Pass multiple samples to the protocol decoder and adapt transitioncounter.py to work...

[libsigrokdecode.git] / decoders / transitioncounter.py

##
## This file is part of the sigrok project.
##
## Copyright (C) 2010 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
##
import sigrok

lastsample = None
oldbit = None
transitions = None
rising = None
falling = None


def decode(sampledata):
	"""Counts the low->high and high->low transitions in the specified
	   channel(s) of the signal."""
	global lastsample
	global oldbit, transitions, rising, falling

	# TODO: Don't hardcode the number of channels.
	channels = 8	

	# FIXME: Get the data in the correct format in the first place.
	inbuf = [ord(x) for x in sampledata['data']]

	if lastsample == None:
		oldbit = [0] * channels
		transitions = [0] * channels
		rising = [0] * channels
		falling = [0] * channels

		# Initial values.
		lastsample = inbuf[0]
		for i in range(channels):
			oldbit[i] = (lastsample & (1 << i)) >> i
		
	# TODO: Handle LAs with more/less than 8 channels.
	for s in inbuf:
		# Optimization: Skip identical bytes (no transitions).
		if lastsample != s:
			for i in range(channels):
				curbit = (s & (1 << i)) >> i
				# Optimization: Skip identical bits (no transitions).
				if oldbit[i] == curbit:
					continue
				elif (oldbit[i] == 0 and curbit == 1):
					rising[i] += 1
				elif (oldbit[i] == 1 and curbit == 0):
					falling[i] += 1
				oldbit[i] = curbit

			# Total number of transitions is the sum of rising and falling edges.
			for i in range(channels):
				transitions[i] = rising[i] + falling[i]
		
			lastsample = s
			print(transitions)

	sigrok.put(sampledata)

register = {
	'id': 'transitioncounter',
	'name': 'Transition counter',
	'longname': '...',
	'desc': 'Counts rising/falling edges in the signal.',
	'longdesc': '...',
	'author': 'Uwe Hermann',
	'email': 'uwe@hermann-uwe.de',
	'license': 'gplv2+',
	'in': ['logic'],
	'out': ['transitioncounts'],
	'probes': [
		# All probes.
	],
	'options': {
		# No options so far.
	},
	# 'start': start,
	# 'report': report,
}

# Use psyco (if available) as it results in huge performance improvements.
try:
	import psyco
	psyco.bind(decode)
except ImportError:
	pass