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##
## This file is part of the libsigrokdecode project.
##
## Copyright (C) 2020 Tomas Mudrunka <harvie@github>
##
## Permission is hereby granted, free of charge, to any person obtaining a copy
## of this software and associated documentation files (the "Software"), to deal
## in the Software without restriction, including without limitation the rights
## to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
## copies of the Software, and to permit persons to whom the Software is
## furnished to do so, subject to the following conditions:
##
## The above copyright notice and this permission notice shall be included in all
## copies or substantial portions of the Software.
##
## THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
## IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
## FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
## AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
## LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
## OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
## SOFTWARE.
import sigrokdecode as srd
from common.srdhelper import bitpack
# Millimeters per inch.
mm_per_inch = 25.4
class Decoder(srd.Decoder):
api_version = 3
id = 'caliper'
name = 'Caliper'
longname = 'Digital calipers'
desc = 'Protocol of cheap generic digital calipers.'
license = 'mit'
inputs = ['logic']
outputs = []
channels = (
{'id': 'clk', 'name': 'CLK', 'desc': 'Serial clock line'},
{'id': 'data', 'name': 'DATA', 'desc': 'Serial data line'},
)
options = (
{'id': 'timeout_ms', 'desc': 'Packet timeout in ms, 0 to disable',
'default': 10},
{'id': 'unit', 'desc': 'Convert units', 'default': 'keep',
'values': ('keep', 'mm', 'inch')},
{'id': 'changes', 'desc': 'Changes only', 'default': 'no',
'values': ('no', 'yes')},
)
tags = ['Analog/digital', 'Sensor']
annotations = (
('measurement', 'Measurement'),
('warning', 'Warning'),
)
annotation_rows = (
('measurements', 'Measurements', (0,)),
('warnings', 'Warnings', (1,)),
)
def metadata(self, key, value):
if key == srd.SRD_CONF_SAMPLERATE:
self.samplerate = value
def __init__(self):
self.reset()
def reset(self):
self.ss, self.es = 0, 0
self.number_bits = []
self.flags_bits = []
def start(self):
self.out_ann = self.register(srd.OUTPUT_ANN)
def putg(self, ss, es, cls, data):
self.put(ss, es, self.out_ann, [cls, data])
def decode(self):
last_measurement = None
timeout_ms = self.options['timeout_ms']
want_unit = self.options['unit']
show_all = self.options['changes'] == 'no'
wait_cond = [{0: 'r'}]
if timeout_ms:
snum_per_ms = self.samplerate / 1000
timeout_snum = timeout_ms * snum_per_ms
wait_cond.append({'skip': round(timeout_snum)})
while True:
# Sample data at the rising clock edge. Optionally timeout
# after inactivity for a user specified period. Present the
# number of unprocessed bits to the user for diagnostics.
clk, data = self.wait(wait_cond)
if timeout_ms and not self.matched[0]:
if self.number_bits or self.flags_bits:
count = len(self.number_bits) + len(self.flags_bits)
self.putg(self.ss, self.samplenum, 1, [
'timeout with {} bits in buffer'.format(count),
'timeout ({} bits)'.format(count),
'timeout',
])
self.reset()
continue
# Store position of first bit and last activity.
# Shift in measured number and flag bits.
if not self.ss:
self.ss = self.samplenum
self.es = self.samplenum
if len(self.number_bits) < 16:
self.number_bits.append(data)
continue
if len(self.flags_bits) < 8:
self.flags_bits.append(data)
if len(self.flags_bits) < 8:
continue
# Get raw values from received data bits. Run the number
# conversion, controlled by flags and/or user specs.
negative = bool(self.flags_bits[4])
is_inch = bool(self.flags_bits[7])
number = bitpack(self.number_bits)
if negative:
number = -number
if is_inch:
number = number / 2000
if want_unit == 'mm':
number *= mm_per_inch
is_inch = False
else:
number = number / 100
if want_unit == 'inch':
number = round(number / mm_per_inch, 4)
is_inch = True
units = "in" if is_inch else "mm"
measurement = (str(number) + units)
if show_all or measurement != last_measurement:
self.putg(self.ss, self.es, 0, [
measurement,
str(number),
])
last_measurement = measurement
# Prepare for next packet.
self.reset()
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