calibrateextruder.py

#!/usr/bin/python
#Interactive RepRap e axis calibration program
#(C) Nathan Zadoks 2011
#Licensed under CC-BY-SA or GPLv2 and higher - Pick your poison.
s=300			#Extrusion speed (mm/min)
n=100			#Default length to extrude
m=  0			#User-entered measured extrusion length
k=300			#Default amount of steps per mm
port='/dev/ttyUSB0'	#Default serial port to connect to printer
temp=210		#Default extrusion temperature

tempmax=250		#Maximum extrusion temperature

t=int(n*60)/s #Time to wait for extrusion

try:
	from printdummy import printcore
except ImportError:
	from printcore import printcore
import time,getopt,sys,os

def float_input(prompt=''):
	import sys
	f=None
	while f==None:
		s=raw_input(prompt)
		try:
			f=float(s)
		except ValueError:
			sys.stderr.write("Not a valid floating-point number.\n")
			sys.stderr.flush()
	return f
def wait(t,m=''):
	import time,sys
	sys.stdout.write(m+'['+(' '*t)+']\r'+m+'[')
	sys.stdout.flush()
	for i in range(t):
		for s in ['|\b','/\b','-\b','\\\b','|']:
			sys.stdout.write(s)
			sys.stdout.flush()
			time.sleep(1.0/5)
	print
def w(s):
	sys.stdout.write(s)
	sys.stdout.flush()


def heatup(p,temp,s=0):
	curtemp=gettemp(p)
	p.send_now('M109 S%03d'%temp)
	p.temp=0
	if not s: w("Heating extruder up..")
	f=False
	while curtemp<=(temp-1):
		p.send_now('M105')
		time.sleep(0.5)
		if not f:
			time.sleep(1.5)
			f=True
		curtemp=gettemp(p)
		if curtemp: w(u"\rHeating extruder up.. %3d \xb0C"%curtemp)
	if s: print
	else: print "\nReady."

def gettemp(p):
	try: p.logl
	except: setattr(p,'logl',0)
	try: p.temp
	except: setattr(p,'temp',0)
	for n in range(p.logl,len(p.log)):
		line=p.log[n]
		if 'T:' in line:
			try:
				setattr(p,'temp',int(line.split('T:')[1].split()[0]))
			except: print line
	p.logl=len(p.log)
	return p.temp
if not os.path.exists(port):
	port=0

#Parse options
help=u"""
%s [ -l DISTANCE ] [ -s STEPS ] [ -t TEMP ] [ -p PORT ]
	-l	--length	Length of filament to extrude for each calibration step (default: %d mm)
	-s	--steps		Initial amount of steps to use (default: %d steps)
	-t	--temp		Extrusion temperature in degrees Celsius (default: %d \xb0C, max %d \xb0C)
	-p	--port		Serial port the printer is connected to (default: %s)
	-h	--help		This cruft.
"""[1:-1].encode('utf-8')%(sys.argv[0],n,k,temp,tempmax,port if port else 'auto')
try:
	opts,args=getopt.getopt(sys.argv[1:],"hl:s:t:p:",["help","length=","steps=","temp=","port="])
except getopt.GetoptError,err:
	print str(err)
	print help
	sys.exit(2)
for o,a in opts:
	if o in ('-h','--help'):
		print help
		sys.exit()
	elif o in ('-l','--length'):
		n=float(a)
	elif o in ('-s','--steps'):
		k=int(a)
	elif o in ('-t','--temp'):
		temp=int(a)
		if temp>=tempmax:
			print (u'%d \xb0C? Are you insane?'.encode('utf-8')%temp)+(" That's over nine thousand!" if temp>9000 else '')
			sys.exit(255)
	elif o in ('-p','--port'):
		port=a

#Show initial parameters
print "Initial parameters"
print "Steps per mm:    %3d steps"%k
print "Length extruded: %3d mm"%n
print 
print "Serial port:     %s"%(port if port else 'auto')

p=None
try:
	#Connect to printer
	w("Connecting to printer..")
	try:
		p=printcore(port,115200)
	except:
		print 'Error.'
		raise
	while not p.online:
		time.sleep(1)
		w('.')
	print " connected."
	
	heatup(p,temp)
	
	#Calibration loop
	while n!=m:
		heatup(p,temp,True)
		p.send_now("G92 E0")			#Reset e axis
		p.send_now("G1 E%d F%d"%(n,s))	#Extrude length of filament
		wait(t,'Extruding.. ')
		m=float_input("How many millimeters of filament were extruded? ")
		if m==0: continue
		if n!=m:
			k=(n/m)*k
			p.send_now("M92 E%d"%int(round(k)))	#Set new step count
			print "Steps per mm:    %3d steps"%k	#Tell user
	print 'Calibration completed.'	#Yay!
except KeyboardInterrupt:
	pass
finally:
	if p: p.disconnect()