plugins/sigrok-decoders/caliper/pd.py

   1 ##
   2 ## This file is part of the libsigrokdecode project.
   3 ##
   4 ## Copyright (C) 2020 Tomas Mudrunka <harvie@github>
   5 ##
   6 ## Permission is hereby granted, free of charge, to any person obtaining a copy
   7 ## of this software and associated documentation files (the "Software"), to deal
   8 ## in the Software without restriction, including without limitation the rights
   9 ## to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10 ## copies of the Software, and to permit persons to whom the Software is
  11 ## furnished to do so, subject to the following conditions:
  12 ##
  13 ## The above copyright notice and this permission notice shall be included in all
  14 ## copies or substantial portions of the Software.
  15 ##
  16 ## THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17 ## IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18 ## FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  19 ## AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20 ## LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21 ## OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  22 ## SOFTWARE.
  23
  24 import sigrokdecode as srd
  25
  26 class Decoder(srd.Decoder):
  27     api_version = 3
  28     id = 'caliper'
  29     name = 'Caliper'
  30     longname = 'Digital calipers'
  31     desc = 'Protocol of cheap generic digital calipers'
  32     license = 'mit'
  33     inputs = ['logic']
  34     outputs = []
  35     channels = (
  36          {'id': 'clk', 'name': 'CLK', 'desc': 'Serial clock line'},
  37          {'id': 'data', 'name': 'DATA', 'desc': 'Serial data line'},
  38     )
  39     options = (
  40          {'id': 'timeout_ms', 'desc': 'Timeout packet after X ms, 0 to disable', 'default': 10},
  41          {'id': 'unit', 'desc': 'Convert units', 'default': 'keep', 'values': ('keep', 'mm', 'inch')},
  42     )
  43     tags = ['Analog/digital', 'IC', 'Sensor']
  44     annotations = (
  45         ('measurements', 'Measurements'),
  46         ('warning', 'Warnings'),
  47     )
  48     annotation_rows = (
  49         ('measurements', 'Measurements', (0,)),
  50         ('warnings', 'Warnings', (1,)),
  51     )
  52
  53     def reset_data(self):
  54         self.bits = 0
  55         self.number = 0
  56         self.flags = 0
  57
  58     def metadata(self, key, value):
  59        if key == srd.SRD_CONF_SAMPLERATE:
  60             self.samplerate = value
  61
  62     def __init__(self):
  63         self.reset()
  64
  65     def reset(self):
  66         self.ss_cmd, self.es_cmd = 0, 0
  67         self.reset_data()
  68
  69     def start(self):
  70         self.out_ann = self.register(srd.OUTPUT_ANN)
  71
  72     #Switch bit order of variable x, which is l bit long
  73     def bitr(self,x,l):
  74         return int(bin(x)[2:].zfill(l)[::-1], 2)
  75
  76     def decode(self):
  77         while True:
  78             clk, data = self.wait([{0: 'r'},{'skip': round(self.samplerate/1000)}])
  79             #print([clk,data])
  80
  81             #Timeout after inactivity
  82             if(self.options['timeout_ms'] > 0):
  83                 if self.samplenum > self.es_cmd + (self.samplerate/(1000/self.options['timeout_ms'])):
  84                     if self.bits > 0:
  85                         self.put(self.ss_cmd, self.samplenum, self.out_ann, [1, ['timeout with %s bits in buffer'%(self.bits),'timeout']])
  86                     self.reset()
  87
  88             #Do nothing if there was timeout without rising clock edge
  89             if self.matched == (False, True):
  90                 continue
  91
  92             #Store position of last activity
  93             self.es_cmd = self.samplenum
  94
  95             #Store position of first bit
  96             if self.ss_cmd == 0:
  97                 self.ss_cmd = self.samplenum
  98
  99             #Shift in measured number
 100             if self.bits < 16:
 101                 self.number = (self.number << 1) | (data & 0b1)
 102                 self.bits+=1
 103                 continue
 104
 105             #Shift in flag bits
 106             if self.bits < 24:
 107                 self.flags = (self.flags << 1) | (data & 0b1)
 108                 self.bits+=1
 109                 if self.bits < 24:
 110                     continue
 111                 #Hooray! We got last bit of data
 112                 self.es_cmd = self.samplenum
 113
 114             #Do actual decoding
 115
 116             #print(format(self.flags, '08b'));
 117
 118             negative = ((self.flags & 0b00001000) >> 3)
 119             inch = (self.flags & 0b00000001)
 120
 121             number = self.bitr(self.number, 16)
 122
 123             #print(format(number, '016b'))
 124
 125             if negative > 0:
 126                 number = -number
 127
 128             inchmm = 25.4 #how many mms in inch
 129
 130             if inch:
 131                 number = number/2000
 132                 if self.options['unit'] == 'mm':
 133                     number *= inchmm
 134                     inch = 0
 135             else:
 136                 number = number/100
 137                 if self.options['unit'] == 'inch':
 138                     number = round(number/inchmm,4)
 139                     inch = 1
 140
 141             units = "in" if inch else "mm"
 142
 143             measurement = (str(number)+units)
 144             #print(measurement)
 145
 146             self.put(self.ss_cmd, self.es_cmd, self.out_ann, [0, [measurement, str(number)]])
 147
 148             #Prepare for next packet
 149             self.reset()