Day 4 – Work in Progress

Leave a comment

Being the first day of pure project development, day 4 had a very special feeling to itself. The groups dedicated themselves to the advancement of their projects, aided by the always needed help of the tutors. The Arduino platform begins to feel natural, its workings are more and more understood, and the first deeper insights are made (who knew that an output set to HIGH still differs to the permanent 5v output?).

Transistors make their first appearance, almost every group makes use of them, as they prove quite useful to close circuits when needed. The poor labeling on the transistors-box makes it more fun, as it is necessary to search for specs online to see if they are n or p switches.

Some groups have first minor or major breakthroughs, solving problems they had in a different way than previously planned.

Group 1

The Rescute team is well on their way. Solved is the problem of the spraying of the pepper spray, the LEDs are also working as planned, thanks to the additional power now used. A bit of frustration about the limited range of arduino servo motors came up, therefore effectively limiting the range of the bear’s neck. Originally it was planned for the bear to turn its head a creepy 180° on each side, now it looks like he will have to be able to turn its head 180° on one side only. Maybe hacking a servo motor will help.




Group 2

The second group works hard on its project. It proved to be more challenging than previously anticipated, as seemingly simple tasks like the compressing of a spring prove difficult to realize with the resources at hand. Thankfully, being the creative people they are, team 2 members can compensate these problems through ingenious alternatives or workarounds. For the construction of their toy train, they make use of the laser cutter upstairs, and the result is very satisfying. Nonetheless, all of this requires lots of energy and concentration from the team 2 members, leading to part of them to almost fall asleep during the lunch break.




Group 3

The togebear has seen some progress as well. The knit-work (yes, you read well, this bear is 100% handmade, something a soul-less laser cutter could never achieve) is almost done, meaning that the outside of the bear is almost ready. The inside of the bear proves more challenging than expected: when receiving an email from a loved one, the bear should spray some perfume. Using a hacked airwick system proved to be tricky, as reversing the motor rotation (it needs to go in both directions) proved an impossible task. Building an h-bridge did not solve the issue, maybe some of the used mosfet transistors where not suited for the used voltage. An hacked servo motor (not limited to 180° rotations) was used instead.




Group 4

The Looping Louie team moved to the laboratory upstairs, as they need the space and tools it offers. Probably one of the most complicated projects hardware-wise, it makes sense for them to be close the equipment. Being physically removed from the rest of the other groups makes it more difficult to judge their progress, but whenever one needed something from upstairs, she or he would hear a small Eureka shout, signaling a further success of group 4, approaching the end goal step by step.




Group 5

Today post arrived for the Madlab group, it was the game they are going to hack. Finally having the game, they were quickly able to make some progress. Surely it did help, that they didn’t lose time the previous days, thinking ahead of what and how to do it. Servomotors were quickly attached to the game, LEDs were tested, boards altered. Group 5 may have had a delayed start due to the late arrival of the game board, but they managed to make up for the time lost, and then some. If they keep up with this pace, they will be out of work by monday.




Group 6

The Ghostcamera team had some important hardware arrival as well, now having a functioning printer for their project. The idea is to have a camera take a picture of you and then print it, but with one twist: the printed picture will have some sort of monster on it, be it a ghost or zombie, or whatever. This surely has to be the most complicated project from a software point of view, but the team members are concentrated and seem very confident about the outcome.




All in all it was a very productive day. Each team was able to make significant progress, each team already faced problems, some of them are already solved. Creative thinking seems to be the key here. The lesson learned today seems to be not to give up immediately, but also not to fixate on one approach. If something does not work after scrupulous researching and trying, then it is time to think of a different solution to the same problem.

Another important aspect of today, was the fact that we really got our hands dirty, and quite quickly. Almost every group used power tools like power drills, dremel or power saws, as well as special machinery like the laser cutter. These are tool that some of us used for the first time. It became quite clear, that this course would not be completed by simply putting some lego together, but that custom work is necessary.

Even the components used in our electrical circuits became more sophisticated. If there was the idea that sketching with hardware could be completed by simply putting some pre-made components on a bread-board, after today the reality became clear: it is much more than that. We finally understood the importance of transistors and switches. It is one thing to read about them in a chapter of some lecture where they are mentioned briefly, but it is a totally different thing to understand how they work in order to use them in our projects. If we want to power some LEDs with an additional power source, how can we control this source? Transistors! If we want to make a motor rotate in 2 different directions, without physically switching cables, how do we do that? Transistors! Thankfully the tutors were there to answer our questions, an we all had some, ranging from where can i find xyz to more technical ones.

This was a very long day, but thankfully the weekend awaits, and monday the show will go on!

Day 4: Let’s build ’em prototypes!

Leave a comment

As of day four, the time has come for the six teams to rack their brains about fiddling around with the prototypes using the ideas gathered through the brainstorming sessions the week before. The sun, still pounding its seemingly endless heat into our lab, was only partly repressed by installing and building our own fans (why not use our newly gained know-how?)  🙂

However, the heat couldn’t impede our evolving progress on the prototypes:

Team 1: Mastering the Solderings

Working on their digital audio workstation and music sheet reader, a lot of soldering for the light sensors had to be done.

