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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
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': 'Timeout packet after X 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', 'IC', 'Sensor']
annotations = (
('measurements', 'Measurements'),
('warning', 'Warnings'),
)
annotation_rows = (
('measurements', 'Measurements', (0,)),
('warnings', 'Warnings', (1,)),
)
def reset_data(self):
self.bits = 0
self.number = 0
self.flags = 0
def metadata(self, key, value):
if key == srd.SRD_CONF_SAMPLERATE:
self.samplerate = value
def __init__(self):
self.reset()
def reset(self):
self.ss_cmd, self.es_cmd = 0, 0
self.reset_data()
def start(self):
self.out_ann = self.register(srd.OUTPUT_ANN)
#Switch bit order of variable x, which is l bit long
def bitr(self,x,l):
return int(bin(x)[2:].zfill(l)[::-1], 2)
def decode(self):
self.last_measurement = None
while True:
clk, data = self.wait([{0: 'r'},{'skip': round(self.samplerate/1000)}])
#print([clk,data])
#Timeout after inactivity
if(self.options['timeout_ms'] > 0):
if self.samplenum > self.es_cmd + (self.samplerate/(1000/self.options['timeout_ms'])):
if self.bits > 0:
self.put(self.ss_cmd, self.samplenum, self.out_ann, [1, ['timeout with %s bits in buffer'%(self.bits),'timeout']])
self.reset()
#Do nothing if there was timeout without rising clock edge
if self.matched == (False, True):
continue
#Store position of last activity
self.es_cmd = self.samplenum
#Store position of first bit
if self.ss_cmd == 0:
self.ss_cmd = self.samplenum
#Shift in measured number
if self.bits < 16:
self.number = (self.number << 1) | (data & 0b1)
self.bits+=1
continue
#Shift in flag bits
if self.bits < 24:
self.flags = (self.flags << 1) | (data & 0b1)
self.bits+=1
if self.bits < 24:
continue
#Hooray! We got last bit of data
self.es_cmd = self.samplenum
#Do actual decoding
#print(format(self.flags, '08b'));
negative = ((self.flags & 0b00001000) >> 3)
inch = (self.flags & 0b00000001)
number = self.bitr(self.number, 16)
#print(format(number, '016b'))
if negative > 0:
number = -number
inchmm = 25.4 #how many mms in inch
if inch:
number = number/2000
if self.options['unit'] == 'mm':
number *= inchmm
inch = 0
else:
number = number/100
if self.options['unit'] == 'inch':
number = round(number/inchmm,4)
inch = 1
units = "in" if inch else "mm"
measurement = (str(number)+units)
#print(measurement)
if ((self.options['changes'] == 'no') or (self.last_measurement != measurement)):
self.put(self.ss_cmd, self.es_cmd, self.out_ann, [0, [measurement, str(number)]])
self.last_measurement = measurement
#Prepare for next packet
self.reset()
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