Jake B. / Mbed 2 deprecated MakerBotServer

A web server for monitoring and controlling a MakerBot Replicator over the USB host and ethernet.

Dependencies:   IAP NTPClient RTC mbed-rtos mbed Socket lwip-sys lwip BurstSPI

Fork of LPC1768_Mini-DK by Frank Vannieuwkerke

Makerbot Server for LPC1768 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.

Warnings:

This is not a commercial product or a hardened and secure network appliance. It is intended as a thought experiment or proof of concept and should not be relied upon in any way. Always operate your 3D printer in a safe and controlled manner.

Do not connect this directly to the exposed internet. It is intended to be behind a secure firewall (and NAT) such that it will only accept commands from the local network. Imagine how much fun a hacker could have instructing your 3D printer to continually print Standford bunnies. Well it could be much worse then that- a malicious user could send commands that could crash your machine (both in the software sense, as well as in the "smash your moving parts against the side of the machine repeatedly sense), overheat your extruders, cause your build plate to catch fire, and do severe damage to the machine, any surrounding building and propery. You have been warned.

Never print unattended and be ready to step in and stop the machine if something goes wrong. Keep in mind, a 3D printer has heaters that are operating at high temperatures, and if something starts to burn, it could cause damage to the machine, other property, and/or hurt yourself, pets, or others.

You should understand what you are doing. The source code here is not intended as a finished product or set of step by step instructions. You should engineer your own solution, which may wind up being better than mine.

Proceed at your own risk. You've been warned. (Several times) If you break your Makerbot, burn your house down, or injure yourself or others, I take no responsibility.

Introduction

I've been working on a side project to solve the "last mile" problem for people wanting to print from the network on their bots. I feel like the first half of the problem is solved with the FlashAir- getting the files to the card. The next step is a lightweight way of sending the "play back capture" command to the bot.

I looked around for a microcontroller platform that supports both networking and can function as a USB host. I happened to have an mbed (mbed) on hand that fit the bill. The mbed also has a working online toolchain (you need to own an mbed to gain access to the compiler). Some people don't like the online development environment, but I'm a fan of "working" and "Mac compatible." It was a good start, but cost wise, you would need an mbed LPC1768 module and some sort of carrier board that has both USB host and ethernet, or rig up your own connector solution. I happened to also have a Seedstudio mbed shield carrier board. This provides ethernet and USB connectors, but is another $25, putting the solution at around $75.

I also had an LPC1768 development board here called the "Mini-DK2". It has a USB host and a wired ethernet connector on board (search ebay if you're interested). It's a single-board solution that costs only $32 (and for $40 you can get one with a touchscreen) Its the cheapest development board I've seen with both USB host and an ethernet connector. I considered RasPi, but I'm not on that bandwagon. Since I had the Mini-DK2 on hand from another project that never went anywhere, I moved from the mbed module and carrier board to the DK2.

The mbed environment can compile binaries that work on the DK2 (again, you need to own at least one 1768 mbed already to get a license to use the compiler), and the mbed libraries provide some nice features. A USB Host library and and Ethernet library were readily available. The USBHost library didn't quite work out of the box. It took some time and more learning about the USB protocols than I would have liked, but I have the board communicating over the USB Host and the Makerbot.

Changes to stock mbed libraries

Many libraries are imported, but then converted to folders as to unlink them.

mbed provides a USHost library that includes a USBHostSerial object for connecting to CDC serial devices. Unfortunately, it did not work for me out of the box. I spent some time learning about USB protocols. One good reference is [Jan Axelson's Lakeview Research](http://www.lvr.com/usb_virtual_com_port.htm) discussion about CDC.

I found that the stock library was sending the control transfers to Interface 1. From what I understand, the control transfers needed to go to interface 0. I modified the USBHostSerial library to correct this, and the serial port interface came to life.

Next, I found that I wasn't able to get reliable communication. I traced it to what I think is an odd C++ inheritance and override problem. The USBHostSerial class implements the Stream interface, allowing printf/scanf operations. This is done by overriding the virtual _getc and _putc methods. Unfortunately, and for a reason I can't understand, these methods were not being called consistently. Sometimes they would work, but other times they would not. My solution was to implement transmit/receive methods with different names, and since the names were different, they seemed to get called consistently. I'd like to learn exactly what's going on here, but I don't feel like debugging it for academic purposes when it works just fine with the added methods.

Usage

Connect up your chosen dev board to power, ethernet and the USB host to the Makerbot's USB cable. The Mini-DK uses a USB-OTG adapter for the USB host. If you're using a Mini-DK board with an LCD, it will inform you of it's IP address on the display. This means it is now listening for a connection on port 7654.

If you are using an mbed dev board, or a Mini-DK without a display, the message will be directed to the serial console. Connect your computer to the appropriate port at a baud rate of 115200 to see the messages.

Use a telnet client to connect to the given IP address at port 7654. Telnet clients typically revert to "line mode" on ports other than 21. This means you get a local echo and the command isn't sent until you press enter.

Once connected, you can send the following commands:

A <username>:<password> : Set a username & password for the web interface and the telnet interface. Use the format shown with a colon separating the username from the password.

V : Print the version and Makerbot name, as well as the local firmware version (the Makerbot_Server firmware as discussed here).

B <filename.x3g> : Build from SD the given filename. According tot he protocol spec, this command is limited to 12 characters, so 8.3 filenames only.

P : Pause an active build

R : Resume active build

C : Cancel build- note that this immediately halts the build and does not clear the build area. You might want to pause the build first, and then cancel shortly after to make sure the nozzle isn't left hot and in contact with a printed part.

S : Print build status, tool and platform temps

Q : Quit and logout

The Mini-DK has two onboard buttons (besides the ISP and reset buttons). Currently one button will trigger a pause (if the Makerbot is printing) and the other will resume (if the Makerbot it paused)

Compiling

Edit "Target.h" to set whether you're building for an MBED module or the Mini-DK2

Installation

If you are using a mbed, then you can simply load the BIN file to the mbed using the mass storage bootloader. The mbed mounts as if it were a USB thumbdrive, and you copy the BIN file to the drive. After a reset, you're running the installed firmware.

The MiniDK has a serial bootloader. You connect to this bootloader from the "top" USB connector (not the USB host one). Hold down the ISP button and then tap the reset button and then release the ISP button to put it into programming mode. I use [lpc21isp](http://sourceforge.net/projects/lpc21isp/) to load the binary. The other option is FlashMagic, which uses HEX files, so you'll need to use some sort of bin2hex utility to convert the firmware file if you use this utility. I can't really say if/how this works, as I don't use this method. See this (http://mbed.org/users/frankvnk/notebook/lpc1768-mini-dk/) for more info.

Credits

Some credits, where credit is due.

EthernetInterface - modified to include PHY code for both the MiniDK2 and MBED based on selected #definitions

Mini-DK - Thanks for Frank and Erik for doing all the heavy lifting getting the MBED compiler and libraries and peripherals working on the Mini-DK2

NTP Client - Thanks to Donatien for this library to set the clock over the network

RTC - Thanks to Erik for the RTC library. I've got it in my project, but I don't think I'm using it for anything (yet).

SimpleSocket - Thanks to Yamaguchi-san. Modified slightly to take out references to EthernetInterface::init() and ::getIPAddress(). For some reason these don't like to be called in a thread.

JPEGCamera - Thanks again to Yamaguchi-san. Modified to output the JPEG binary over a socket rather than to a file descriptor.

USBHost - modified as noted above

IAP - Thanks to Okano-san. Pulled out of the Mini-DK folder so that I could link it back to the base repository at the root level.

back to code example - library is at separate page