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-rw-r--r--decoders/ir_nec/pd.py27
1 files changed, 19 insertions, 8 deletions
diff --git a/decoders/ir_nec/pd.py b/decoders/ir_nec/pd.py
index 3c272db..ecd2b7a 100644
--- a/decoders/ir_nec/pd.py
+++ b/decoders/ir_nec/pd.py
@@ -21,6 +21,17 @@ from common.srdhelper import bitpack
from .lists import *
import sigrokdecode as srd
+# Concentrate all timing constraints of the IR protocol here in a single
+# location at the top of the source, to raise awareness and to simplify
+# review and adjustment.
+_TIME_TOL = 5 # tolerance, in percent
+_TIME_LC = 13.5 # leader code, in ms
+_TIME_RC = 11.25 # repeat code, in ms
+_TIME_ZERO = 1.125 # zero data bit, in ms
+_TIME_ONE = 2.25 # one data bit, in ms
+_TIME_STOP = 0.652 # stop bit, in ms
+_TIME_IDLE = 20.0 # inter frame timeout, in ms, arbitrary choice
+
class SamplerateError(Exception):
pass
@@ -48,7 +59,7 @@ class Decoder(srd.Decoder):
options = (
{'id': 'polarity', 'desc': 'Polarity', 'default': 'active-low',
'values': ('auto', 'active-low', 'active-high')},
- {'id': 'tolerance', 'desc': 'Timing tolerance (%)', 'default': 5},
+ {'id': 'tolerance', 'desc': 'Timing tolerance (%)', 'default': _TIME_TOL},
{'id': 'cd_freq', 'desc': 'Carrier Frequency', 'default': 0},
{'id': 'extended', 'desc': 'Extended NEC Protocol',
'default': 'no', 'values': ('yes', 'no')},
@@ -137,13 +148,13 @@ class Decoder(srd.Decoder):
self.samplerate = value
def calc_rate(self):
- self.tolerance = self.options['tolerance'] / 100 # 5% by default
- self.lc = int(self.samplerate * 0.0135) - 1 # 13.5ms
- self.rc = int(self.samplerate * 0.01125) - 1 # 11.25ms
- self.dazero = int(self.samplerate * 0.001125) - 1 # 1.125ms
- self.daone = int(self.samplerate * 0.00225) - 1 # 2.25ms
- self.stop = int(self.samplerate * 0.000652) - 1 # 0.652ms
- self.idle_to = int(self.samplerate * 0.020) - 1 # 20ms, arbitrary choice
+ self.tolerance = self.options['tolerance'] / 100
+ self.lc = int(self.samplerate * _TIME_LC / 1000) - 1
+ self.rc = int(self.samplerate * _TIME_RC / 1000) - 1
+ self.dazero = int(self.samplerate * _TIME_ZERO / 1000) - 1
+ self.daone = int(self.samplerate * _TIME_ONE / 1000) - 1
+ self.stop = int(self.samplerate * _TIME_STOP / 1000) - 1
+ self.idle_to = int(self.samplerate * _TIME_IDLE / 1000) - 1
def compare_with_tolerance(self, measured, base):
return (measured >= base * (1 - self.tolerance)