Tuesday, February 12, 2013

Forcing Serial device to use the same Serial port

EDIT: Note, that this caused an error that I'm currently trying to work out. I'll remove this once I've figured it out. Basically, it doesn't treat the second device as a serial port.

Note, that I'm currently writing this to use on my Raspberry Pi to make it work better with BotQueue's client software, bumblebee. When you unplug a usb serial device, and plug it back in, the serial port changes.  So, if you have it as /dev/ttyACM0, unplug it and plug it back in, you'll see it's now at /dev/ttyACM1.

Throughout this tutorial, I'm going to use /dev/ttyACM0 since that's the current port of the device I'm trying to get to stay.  Note, that this is a device rename, not a symlink. I'll be using /dev/ttyJasmine for the new port since Jasmine is the name of my printer.

First up, let's find some info about the device:
udevadm info -q property -p $(udevadm info -q path -n /dev/ttyACM0)
It should spit out some info. The line that we need to pay attention to is ID_SERIAL_SHORT.

So in the case of my arduino, (excluding all irrelevant fields):
ID_SERIAL_SHORT=<removed for the blog post>
Now it's time to set up what's called a udev rule.  Run the following command, replacing nano with your editor of choice: (Note, that I chose 45 arbitrarily. Just for fun, you might want to research how the numbering system works)
sudo nano /etc/udev/rules.d/45-serial-devices.rules
Go ahead, and add the following line, replacing the items in < > their appropriate values.  So in my case, I'd replace <SUBSYSTEM> with tty and <ID_SERIAL_SHORT> with the serial device I found earlier. (Note, that this is all one line)
SUBSYSTEMS=="usb", ATTR{serial}=="<ID_SERIAL_SHORT>", NAME="ttyJasmine", GROUP="dialout", MODE="777"
Go ahead and save the file. After a fresh reboot, you should see your device have the name that you assigned to it.  If not, then run the following command to see what the problem might be:
cat /var/log/daemon.log | grep udev
Remember to change your config.json to use the new port if you did this for botqueue.

Saturday, February 2, 2013

Run Bumblebee on Raspberry Pi boot

In my last post, I showed you how to set up a raspberry pi with BotQueue. This time, I want to show you how to start it on boot.

First, let's create an executable script to run bumblebee with a single command. I'm doing this so that if I ever change the directory BotQueue is in, I only have to change one file. So to edit the new executable, run the following command (replacing nano with your text editor of choice. I use vim personally):
sudo nano /usr/bin/bumblebee
You should be presented with a blank file. Add the following lines to it, before saving and exiting (replacing /home/pi/BotQueue/bumblebee/ with wherever you put bumblebee. Note that you should not use ~, but instead /home/pi/):
cd /home/pi/BotQueue/bumblebee/
python bumblebee.py
After that's saved, you need to allow people to execute it. Type this to get the desired effect:
sudo chmod a+x /usr/bin/bumblebee 
Of course, you should run "bumblebee" now to see if it worked. Next up, we need to make the user automatically login on tty1. Again, I'm assuming you are using the pi user here. If you aren't then just change the username in the instructions accordingly. First, edit the /etc/inittab file. You'll need sudo permissions, of course:
sudo nano /etc/inittab
Find the line that looks like this:
1:2345:respawn:/sbin/getty 38400 tty1
Change it to this:
#1:2345:respawn:/sbin/getty 38400 tty1
And add this below that line (replacing pi with the username you want logged in and running bumblebee with):
1:2345:respawn:/bin/login -f pi tty1 </dev/tty1 >/dev/tty1 2>&1
 Good good. Now, in the home directory of the user you did that too (in most cases, that'll be your own), edit the ".profile" file. (notice the '.' at the beginning of profile):
nano .profile
At the bottom, add the following lines (If you don't care about the terminal screen going blank, leave out the setterm line):
if [ $(tty) = /dev/tty1 ]; then
    setterm -blank 0
    sleep 10
And now, just run this command to reboot:
sudo reboot
There you go. Once you have gone through a reboot, the program should be running in the main terminal window, while still giving you the ability to ssh in. The only problem with this is that you can't type things like q to quit the program. This is a problem with bumblebee, which I'm hoping to eventually fix. Although, I wrote this tutorial and the last one all over ssh, so it's completely possible to not need a keyboard on the host computer.

