reversing washing machine payment cards:
To use the washing machines in my apartment complex you need to pay using a rechargeable contact card.
I was curious to find out how it works. It turns out it's an I²C EEPROM in a card.
By recording the communication between the card and the machine I figured out where and how the credit value is stored.
Now I can read and write the value on cards using a Raspberry Pi or simple micro-controller, but also program my own cards to work with the machines.
building an electronic cat repeller to guard the fridge:
My sneaky cat can open all doors, even the fridge door. No meat is safe any more.
To prevent that I built a cat repeller using an Atmel ATmega328P Arduino Nano 3.0 board.
An HC-SR501 PIR motion detector checks if the cat is nearby. Then an E18-D80NK range detector verifies if the cat is in front of the fridge.
If this is the case a ~24 kHz PWM signal will generate an ultrasound using a piezoelectric diaphragm, encouraging the cat to leave the premisses.
If it still opens the fridge, a human audible alarm will sound until it is closed.
LED strip based light installation:
Using LED strips, an ATX power supply, and a custom board I created a nice and bright light installation for my room.
Using infra-red LEDs I re-implemented the LaserTag protocol MilesTag v2.
With that I made an LaserTag grenade by putting a custom board placed in a cock shell.
I found out the weight measured by a Korona KFW-55 bathroom scale is encoded using PWM.
Using a micro-controlled I can interpret this value and send it to a computer over USB and bluetooth.
MegaCode is a system provided by Linear LLC for controlling gates.
This time I looked a the receiver.
With my firmware it is possible to efficiently record the individual codes of other remote controls.
MegaCode is a system provided by Linear LLC for controlling gates.
Using software defined radio I could record and decode the radio transmission of the remote.
And thanks to my firmware this can be re-transmitted.
With it is is possible to clone MegaCode remote controls.
