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This is my workshop, seen from the street. It is located in East Berlin. Before 1989, it was a fish shop. After the breakdown of the GDR, it was used as a porn casting office, and now, I am living and working here.


When the people pass by, this is what they see from the street. I have a lot of curious visitors, which come in and ask me what I am doing here. The number of visitors increases dramatically, if strange things happen (like wheelchairs that drive around automatically).


Here are some pictures of the parts, on which I worked during the last weeks: The finished Line Detection Unit #2.


A close up of the device.


Here, you can see quite nice, how it works. The device is mainly built out of PVC. There is an LDR in each of the holes, and in the slot next to it, there's a cold cathode tube, which lights the floor. To keep a certain distance to the floor, I am using two brushes out of a vacuum cleaner.


Without the aluminum cover, you can see all the resistors. Each sensor consists of a voltage divider, built with a 1K resistor and one LDR. The yellow transformer on the right side produces the 800V for the cold cathode tube.


The same thing from another perspective.


... and a little bit closer.


This is the back of the wheelchair.

1&3: Additional boards for controlling motors, which are mounted inside the seat (to adjust the back of the seat, the height of the seat, ...) Both boards have two relay h-bridges for two motors. The communication with those boards seems to go via I ²C.

4: This small relay board is connected to board #3. I haven't found out, yet, why the wheelchair needs this additional board. However, it seems to drive the motor which adjusts the height of the seat.

2: This is the main board. All connections go over this board. plug #6 is going to the control unit (it is one of the strange sub-d plugs, that I described in march 2006)

5: I have added this heavy duty relay. It is connected to the emergency off button and breaks the whole power supply, if I push the button.

7: This is the "dynamic controls" motor driver. I haven't opened it, yet. And it seems, that I don't need to, because everything works well, so far.


This picture was made, when I was hacking the wheelchair. I jacked it up, to perform all its functions, and with the oscilloscope, I watched which wires and voltages control all the different functions.


Here, you can see the two 65Ah car batteries.


When I've built the first circuit to produce the two control voltages of the wheelchair, I had the idea to draw on my oscilloscope with that circuit. So I connected one voltage to the x-axis and one to the y-axis, and voilà, I could draw nice pictures on the screen.


Later, I also animated this car. Unfortunately, I can't show this on the photo.


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