Here is how to setup the printer:

1. connect the printer to power and to the PI (via USB)

2. install cups and the printer driver on the pi:
sudo apt-get install cups printer-driver-ptouch

3. set up user rights:
sudo usermod -aG lpadmin pi
This steps enables you to access cups administration pages in the next step

4. install the printer in cups:
– open a browser and go to http://localhost:631
– when asked for a password use user “pi” and password “raspberry”
– add a new printer, select the QL570 which is locally connected
– use the driver for QL550 when asked for the driver you want to use

5. finish – enjoy printing

At work I needed to distinguish between five tty devices in linux, which in this case were almost identical FTDI to TTL UART adapters.

I thought of using udev rules for it and give each one a specific name in the file system based on the FTDI device id/serial number. Fortunately I found an easier solution: you can access the device not via /dev/ttyUSB0 through /dev/ttyUSB4 but via /dev/serial/by-id/usb-FTDI_FT232R_USB_UART_AD023MTX-if00-port0, which is a symbolic link to the corresponding /dev/ttyUSB*.

To match the tty device to the physical device I needed to collect all serial numbers of the adapters. In the above example this is AD023MTX. I found this serial number out via executing udevadm info –name=/dev/ttyUSB0 –attribute-walk, where you need to look for a line beginning with ATTRS{serial}.

The common solution until now is to export your board with eagleUp and assemble it with a case in Sketchup. This also gives you some drawbacks. The most important to me was that the Sketchup files are mesh based like the data used for 3D printing usually, but for further use in CAD systems this is not really usable. You also will not be able to get a STEP model that you can give to your costumers out of this data.

Another solution is to use eagle3D, which gives you photorealistic renders of your boards. This images (or even videos) are really good for marketing brochures, but this way makes it impossible for you to play with your 3D models to estimate how much space is left in your case.

The solution I found was to write a macro for FreeCAD that interprets the XML Data that Eagle 6 uses to save your board (the .brd file). This means that my script reads the outline of the pcb and extrudes it with the thickness you specified in eagle. The XML file also contains the names of your parts, which you can map to 3D CAD Models (STEP Models) of them. The last step is to assemble the parts and the board. For more information on how to use it see my github repository.

The only drawback of the freecad solution is that somehow the colors of STEP models get lost – at this time I expect it to be a freecad problem that might be fixed in the future.

The result looks amazing:

Thanks to my boss Carsten Ziermann, who allowed me to make changes on the script in my time at work as well as to use the screenshot above.

I had a lot of experimenting with the belt tension and the endless settings for the slicer software. But finally I got it working. The printquality is not perfect – but I will tune it later for a better print quality. When I have final settings they will be published – but this might take some more time

For those who do not know 3d printing well: the layer below the cylinder is called “raft” and it is used to get an flat surface where you can print at. The second use of this is to prevent the printed object to stick to much to the printing platform.

I wrote some more about it in an article here: http://avrs-at-leipzig.de/dokuwiki/en/prokekte/fluxprobe

If you do not like to open the full arcitle here you can review the basic schematic as well as to see a foto of my first prototype:

The first but still impressing measurement:

The following video shows the first quasi autonomous movements of my 1:8 sized buggy. I wrote a little script that makes movements suitable for turning the car.  I had no space in my flat for letting it run right now so I stuck with the ‘dry run’ for now. After adding some more sensors I will replace the script to be event driven instead of timer based.

The electronic components are: Toradex Colibri T20 on an Iris carier board running Linux (I got that one at embedded world this year) and an Arduino for controlling the servos. There also is a DC motor controller for driving the wheels that came with the car.

As in my last post I have shot timelapse videos to show you the progress:

I connected all the motors, the heater and the thermosensor to the printer. Surprisingly all the axes were working instandly. Unfortunately the heater and the sensor were not working at all and the stepsize of the motors seem not to fit. Als I have to attach the end stop sensors to the printer for the Gen6 hardware… This means it will take some more time until I finally can print

At some points you can see me confused for some time and putting unfinished modules aside. This is because a few parts were missing… John got back to me over the night and promised to send the missing parts out today. Well, that means I will wait for these parts to arrive for one or two weeks. In this time I can also order some other missing things like plugs for the motors and glue to hold the temperature sensor in place.

Here is a picture of the machine how it is looking at the moment – without any adjustments because I will have to take some parts out again:

The final day of the exhibition “embedded world” was a bit less exhausting. We spend some time speaking to the people of the stand linux meets industry. This organisation is supporting big companies running and developing open source software as well as spreading the open source thinking.

The rest of my day was quite relaxed… we walked around a bit and talked to several companies as well as some people who were interested in the project leobots.

All in all the exhibition was a big success for the team as well as for me. We all got some great impressions what the embedded industry is like at the moment.

Today I spoke to some companies that I might work for in saxony. There are quite a lot of them, that I did not know before or I did not know that they also develop hardware themselves. This is why today was a great success for me. But on the other hand the days get more and more exhausting – fortunately the exhibition ends one hour earlier tomorrow. I’m very tired right now…

After the official end of the visitor opening times there were some parties at the microsoft and ebv stand among others. Thanks to them for providing some food and drinks for us while playing music! Also thanks to the “open source meets industry” guys who are always worth talking to! Especially I was enjoying to meet Benedikt Sauter (http://embedded-projects.net/) finally after following his work since several years now.

One thing I want to show you finally is an automatic solver for the rubik cube. Basically they built a lego mindstorms robot that handles all the turning and used a smartphone to capture the recent state of the cube. These two elements are combined by a pc that solves the game and controlls the robot while capturing the images form the smartphone: