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##
## This file is part of the libsigrokdecode project.
##
## Copyright (C) 2015 Petteri Aimonen <jpa@sigrok.mail.kapsi.fi>
##
## 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/>.
##
import sigrokdecode as srd
class Decoder(srd.Decoder):
api_version = 3
id = 'stepper_motor'
name = 'Stepper motor'
longname = 'Stepper motor position / speed'
desc = 'Absolute position and movement speed from step/dir.'
license = 'gplv2+'
inputs = ['logic']
outputs = []
tags = ['Embedded/industrial']
channels = (
{'id': 'step', 'name': 'Step', 'desc': 'Step pulse'},
{'id': 'dir', 'name': 'Direction', 'desc': 'Direction select'},
)
options = (
{'id': 'unit', 'desc': 'Unit', 'default': 'steps',
'values': ('steps', 'mm')},
{'id': 'steps_per_mm', 'desc': 'Steps per mm', 'default': 100.0},
)
annotations = (
('speed', 'Speed'),
('position', 'Position')
)
annotation_rows = (
('speeds', 'Speeds', (0,)),
('positions', 'Positions', (1,)),
)
def __init__(self):
self.reset()
def reset(self):
self.samplerate = None
self.oldstep = None
self.ss_prev_step = None
self.pos = 0
self.prev_speed = None
self.prev_pos = None
def start(self):
self.out_ann = self.register(srd.OUTPUT_ANN)
if self.options['unit'] == 'steps':
self.scale = 1
self.format = '%0.0f'
self.unit = 'steps'
else:
self.scale = self.options['steps_per_mm']
self.format = '%0.2f'
self.unit = 'mm'
def step(self, ss, direction):
if self.ss_prev_step is not None:
if self.samplerate:
delta = ss - self.ss_prev_step
speed = self.samplerate / delta / self.scale
speed_txt = self.format % speed
self.put(self.ss_prev_step, ss, self.out_ann,
[0, [speed_txt + ' ' + self.unit + '/s', speed_txt]])
pos_txt = self.format % (self.pos / self.scale)
self.put(self.ss_prev_step, ss, self.out_ann,
[1, [pos_txt + ' ' + self.unit, pos_txt]])
self.pos += (1 if direction else -1)
self.ss_prev_step = ss
def metadata(self, key, value):
if key == srd.SRD_CONF_SAMPLERATE:
self.samplerate = value
def decode(self):
while True:
step, direction = self.wait({0: 'r'})
self.step(self.samplenum, direction)
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