2020-02-22 11:12:26 +08:00

139 lines
4.7 KiB
Python
Executable File

##
## This file is part of the libsigrokdecode project.
##
## Copyright (C) 2016 Vladimir Ermakov <vooon341@gmail.com>
## Copyright (C) 2019 DreamSourceLab <support@dreamsourcelab.com>
##
## 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 3 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, see <http://www.gnu.org/licenses/>.
##
import sigrokdecode as srd
from functools import reduce
class SamplerateError(Exception):
pass
class Decoder(srd.Decoder):
api_version = 3
id = 'rgb_led_ws281x'
name = 'RGB LED (WS281x)'
longname = 'RGB LED string decoder (WS281x)'
desc = 'RGB LED string protocol (WS281x).'
license = 'gplv3+'
inputs = ['logic']
outputs = []
tags = ['Display', 'IC']
channels = (
{'id': 'din', 'name': 'DIN', 'desc': 'DIN data line'},
)
annotations = (
('bit', 'Bit'),
('reset', 'RESET'),
('rgb', 'RGB'),
)
annotation_rows = (
('bit', 'Bits', (0, 1)),
('rgb', 'RGB', (2,)),
)
def __init__(self):
self.reset()
def reset(self):
self.state = 'FIND RESET'
self.samplerate = None
self.ss_packet = None
self.ss = None
self.es = None
self.bits = []
self.bit_ = None
def start(self):
self.out_ann = self.register(srd.OUTPUT_ANN)
def metadata(self, key, value):
if key == srd.SRD_CONF_SAMPLERATE:
self.samplerate = value
def handle_bits(self, samplenum):
if len(self.bits) == 24:
grb = reduce(lambda a, b: (a << 1) | b, self.bits)
rgb = (grb & 0xff0000) >> 8 | (grb & 0x00ff00) << 8 | (grb & 0x0000ff)
self.put(self.ss_packet, samplenum, self.out_ann,
[2, ['#%06x' % rgb]])
self.bits = []
self.ss_packet = samplenum
def check_bit_(self, samplenum):
period = samplenum - self.ss
tH_samples = self.es - self.ss
tH = tH_samples / self.samplerate
if tH >= 625e-9:
self.bit_ = True
else:
# Ideal duty for T0H: 33%, T1H: 66%.
self.bit_ = (tH_samples / period) > 0.5
def decode(self):
if not self.samplerate:
raise SamplerateError('Cannot decode without samplerate.')
while True:
if self.state == 'FIND RESET':
self.wait({0: 'l'})
self.ss = self.samplenum
self.wait({0: 'r'})
self.es = self.samplenum
if ((self.es - self.ss) / self.samplerate > 50e-6):
self.state = 'RESET'
elif ((self.es - self.ss) / self.samplerate > 3e-6):
self.bits = []
self.ss = self.samplenum
self.ss_packet = self.samplenum
self.wait({0: 'f'})
self.state = 'BIT FALLING'
elif self.state == 'RESET':
self.put(self.ss, self.es, self.out_ann, [1, ['RESET', 'RST', 'R']])
self.bits = []
self.ss = self.samplenum
self.ss_packet = self.samplenum
self.wait({0: 'f'})
self.state = 'BIT FALLING'
elif self.state == 'BIT FALLING':
self.es = self.samplenum
self.wait({0: 'r'})
if ((self.samplenum - self.es) / self.samplerate > 50e-6):
self.check_bit_(self.samplenum)
self.put(self.ss, self.es, self.out_ann,
[0, ['%d' % self.bit_]])
self.bits.append(self.bit_)
self.handle_bits(self.es)
self.ss = self.es
self.es = self.samplenum
self.state = 'RESET'
else:
self.state = 'BIT RISING'
elif self.state == 'BIT RISING':
self.check_bit_(self.samplenum)
self.put(self.ss, self.samplenum, self.out_ann,
[0, ['%d' % self.bit_]])
self.bits.append(self.bit_)
self.handle_bits(self.samplenum)
self.ss = self.samplenum
self.wait({0: 'f'})
self.state = 'BIT FALLING'