Throughout the day, this task has been accomplished with great satisfaction. Also, after some smaller obstacles with a magnetic fixture for the toaster handle, there have been great results with the light sensors and cable spaghetti management.


Result of the day: Light sensors, LEDs and nice cablework.


Light sensors, LEDs and Arduino attached to the Midi-Toaster

Sarcastic yet humorous comments from our team lead like “You like to switch the negative and positive pole, don’t you?”, “Some electrical shock could be a good lesson” didn’t spoil the moods. 🙂

Team 2: Mutilate that Teddy Bear!

For a cyborg teddy to be born, it first had to be sliced into pieces.

While it seemed that today’s birthday girl had lots of fun chopping off that teddy’s head and pinching out its eyes in order to fill it with electronics, some problems also emerged. Hacking an old mp3-player’s buttons turned out to be easier said than done: finding the right current and producing good sound proved to be quite strenuous. Towards the end of the day, however, starting and stopping the mp3-player via pressure sensors was already possible.

Having to spend her birthday in the lab, she let her aggressions out on the poor teddy bear

Having to spend her birthday in the lab, she decided to let her aggressions out on the poor teddy bear











Team 3: Microengineering

Team “Walkman remote” now rustled up some sickly looking vintage Walkman. After disassembly, there has been a lot of struggling trying to fit all necessary components and cables into its relatively tiny case. Furthermore, translating the Walkman’s buttons and switches to address Arduino’s logic showed to be kind of a hassle.

Vintage Walkman

Vintage Walkman

Trying to get all up and running with Arduino

Trying to get all up and running with Arduino

Team 4: Refunctioning an Oscillograph

In order for their old oscillograph to reveal its great, gear filled look inside the case, team 4 decided to design and laser cut some acrylic glass to a new, now transparent part of the chassis. Requiring 4 attempts to do so, this design task turned out to be the main focus point of the day. After all the trouble, it showed to be worth the effort. Furthermore, it is now possible to control the newly attached servomotors through the connected joystick.

A sketch for the new chassis part to be laser cut

A sketch for the new chassis part to be laser cut

Controlling the servomotors in the oscillograph with a joystick

Controlling the servomotors in the oscillograph with a joystick

Team 5: Raspberry vs Windows; Python vs. Team 5!

Bright prospects in the morning: Authentification and uploading files on dropbox through a Python script works!

Since Arduino Uno is not quite capable of handling all the data coming from a scanner, its competition “Raspberry Pi” was to take its place. After quite a while of installing Raspbian, this slim Debian derivate disappointed by lacking support for the scanner. Therefore, good ol’ Windows XP on an Eee-PC had to do the job.

Afterwards, the wrestle with necessary Python modules, their different required Python versions and promising though non functioning “Easy-Easy Installers” from the depths of the WWW took the rest of the day until 7:30 pm.

Software installing sessions

Software installing sessions

Having Raspberry up and running

Having Raspbian up and running

Team 6: Fully Charged Capacitor + Curious Adrenalin Junkie = Sensational Short

Capacitor 1 :  0 Student.

This big capacitor definitely won one curious student’s respect today. While experimenting with this at first seemingly harmless piece of electronic in order to get the flashgun to work, the capacitor impressed by creating its own noisy flash when shorted. 🙂

Besides making this involuntary experience with electrical shorts, a lava lamp has been boiled and disassembled, and an accelerometer and an EMG-chip have successfully been soldered and addressed for the arm muscle tension-measuring wristband.

Fun with the evil capacitor

Fun with the evil capacitor

Trying the EMG-Chip for the Wristband

Trying the EMG-Chip for the Wristband

Day 4: The building phase begins

Leave a comment

The fourth day mainly consisted of building prototypes for the projects. There was no schedule for the day, so each group was free to manage the time on their own.

After the project ideas were set on Monday, for most of the groups the main target for the day was to verify the technical feasability of their ideas. For each project, that meant a different challenge. Mostly, that was to get a working circuit with the intended functionality on the breadboard.

Due to the diverse nature of the projects, a lot of different technologies were explored. From Wi-Fi to Xbee wireless transmitters, GPS, Motors and a lot of different sensors, each group had its own hardware set to tinker with. Even the smell of the laser-cutting machine was noticeable a few times the day.

While building the prototypes, it got obvious that some ideas didn’t work out as expected. Hence, two groups changed their project topics for the sake of better feasability. After all, it seemed to be a successful and funny day for everyone, thanks to Hendrik’s extensive support.

For most of the groups the lab day ended at 5, while some eager groups tortured their Arduinos till 8 in the evening.

