2 ## This file is part of the libsigrokdecode project.
4 ## Copyright (C) 2015 Petteri Aimonen <jpa@sigrok.mail.kapsi.fi>
6 ## This program is free software; you can redistribute it and/or modify
7 ## it under the terms of the GNU General Public License as published by
8 ## the Free Software Foundation; either version 2 of the License, or
9 ## (at your option) any later version.
11 ## This program is distributed in the hope that it will be useful,
12 ## but WITHOUT ANY WARRANTY; without even the implied warranty of
13 ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 ## GNU General Public License for more details.
16 ## You should have received a copy of the GNU General Public License
17 ## along with this program; if not, see <http://www.gnu.org/licenses/>.
20 import sigrokdecode as srd
22 class SamplerateError(Exception):
25 class Decoder(srd.Decoder):
28 name = 'Stepper motor'
29 longname = 'Stepper motor position / speed'
30 desc = 'Absolute position and movement speed from step/dir.'
33 outputs = ['stepper_motor']
35 {'id': 'step', 'name': 'Step', 'desc': 'Step pulse'},
36 {'id': 'dir', 'name': 'Direction', 'desc': 'Direction select'},
39 {'id': 'unit', 'desc': 'Unit', 'default': 'steps',
40 'values': ('steps', 'mm')},
41 {'id': 'steps_per_mm', 'desc': 'Steps per mm', 'default': 100.0},
45 ('position', 'Position')
48 ('speed', 'Speed', (0,)),
49 ('position', 'Position', (1,)),
54 self.ss_prev_step = None
56 self.prev_speed = None
60 self.out_ann = self.register(srd.OUTPUT_ANN)
62 if self.options['unit'] == 'steps':
67 self.scale = self.options['steps_per_mm']
71 def step(self, ss, direction):
72 if self.ss_prev_step is not None:
73 delta = ss - self.ss_prev_step
74 speed = self.samplerate / delta / self.scale
75 speed_txt = self.format % speed
76 pos_txt = self.format % (self.pos / self.scale)
77 self.put(self.ss_prev_step, ss, self.out_ann,
78 [0, [speed_txt + ' ' + self.unit + '/s', speed_txt]])
79 self.put(self.ss_prev_step, ss, self.out_ann,
80 [1, [pos_txt + ' ' + self.unit, pos_txt]])
82 self.pos += (1 if direction else -1)
83 self.ss_prev_step = ss
85 def metadata(self, key, value):
86 if key == srd.SRD_CONF_SAMPLERATE:
87 self.samplerate = value
90 if not self.samplerate:
91 raise SamplerateError('Cannot decode without samplerate.')
93 step, direction = self.wait({0: 'r'})
94 self.step(self.samplenum, direction)