1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
|
#!/usr/bin/python3
# CodeQ: an online programming tutor.
# Copyright (C) 2015 UL FRI
#
# This program is free software: you can redistribute it and/or modify it under
# the terms of the GNU Affero General Public License as published by the Free
# Software Foundation, either version 3 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 Affero General Public License for more
# details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
# This file must be run on the EV3 brick. It serves websocket connections,
# sending sensor updates and running user programs.
PORT = 8000
import json
import multiprocessing
import os
import os.path
import signal
import engineio
import eventlet
import ev3dev
ev3_names = {
'lego-ev3-color': 'Color',
'lego-ev3-gyro': 'Gyroscope',
'lego-ev3-touch': 'Touch',
'lego-ev3-us': 'Ultrasonic'
}
ev3_motors = [
ev3dev.motor(ev3dev.OUTPUT_A),
ev3dev.motor(ev3dev.OUTPUT_B),
ev3dev.motor(ev3dev.OUTPUT_C),
ev3dev.motor(ev3dev.OUTPUT_D)
]
connections = set()
process = None
def _run_exec(program):
import ev3dev
from mindstorms_widgets import mindstorms_widgets
exec(program)
def run(program):
global process
stop()
process = multiprocessing.Process(target=_run_exec, args=[program])
process.start()
def stop():
global process
if process is not None:
try:
os.kill(process.pid, signal.SIGKILL)
except:
pass
process = None
for motor in ev3_motors:
if motor.connected:
motor.stop(stop_command='brake')
def notifier():
sensors_path = '/sys/class/lego-sensor'
sensors = {}
for sensor in os.listdir(sensors_path):
path = os.path.join(sensors_path, sensor)
with open(os.path.join(path, 'driver_name'), 'r') as f:
name = f.read().strip()
with open(os.path.join(path, 'decimals'), 'r') as f:
decimals = int(f.read().strip())
multiplier = 10**(-decimals)
with open(os.path.join(path, 'units'), 'r') as f:
unit = f.read().strip()
friendly_name = ev3_names.get(name, name)
sensors[path] = (friendly_name, multiplier, unit)
while True:
eventlet.sleep(0.2)
try:
message = {'event': 'update', 'sensors': {}}
for path, (name, multiplier, unit) in sorted(sensors.items()):
with open(os.path.join(path, 'value0'), 'rb') as f:
value = round(int(f.read().strip()) * multiplier, 1)
if unit:
value = '{} {}'.format(value, unit)
message['sensors'][name] = value
text = json.dumps(message)
for sid in connections:
eio.send(sid, text)
except:
pass
eio = engineio.Server(async_mode='eventlet', cookie=None)
app = engineio.Middleware(eio)
@eio.on('connect')
def connect(sid, environ):
print('New connection: {}'.format(sid))
connections.add(sid)
@eio.on('disconnect')
def disconnect(sid):
print('Dropped connection: {}'.format(sid))
try:
connections.remove(sid)
except:
pass
@eio.on('message')
def message(sid, msg):
reply = None
action = msg.get('action')
if action is None:
reply = {'code': 1, 'message': 'Request does not contain an action'}
elif action == 'run':
program = msg.get('program')
if program is None:
reply = {'code': 2, 'message': 'Program not specified'}
else:
run(program)
reply = {'code': 0}
elif action == 'stop':
stop()
reply = {'code': 0}
eio.send(sid, reply)
eventlet.spawn_n(notifier)
eventlet.wsgi.server(eventlet.listen(('', PORT)), app)
|
