77')
	66
	67	def report(self):
	68	pass
	69
	70	# TODO: Which range to use? Only the 100ms/200ms or full second?
	71	def handle_dcf77_bit(self, bit):
	72	c = self.bitcount
	73	a = self.out_ann
	74	ss = es = 0 # FIXME
	75
	76	# Create one annotation for each DCF77 bit (containing the 0/1 value).
	77	# Use 'Unknown DCF77 bit x: val' if we're not sure yet which of the
	78	# 0..58 bits it is (because we haven't seen a 'new minute' marker yet).
	79	# Otherwise, use 'DCF77 bit x: val'.
	80	s = '' if self.dcf77_bitnumber_is_known else 'Unknown '
	81	self.put(ss, es, a, [0, ['%sDCF77 bit %d: %d' % (s, c, bit)]])
	82
	83	# If we're not sure yet which of the 0..58 DCF77 bits we have, return.
	84	# We don't want to decode bogus data.
	85	if not self.dcf77_bitnumber_is_known:
	86	return
	87
	88	# Output specific "decoded" annotations for the respective DCF77 bits.
	89	if c == 0:
	90	# Start of minute: DCF bit 0.
	91	if bit == 0:
	92	self.put(ss, es, a, [0, ['Start of minute (always 0)']])
	93	else:
	94	self.put(ss, es, a, [0, ['ERROR: Start of minute != 0']])
	95	elif c in range(1, 14 + 1):
	96	# Special bits (civil warnings, weather forecast): DCF77 bits 1-14.
	97	if c == 1:
	98	self.tmp = bit
	99	else:
	100	self.tmp \|= (bit << (c - 1))
	101	if c == 14:
	102	self.put(ss, es, a, [0, ['Special bits: %s' % bin(self.tmp)]])
	103	elif c == 15:
	104	s = '' if (bit == 1) else 'not '
	105	self.put(ss, es, a, [0, ['Call bit is %sset' % s]])
	106	# TODO: Previously this bit indicated use of the backup antenna.
	107	elif c == 16:
	108	s = '' if (bit == 1) else 'not '
	109	self.put(ss, es, a, [0, ['Summer time announcement %sactive' % s]])
	110	elif c == 17:
	111	s = '' if (bit == 1) else 'not '
	112	self.put(ss, es, a, [0, ['CEST is %sin effect' % s]])
	113	elif c == 18:
	114	s = '' if (bit == 1) else 'not '
	115	self.put(ss, es, a, [0, ['CET is %sin effect' % s]])
	116	elif c == 19:
	117	s = '' if (bit == 1) else 'not '
	118	self.put(ss, es, a, [0, ['Leap second announcement %sactive' % s]])
	119	elif c == 20:
120	# Start of encoded time: DCF bit 20.
121	if bit == 1:
122	self.put(ss, es, a, [0, ['Start of encoded time (always 1)']])
123	else:
124	self.put(ss, es, a,
125	[0, ['ERROR: Start of encoded time != 1']])
126	elif c in range(21, 27 + 1):
127	# Minutes (0-59): DCF77 bits 21-27 (BCD format).
128	if c == 21:
129	self.tmp = bit
130	else:
131	self.tmp \|= (bit << (c - 21))
132	if c == 27:
133	self.put(ss, es, a, [0, ['Minutes: %d' % bcd2int(self.tmp)]])
134	elif c == 28:
135	# Even parity over minute bits (21-28): DCF77 bit 28.
136	self.tmp \|= (bit << (c - 21))
137	parity = bin(self.tmp).count('1')
138	s = 'OK' if ((parity % 2) == 0) else 'INVALID!'
139	self.put(ss, es, a, [0, ['Minute parity: %s' % s]])
140	elif c in range(29, 34 + 1):
141	# Hours (0-23): DCF77 bits 29-34 (BCD format).
142	if c == 29:
143	self.tmp = bit
144	else:
145	self.tmp \|= (bit << (c - 29))
146	if c == 34:
147	self.put(ss, es, a, [0, ['Hours: %d' % bcd2int(self.tmp)]])
148	elif c == 35:
149	# Even parity over hour bits (29-35): DCF77 bit 35.
150	self.tmp \|= (bit << (c - 29))
151	parity = bin(self.tmp).count('1')
152	s = 'OK' if ((parity % 2) == 0) else 'INVALID!'
153	self.put(ss, es, a, [0, ['Hour parity: %s' % s]])
154	elif c in range(36, 41 + 1):
155	# Day of month (1-31): DCF77 bits 36-41 (BCD format).
156	if c == 36:
157	self.tmp = bit
158	else:
159	self.tmp \|= (bit << (c - 36))
160	if c == 41:
161	self.put(ss, es, a, [0, ['Day: %d' % bcd2int(self.tmp)]])
162	elif c in range(42, 44 + 1):
163	# Day of week (1-7): DCF77 bits 42-44 (BCD format).
164	# A value of 1 means Monday, 7 means Sunday.
165	if c == 42:
166	self.tmp = bit
167	else:
168	self.tmp \|= (bit << (c - 42))
169	if c == 44:
170	d = bcd2int(self.tmp)
171	dn = calendar.day_name[d - 1] # day_name[0] == Monday
172	self.put(ss, es, a, [0, ['Day of week: %d (%s)' % (d, dn)]])
173	elif c in range(45, 49 + 1):
174	# Month (1-12): DCF77 bits 45-49 (BCD format).
