From 2cd9b19718ec7a21186d15634062b2409e4e5813 Mon Sep 17 00:00:00 2001 From: Uwe Hermann Date: Tue, 28 Jun 2016 22:23:09 +0200 Subject: timing: Add frequency and averaging support. This patch was contributed by James Sleeman , thanks! --- decoders/timing/pd.py | 53 +++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 41 insertions(+), 12 deletions(-) (limited to 'decoders') diff --git a/decoders/timing/pd.py b/decoders/timing/pd.py index e0795f3..98677b9 100644 --- a/decoders/timing/pd.py +++ b/decoders/timing/pd.py @@ -20,19 +20,29 @@ ## import sigrokdecode as srd +from collections import deque class SamplerateError(Exception): pass def normalize_time(t): if t >= 1.0: - return '%.3f s' % t + return '%.3f s (%.3f Hz)' % (t, (1/t)) elif t >= 0.001: - return '%.3f ms' % (t * 1000.0) + if 1/t/1000 < 1: + return '%.3f ms (%.3f Hz)' % (t * 1000.0, (1/t)) + else: + return '%.3f ms (%.3f kHz)' % (t * 1000.0, (1/t)/1000) elif t >= 0.000001: - return '%.3f μs' % (t * 1000.0 * 1000.0) + if 1/t/1000/1000 < 1: + return '%.3f μs (%.3f kHz)' % (t * 1000.0 * 1000.0, (1/t)/1000) + else: + return '%.3f μs (%.3f MHz)' % (t * 1000.0 * 1000.0, (1/t)/1000/1000) elif t >= 0.000000001: - return '%.3f ns' % (t * 1000.0 * 1000.0 * 1000.0) + if 1/t/1000/1000/1000: + return '%.3f ns (%.3f MHz)' % (t * 1000.0 * 1000.0 * 1000.0, (1/t)/1000/1000) + else: + return '%.3f ns (%.3f GHz)' % (t * 1000.0 * 1000.0 * 1000.0, (1/t)/1000/1000/1000) else: return '%f' % t @@ -40,7 +50,7 @@ class Decoder(srd.Decoder): api_version = 2 id = 'timing' name = 'Timing' - longname = 'Timing calculation' + longname = 'Timing calculation with frequency and averaging' desc = 'Calculate time between edges.' license = 'gplv2+' inputs = ['logic'] @@ -50,15 +60,22 @@ class Decoder(srd.Decoder): ) annotations = ( ('time', 'Time'), + ('average', 'Average'), ) annotation_rows = ( ('time', 'Time', (0,)), + ('average', 'Average', (1,)), + ) + options = ( + { 'id': 'avg_period', 'desc': 'Averaging period', 'default': 100 }, ) def __init__(self): self.samplerate = None self.oldpin = None self.last_samplenum = None + self.last_n = deque() + self.chunks = 0 def metadata(self, key, value): if key == srd.SRD_CONF_SAMPLERATE: @@ -72,10 +89,6 @@ class Decoder(srd.Decoder): raise SamplerateError('Cannot decode without samplerate.') for (self.samplenum, (pin,)) in data: - # Ignore identical samples early on (for performance reasons). - if self.oldpin == pin: - continue - if self.oldpin is None: self.oldpin = pin self.last_samplenum = self.samplenum @@ -84,10 +97,26 @@ class Decoder(srd.Decoder): if self.oldpin != pin: samples = self.samplenum - self.last_samplenum t = samples / self.samplerate + self.chunks += 1 + + # Don't insert the first chunk into the averaging as it is + # not complete probably. + if self.last_samplenum is None or self.chunks < 2: + # Report the timing normalized. + self.put(self.last_samplenum, self.samplenum, self.out_ann, + [0, [normalize_time(t)]]) + else: + if t > 0: + self.last_n.append(t) + + if len(self.last_n) > self.options['avg_period']: + self.last_n.popleft() - # Report the timing normalized. - self.put(self.last_samplenum, self.samplenum, self.out_ann, - [0, [normalize_time(t)]]) + # Report the timing normalized. + self.put(self.last_samplenum, self.samplenum, self.out_ann, + [0, [normalize_time(t)]]) + self.put(self.last_samplenum, self.samplenum, self.out_ann, + [1, [normalize_time(sum(self.last_n) / len(self.last_n))]]) # Store data for next round. self.last_samplenum = self.samplenum -- cgit v1.2.3-70-g09d2