Sonntag, 1. November 2015

Haunted Fish Tank


Hi all,
I want to present my Haunted Fish Tank. It is based on the Peppers Ghost effect. The Glass inside the box is reflecting the Screen from the upper part and the animals and other stuff seem to float in the air. Like Ghostfishes.

It's verry difficult to capture the effect on video.

The Plan

The Box

I used 6mm MDF wood panels, and glued and screwed them together.
The cover has 4 big holes, for aeration.

First, I painted the inside of the box black
On the outside I glued half wooden balls to make it look like rivets.

With wooden spatula I made the surface rougher. I used wood glue to write the text on the front. Now let it dry for min. 24 hours. Then I painted the outside black and again I had to wait for 12 hours.

I used copper color and a soft cloth to make it look like an old box made of copper. In the aeration holes I glued fly screen pieces.

The Screen

An old 15 inch screen with scratches
I took An old 15 inch screen,with scratches, apart and I added a power connector for the Led's The original buttons were fixed on the backside of the monitor.

Leds and Decoration

In the middle part, where the monitor will be fixed, I drilled 5 x 10mm holes and glued 10mm blue Leds in.
I used 2 Red, 2 Blue and 2 color changing Led's and glued them with hot glue in the shells. All wired and glued on the bottom of the box. Then I added white stones.

A few skulls, plastic plants and a little statue in the middle, to build the scenery.

Video Editing

I projected a grid on the screen to mask out all the decoration.

With the objects masked out, I can decide if something is in front or the back.

The Creatures were created from 2D Images. They were edited in Gimp. The fin is animated in Vegas Pro. The Contrast for the animations is nearly set to maximum.

The monitor is reversed, so the video has to be upside down.


Place the glass sheet in the box. Insert the middle wood plate with the electronic. An old 5W Speaker and a 3,5W amplifier for the sound. I added a 10k potentiometer for the volume.

Place the LCD on it. A little piece of breadboard with connectors to supply the 12V for the LEDs and the audio part.

Finally put the cover on it.

Now connect the Laptop, PC or Raspberry to it and play the video file.

Happy Halloween :)

Donnerstag, 27. August 2015

RaspiTrap V1.0


Hi all,
I want to present my Raspberry Pi project.
An animal friendly mousetrap with photo, video and email function.

You may ask, why somebody would build such a mousetrap?
Why not?

C.A.D. Design

First of all I tried the design in Sketchup 8, which is still free
I could try a few designs virtually to see if everything fits.


To build the housing (350mmx110mm), I used 5mm foamed PVC Sheets.
So, I could use a cutter as CNC machine :)

Infrared Barrier

To detect if a mouse is inside, I made an infrared barrier.
It was build on breadboard for test, but I was too lasy to make my own PCB, so I ordered it in China.
It took one week and the result is stunning.
I want to use an external power supply, but I decided later, to use the 5V from the raspberry pi.

Transmitter and Receiver

To fix the IR sensors TEMIC K153P inside the trap, I manually milled two grooves.
They were placed behind the 3mm acrylic glass plates.
As you can see, the 9gr. servo motor is already mounted.

Pi Camera with Fisheye

I used a cheap fisheye lens to mount in front of the pi camera.
For mobile phones these lenses are fine, because the phones have an autofocus.
The pi camera has a fixed focus so that the picture is blurry.
I will try to change the focus on the pi camera, but not for now.


The scrips are written in python.
The trap software has the start script. Basically, this one just checks if the end switch is released, and then jumps to the main part.
In this one, we check if a mouse is detected by the infrared barrier and then it jumps to the script which takes a Photo and sends the Instant message. After this it jumps to the one who sends the mail.
For the instant messaging I use Instapush (

Everything in Place

At the back side you will find the Raspberry Pi, the servo motor and then PCB for the Infrared barrier
The release mechanism on the left side is a thin piece of PVC. It is connected over a thin metal bar with the servo motor. Behind the servo is an end switch. This one detects, when the trap was released.
Inside the trap is white LED. It shows me the status of the mousetrap and it is used as
flashlight to take the pictures
The raspberry runs on archlinux.

Things to add:

-Web server with live view
-Even if the trap is not airtight,
I will add a few air holes in the cover

Last Words

No animals were harmed during these tests.
In the trap is always enough food and water for the mouse, to survive until it gets released.
All the mice, I had caught, are free again and on their way home

Thanks for your interest