pump-server

#!/usr/bin/python

# Copyright 2013 Michigan Technological University
# Author: Bas Wijnen <bwijnen@mtu.edu>
# This design was developed as part of a project with
# the Michigan Tech Open Sustainability Technology Research Group
# http://www.appropedia.org/Category:MOST
#
# 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/>.

import websockets
import sys
import argparse
import time
try:
	import RPi.GPIO as gpio
	gpio.setwarnings(False)
	gpio.setmode(gpio.BOARD)
except:
	sys.stderr.write('Warning: using emulation because RPi.GPIO could not be used\n')
	class gpio:
		LOW = 0
		HIGH = 1
		IN = 0
		OUT = 1
		@classmethod
		def output(cls, pin, state):
			pass
		@classmethod
		def setup(cls, pin, type, initial):
			pass
DIR = 11
STEP = 13
SLEEP = 15
MS3 = 19
MS2 = 21
MS1 = 23
gpio.setup(SLEEP, gpio.OUT, initial = gpio.HIGH)
gpio.setup(STEP, gpio.OUT, initial = gpio.HIGH)
gpio.setup(DIR, gpio.OUT, initial = gpio.HIGH)
gpio.setup(MS1, gpio.OUT, initial = gpio.HIGH)
gpio.setup(MS2, gpio.OUT, initial = gpio.HIGH)
gpio.setup(MS3, gpio.OUT, initial = gpio.HIGH)

a = argparse.ArgumentParser()
a.add_argument('--port', help = 'port to listen on(8000)', default = '8000')
a.add_argument('--pitch', help = 'lead screw pitch(.8 mm; M5)', default = .8, type = float)
a.add_argument('--steps', help = 'motor steps per revolution(3200)', default = 3200, type = float)
a.add_argument('--html', help = 'path to html files', default = 'html')
args = a.parse_args()

class Pump:
	def __init__(self, pitch, steps):
		self.position = 0.
		self.steps_per_mm = steps / pitch
		self.ml_per_s = .7
		self.ml_per_mm = 0.16355310023987787
	def calibrate(self, ml_per_mm):
		self.ml_per_mm = ml_per_mm * 1.
		notify('calibration', self.ml_per_mm)
	def setposition(self, position):
		self.position = position
		notify('position', self.position)
	def goto(self, ml):
		self.move(ml - self.position)
	def move(self, ml):
		gpio.output(SLEEP, gpio.HIGH)
		gpio.output(DIR, gpio.HIGH if ml < 0 else gpio.LOW)
		notify('move', self.position, ml)
		# ml/mm
		# ml/s
		# step/mm
		# ml
		# s/step ?
		s_per_half_step = self.ml_per_mm / self.steps_per_mm / self.ml_per_s / 2
		steps = int(ml / self.ml_per_mm * self.steps_per_mm + .5)
		target = time.time()
		for t in range(abs(steps)):
			gpio.output(STEP, gpio.HIGH)
			target += s_per_half_step
			while time.time() < target:
				# Yes, this is a busy wait.
				pass
			gpio.output(STEP, gpio.LOW)
			target += s_per_half_step
			while time.time() < target:
				# Yes, this is a busy wait.
				pass
		self.position += ml
		notify('position', self.position)
	def speed(self, ml_per_s):
		self.ml_per_s = ml_per_s
		notify('speed', ml_per_s)
	def sleep(self):
		gpio.output(SLEEP, gpio.LOW)

users = set()

def send(socket, arg):
	getattr(socket, 'notify') (*arg)
def notify(*arg):
	for u in users:
		send(u, arg)

p = Pump(args.pitch, args.steps)

class Connection:
	def __init__(self, socket):
		self.socket = socket
	def monitor(self):
		users.add(self.socket)
		return(('calibration', p.ml_per_mm), ('position', p.position), ('speed', p.ml_per_s))
	def __getattr__(self, attr):
		return getattr(p, attr)

def disconnect(socket):
	if socket in users:
		users.remove(socket)

s = websockets.RPChttpd(args.port, httpdirs = args.html.split(), target = Connection, disconnect_cb = disconnect)
websockets.fgloop()