Monday, January 28, 2013

Raspberrry pi reprap controller with BotQueue

I've recently been interested in making my 3d printer more compact. But first, a small introduction to my printer.  My printer is a reprap prusa mendel based printer. It uses a RAMPS 1.4 board and a budaschnozzle extruder. Her name is Jasmine, which stands for "Just Another Sexy Machine, Is Notably Expensive" at the suggestion of a friend.

So, now that that's over, let's get started.  For this, I bought a PNY premium 8GB SD card for $10.  Make sure it's more than 2Gb. I did 8 just to be more on the safe side. I've installed images directly to the card before, but I wanted to try the Raspbian Installer to see how well it worked. I tried it, and it didn't install everything I wanted. Or I should say this system is probably more designed to be run as root and I didn't want that. So, download Raspbian "Wheezy" from here. Install it to the sd card using some method described on this page. It shouldn't be too painful to install.

Now then, time to install our software. Head on over to BotQueue and sign up for an account. After logging in, you'll be able to create a new account. Log in to your raspberry pi (over ssh is fine).

You'll have to log back in for the group change to take effect, assuming you had to install sudo in the first place.
sudo usermod -a -G dialout pi
sudo apt-get install git-core python-pip
sudo pip install pyserial
(If anyone can figure out how to get pyserial with this release easier than installing pip, I'd be somewhat grateful)
This will install the main core of git so we can download the repo. Now, there is the repo currently supported by Zach Hoeken here. There is also my version here. Mine fixes some problems like flickering with the raspberry pi, but you should probably use Zach's version for now. Run the first one for Zach's or the second one for mine.
git clone https://github.com/Hoektronics/BotQueue.git
git clone https://github.com/Jnesselr/BotQueue.git
Excellent! Now run these commands:
cd BotQueue/bumblebee
python bumblebee.py
It will give you a link (or open up a web browser). If it opens up a web browser, login through that window or just close it to see the link printed on the console.  This is probably a great time if you're doing this over ssh, because you can just copy and paste the link in your browser. Technically, you could have done this from the built in browser, but I didn't want to do this from a raspi. It may ask you to login. It will then give you a pin number to authorize the app with. Type the pin number on the raspberry pi.  After it authorizes, you'll be brought up to the main menu. Press q to quit.  Now go here, and follow ONLY step 4. This will add your bot to the config.json file. In the future, I'm planning to make this more automated. I'm not sure if Zach is thinking the same.

Note: You might be able to only run your bot at 115200 baud. I'm currently working on that. I think you have to overclock the pi to be able to do more than that.  I'll look into it and report back.

After that's all saved, just to make sure, restart the raspberry pi:
sudo reboot
Then, just restart the client software by running:
python bumblebee.py
Now, go back to botqueue.com, and click on "Actions" and then "Register Bot". Fill out all of that information, but be careful. The name of the bot here must match verbatim to the bot listed in your config.json file. If not, then the server won't send requests to the correct bot.

So, you should have the client software running and connected to the server. If you upload a .gcode file to the default queue, your bot should grab it and start printing. If not, check to make sure that the bot is online and idle. The program should list your bot's id, it's name, and it's status should be idle. Send it a .gcode file and let it print!

 Note: This tutorial does not cover some important security types like not permitting root login via ssh. That one can be found here.

Also note, that I am human, so there is most likely a mistake somewhere in this document. Next blog post: how to make it start up as the main tty on boot.

Tuesday, January 15, 2013


Hello, and welcome to my blog.  I decided to set up this blog to tell other people about the cool things you can do with technologies like 3d printing.

This blog will primarily contain:

  • Information about programming
  • Automated systems such as 3d printers or cnc machines
  • computer administration, e.g., linux servers
  • minecraft
  • Anything else I feel like
I hope you enjoy reading this blog and find the information within to be useful.