Day 4: Ready, steady, go …


9:00: We are finally getting started! Everyone is busily gathering boards, resistors, capacitors and cables, unpacking newly arrived components or hurries away to buy those parts that are still missing. Some groups even seem to plan to integrate unusual components such as umbrellas, inflatable mattresses or small plastic bubbles into their prototypes.

13:00: How to solve  problems, you did not know existed? The more our concepts are progressing, the more challenges have to be faced. Some basic solutions for often occuring problems:

How to connect RGB LED strips?

1. Connect the strip.  You find four wires attached to the copper tabs. In our example (left picture below) we have from left to right:

  • white coating: green LED color
  • yellow coating: red LED color
  • black coating: red LED color
  • red:  +12V

Some ready-bought LED-strips already use color coding for the wires: white for the power supply and then red, green and blue wires for the corresponding LED colors.

rgb stripe 2     rgb stripe 1

2. Set up the circuit. As our LEDs require more power than the arduino’s build-in power supply can provide, we have to connect an external power source and therefore need to add transistors to our circuit. In the setup used for the GLOW WORM LOVE project (right picture above), three N-channel MOSFETs for each single LED are used, which allows to actuate R, G, and B seperately.

circuit setup

[picture from: ]

3. Control your LEDs

In the Arduino sketch for every LED, the channels are defined:
void setup () {



and can now be assigned seperately to a specific value. For a nice purple we can use

analogWrite(REDPIN, 112);
analogWrite(GREENPIN, 0);
analogWrite(BLUEPIN, 112);

How to convert the sensor output of a LilyPad Temperature Sensor to  °C?

Usually it is sufficient to retrieve the raw values from the LilyPad Temperature Sensor, but sometimes, for example when you are designing user interactions, you would like to know the exact value in degree Celsius. So this is how you do it in your android-sketch:

1. Read the sensor output.
temperature= analogRead(yourInputPin);

2. Convert the achieved value to volt
voltIN = 3300;  //if you connected to 3.3V
voltIN = 5500; //if you connected to 5.5V
float voltOUT = temperature * (3300/1024);

3. Calculate the
factor =  19,8;  //19,8 mV per degree, if you are using a  MCP9701A
factor = 10,0; // 10 mV per degree, if you are using a MCP9700A
float tempC = voltOUT/faktor;

How to switch the direction of a DC motor?

For the blowfish group it is important to have a DC motor capable of switching its running direction. Therefore a circuit with relays is necessary. In fact, two relays are used. One to stop the motor and one to switch the current flow. The basic idea is to use a DPDT (double pole double throw) relay which separates two differently polarized circuits. Without activating the relay, the motor is +/- connected. When voltage is applied to the relay (the switch inside changes its position) the motor gets -/+ connected and runs in the opposite direction.

relay circuit

And some further creative workarounds for so far unknown challenges had to be found.


19:00: Time to go home. All five teams have already made substantial progress and the first premature prototypes are moving, blinking andmaking all kinds of nice sounds and less nice noises.

Some impressions:

led ball  team_work  umbrella1  umbrella 2

Day 4: This is where it starts

Leave a comment

Startup Slideshow

Short one-slide presentations opened the fourth day of the course. Each team had prepared a sketch of their project’s basic concept to show to the others. If you’re interested, you can view them here:

Team 1 | Team 2 | Team 3 | Team 4 | Team 5 | Team 6

Some discussion about what to do first and what could possibly go horribly wrong followed. Luckily enough, it soon became clear that atomic explosions were not to be expected – for now. And that was it with preparation – now let the work begin!

Workshop Workout

The rest of the day we spent working on our circuits, mechanical elements, insanity and so on. Some of us went shopping to get missing parts, some others spread out through the institute’s builduing looking for a drilling machine or whatever vital tool seemed to be severely lacking in existance. Overall, a buzz of creativity sweeped the rooms. It was only broken by (mostly) silent curses, shouted test-activations of audio sensors and the cracking of an old printer being torn apart, salvaging its precious, precious motors. You get the impression.

Resting for now

At the end of the day, several prototypes grew in size, complexity or both. We’re still waiting for that special moment when someone would shout “Eureka!”, but we have already heard a fair share of various non-greek exclamations. A bit worn out, we dropped our soldering irons and laser printers (not literally of course) and let the heat and dust settle in the workshop. Now, to bed, and then: Onwards to the next day!

Let the projects begin!

Leave a comment

In medias res – we started!

Since this morning we are actually working on our projects which each team has to complete until Friday, 1 pm.So each team is strongly motivated and very concentrated on their jobs and everyone has a special task which has to be completed after that day.

In the morning, we brought all the electronic stuff we could use to our lecture room, so our work environment looks like a little scrapyard.

Each team started immediately with its work and it seems like everyone has fun and a high interest to reach the personal goal.

Here are some impressions of the work of each team and our atmosphere in which we are progressing our idea of a new communication form.

Team 3 is working with their “ROBOCAT”

Not only electronic components are important, but also raw materials like wood.

The first steps of the new Coffee-meeting-machine

And this will be a new way to coordinate the free time activities.