diff options
Diffstat (limited to 'decoders/ir_nec/pd.py')
| -rw-r--r-- | decoders/ir_nec/pd.py | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/decoders/ir_nec/pd.py b/decoders/ir_nec/pd.py index 0362609..02d70a9 100644 --- a/decoders/ir_nec/pd.py +++ b/decoders/ir_nec/pd.py @@ -38,6 +38,7 @@ class Decoder(srd.Decoder): options = ( {'id': 'polarity', 'desc': 'Polarity', 'default': 'active-low', 'values': ('active-low', 'active-high')}, + {'id': 'cd_freq', 'desc': 'Carrier Frequency', 'default': 0}, ) annotations = ( ('bit', 'Bit'), @@ -158,9 +159,36 @@ class Decoder(srd.Decoder): def decode(self): if not self.samplerate: raise SamplerateError('Cannot decode without samplerate.') + + cd_count = None + if self.options['cd_freq']: + cd_count = int(self.samplerate / self.options['cd_freq']) + 1 + prev_ir = None + while True: - # Wait for any edge (rising or falling). - (self.ir,) = self.wait({0: 'e'}) + # Detect changes in the presence of an active input signal. + # The decoder can either be fed an already filtered RX signal + # or optionally can detect the presence of a carrier. Periods + # of inactivity (signal changes slower than the carrier freq, + # if specified) pass on the most recently sampled level. This + # approach works for filtered and unfiltered input alike, and + # only slightly extends the active phase of input signals with + # carriers included by one period of the carrier frequency. + # IR based communication protocols can cope with this slight + # inaccuracy just fine by design. Enabling carrier detection + # on already filtered signals will keep the length of their + # active period, but will shift their signal changes by one + # carrier period before they get passed to decoding logic. + if cd_count: + (cur_ir,) = self.wait([{0: 'e'}, {'skip': cd_count}]) + if self.matched[0]: + cur_ir = self.active + if cur_ir == prev_ir: + continue + prev_ir = cur_ir + self.ir = cur_ir + else: + (self.ir,) = self.wait({0: 'e'}) if self.ir != self.active: # Save the non-active edge, then wait for the next edge. |