175	if c == 45:
176	self.tmp = bit
177	else:
178	self.tmp \|= (bit << (c - 45))
179	if c == 49:
180	m = bcd2int(self.tmp)
181	mn = calendar.month_name[m] # month_name[1] == January
182	self.put(ss, es, a, [0, ['Month: %d (%s)' % (m, mn)]])
183	elif c in range(50, 57 + 1):
184	# Year (0-99): DCF77 bits 50-57 (BCD format).
185	if c == 50:
186	self.tmp = bit
187	else:
188	self.tmp \|= (bit << (c - 50))
189	if c == 57:
190	self.put(ss, es, a, [0, ['Year: %d' % bcd2int(self.tmp)]])
191	elif c == 58:
192	# Even parity over date bits (36-58): DCF77 bit 58.
193	self.tmp \|= (bit << (c - 50))
194	parity = bin(self.tmp).count('1')
195	s = 'OK' if ((parity % 2) == 0) else 'INVALID!'
196	self.put(ss, es, a, [0, ['Date parity: %s' % s]])
197	else:
198	raise Exception('Invalid DCF77 bit: %d' % c)
199
200	def decode(self, ss, es, data):
2fcd7c22 UH	201	for (self.samplenum, pins) in data:
	202
	203	# Ignore identical samples early on (for performance reasons).
	204	if self.oldpins == pins:
	205	continue
	206	self.oldpins, (val, pon) = pins, pins
fcd8c14d UH	207
	208	# Always remember the old PON state.
	209	if self.oldpon != pon:
	210	self.oldpon = pon
	211
	212	# Warn if PON goes low.
	213	if self.oldpon == 1 and pon == 0:
	214	self.pon_ss = self.samplenum
	215	self.put(self.samplenum, self.samplenum, self.out_ann,
	216	[1, ['Warning: PON goes low, DCF77 reception '
	217	'no longer possible']])
	218	elif self.oldpon == 0 and pon == 1:
	219	self.put(self.samplenum, self.samplenum, self.out_ann,
	220	[0, ['PON goes high, DCF77 reception now possible']])
	221	self.put(self.pon_ss, self.samplenum, self.out_ann,
	222	[1, ['Warning: PON low, DCF77 reception disabled']])
	223
	224	# Ignore samples where PON == 0, they can't contain DCF77 signals.
	225	if pon == 0:
	226	continue
2b0915c1	227
2b716038	228	if self.state == 'WAIT FOR RISING EDGE':
2b0915c1 UH	229	# Wait until the next rising edge occurs.
	230	if not (self.oldval == 0 and val == 1):
	231	self.oldval = val
	232	continue
	233
	234	# Save the sample number where the DCF77 bit begins.
	235	self.bit_start = self.samplenum
	236
	237	# Calculate the length (in ms) between two rising edges.
	238	len_edges = self.bit_start - self.bit_start_old
	239	len_edges_ms = int((len_edges / self.samplerate) * 1000)
	240
	241	# The time between two rising edges is usually around 1000ms.
	242	# For DCF77 bit 59, there is no rising edge at all, i.e. the
	243	# time between DCF77 bit 59 and DCF77 bit 0 (of the next
	244	# minute) is around 2000ms. Thus, if we see an edge with a
	245	# 2000ms distance to the last one, this edge marks the
	246	# beginning of a new minute (and DCF77 bit 0 of that minute).
	247	if len_edges_ms in range(1600, 2400 + 1):
	248	self.put(ss, es, self.out_ann, [0, ['New minute starts']])
	249	self.bitcount = 0
	250	self.bit_start_old = self.bit_start
	251	self.dcf77_bitnumber_is_known = 1
abbc1285	252	# Don't switch to 'GET BIT' state this time.
2b0915c1 UH	253	continue
	254
	255	self.bit_start_old = self.bit_start
abbc1285	256	self.state = 'GET BIT'
2b0915c1	257
abbc1285	258	elif self.state == 'GET BIT':
2b0915c1 UH	259	# Wait until the next falling edge occurs.
	260	if not (self.oldval == 1 and val == 0):
	261	self.oldval = val
	262	continue
	263
	264	# Calculate the length (in ms) of the current high period.
	265	len_high = self.samplenum - self.bit_start
	266	len_high_ms = int((len_high / self.samplerate) * 1000)
	267
	268	# If the high signal was 100ms long, that encodes a 0 bit.
	269	# If it was 200ms long, that encodes a 1 bit.
	270	if len_high_ms in range(40, 160 + 1):
	271	bit = 0
	272	elif len_high_ms in range(161, 260 + 1):
	273	bit = 1
	274	else:
	275	bit = -1 # TODO: Error?
	276
abbc1285	277	# There's no bit 59, make sure none is decoded.
2b0915c1 UH	278	if bit in (0, 1) and self.bitcount in range(0, 58 + 1):
	279	self.handle_dcf77_bit(bit)
	280	self.bitcount += 1
	281
2b716038	282	self.state = 'WAIT FOR RISING EDGE'
2b0915c1 UH	283
2b0915c1 UH	284	else:
decde15e	285	raise Exception('Invalid state: %d' % self.state)
2b0915c1 UH	286
	287	self.oldval = val
	288