From 69ada057e0a8ed086d89d976b1c78e22bea26a77 Mon Sep 17 00:00:00 2001 From: Uwe Hermann Date: Sun, 15 Sep 2013 20:07:03 +0200 Subject: dcf77: Fix date parity check. The parity check for certain DCF77 fields/bits was incorrect. It has to be an even parity over bits 36-58. This is fixed now. This fixes bug #157. --- decoders/dcf77/pd.py | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/decoders/dcf77/pd.py b/decoders/dcf77/pd.py index 0c53f41..a31c313 100644 --- a/decoders/dcf77/pd.py +++ b/decoders/dcf77/pd.py @@ -70,6 +70,7 @@ class Decoder(srd.Decoder): self.oldval = None self.samplenum = 0 self.ss_bit = self.ss_bit_old = self.es_bit = self.ss_block = 0 + self.datebits = [] self.bitcount = 0 # Counter for the DCF77 bits (0..58) self.dcf77_bitnumber_is_known = 0 @@ -106,6 +107,10 @@ class Decoder(srd.Decoder): if not self.dcf77_bitnumber_is_known: return + # Collect bits 36-58, we'll need them for a parity check later. + if c in range(36, 58 + 1): + self.datebits.append(bit) + # Output specific "decoded" annotations for the respective DCF77 bits. if c == 0: # Start of minute: DCF bit 0. @@ -231,10 +236,10 @@ class Decoder(srd.Decoder): self.putb([15, ['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') + parity = self.datebits.count(1) s = 'OK' if ((parity % 2) == 0) else 'INVALID!' self.putx([16, ['Date parity: %s' % s, 'DP: %s' %s]]) + self.datebits = [] else: raise Exception('Invalid DCF77 bit: %d' % c) -- cgit v1.2.3-70-g09d2