diff options
Diffstat (limited to 'decoders')
| -rw-r--r-- | decoders/caliper/__init__.py | 36 | ||||
| -rw-r--r-- | decoders/caliper/pd.py | 153 |
2 files changed, 189 insertions, 0 deletions
diff --git a/decoders/caliper/__init__.py b/decoders/caliper/__init__.py new file mode 100644 index 0000000..3fc99fe --- /dev/null +++ b/decoders/caliper/__init__.py @@ -0,0 +1,36 @@ +## +## This file is part of the libsigrokdecode project. +## +## Copyright (C) 2020 Tomas Mudrunka <harvie@github> +## +## 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, see <http://www.gnu.org/licenses/>. +## + +''' +This decodes digital output of cheap generic calipers (usualy made in china) +Decoder will show measured value in milimeters or inches. + +Please note that these devices often communicate on low voltage level, +which might not be possible to capture with 3.3V logic analyzers. +So additional circuitry might be needed to capture the signal. + +This is NOT for calipers using Digimatic protocol (eg. Mitutoyo and similar brands) + +More info: + +http://www.shumatech.com/support/chinese_scales.htm +https://www.instructables.com/id/Reading-Digital-Callipers-with-an-Arduino-USB/ +''' + +from .pd import Decoder diff --git a/decoders/caliper/pd.py b/decoders/caliper/pd.py new file mode 100644 index 0000000..3db0473 --- /dev/null +++ b/decoders/caliper/pd.py @@ -0,0 +1,153 @@ +## +## 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() |