A crude temperature logger for printers running Makerbot s3g based firmware

logtool0.py

# Tool 0 temperature logger

# DO NOT RUN THIS PROGRAM WHILE PRINTING-- THIS IS DEISGNED FOR TEMP TESTING
# USING THE PREHEAT FUNCTION AND NOT DESIGNED TO BE RUN WHILE PRINTING!

#################################################################################
# Copyright (c) 2013, jake (at) allaboutjake (dot) com
# All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#     * Redistributions of source code must retain the above copyright
#       notice, this list of conditions and the following disclaimer.
#     * Redistributions in binary form must reproduce the above copyright
#       notice, this list of conditions and the following disclaimer in the
#       documentation and/or other materials provided with the distribution.
#     * The name of the author and/or copyright holder nor the
#       names of its contributors may be used to endorse or promote products
#       derived from this software without specific prior written permission.
# 
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER, AUTHOR, OR ANY CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 
# GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 
# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

from threading import Timer
from time import sleep
from time import time
import serial
import sys

# From: https:#gist.github.com/alexbw/1187132
# Simple repeating timer implementation
class RepeatingTimer(object):
	"""
	USAGE:
	from time import sleep
	def myFunction(inputArgument):
		print(inputArgument)
	
	r = RepeatingTimer(0.5, myFunction, "hello")
	r.start(); sleep(2); r.interval = 0.05; sleep(2); r.stop()
	"""
 
	def __init__(self,interval, function, *args, **kwargs):
		super(RepeatingTimer, self).__init__()
		self.args = args
		self.kwargs = kwargs
		self.function = function
		self.interval = interval
 
	def start(self):
		self.callback()
		
	def stop(self):
		self.interval = False
		
	def callback(self):
		if self.interval:
			self.function(*self.args, **self.kwargs)
			Timer(self.interval, self.callback, ).start()

# configure the serial connections (the parameters differs on the device you are connecting to)
ser = serial.Serial(
    port='/dev/tty.usbmodem1411',
    baudrate=115200, timeout=None)

# Send a "version" packet and then flush the input as a way to synchonize the stream
ser.flushInput()
version_packet = "\xD5\x03\x00\x00\x64\x04" # Version rquest packet
ser.write(version_packet)
ser.read(1) # since timeout=None, this will wait for a response
ser.flushInput() # flush the rest.    

# This function will be called periodically to take a temp reading and output it to file
def takeToolReading(starttime):
    ser.flushInput();
    request = "\xD5\x03\x0A\x00\x02\xD6"  # Get toolhead 0 temperature
    ser.write(request)
    response = ser.read(2+3+1)

    readtime = time();

    request = "\xD5\x03\x0A\x00\x20\x49"  # Get toolhead 0 target temperature
    ser.write(request)
    response2 = ser.read(2+3+1)

    # A place for results
    temp = None
    setpoint = None

    # Parse the temperature response packet
    if (len(response) == 6):
        array = map(ord, response);
        if (array[0] == 0xD5 and array[1] == 0x03 and array[2] == 0x81):
            temp = array[3] + (array[4]<<8);

    # Parse the setpoint response packet
    if (len(response2) == 6):
        array = map(ord, response2)
        if (array[0] == 0xD5 and array[1] == 0x03 and array[2] == 0x81):
            setpoint = array[3] + (array[4]<<8);

    # Print the result
    timestamp = readtime-starttime
    print "%f %s %s" % (timestamp, temp, setpoint)            
    sys.stdout.flush()  # I like to > this out to file and then 'tail -f' it.

# Setup the repeating timer to take BHP readings
# The parameter is the start time (used as offset for time stamps)
r = RepeatingTimer(1.0, takeToolReading, time())
r.start();