replacing the sensor of a dehumidifier:
the humidity sensor modules of a dehumidifier kept failing, and no replacement is easily available anymore.
after reversing its communication protocol, I was able to create my own module.
building a remotely controlled flashlight:
For another attraction held during a Halloween party already mentioned in episode #025, I also built a flashlight which can be remotely controlled.
This is ideal to put the participants in complete darkness and have glowing clowns chase them.
For this I added a tiny micro-controller and IR receiver in off-the-selves flashlights, and used a camera shutter remote control.
We will see how to deal with the size constraints using parametric search.
For more details about the Halloween party and infra-red theory, watch episode #025.
building a remote controlled strobe light:
For an attraction held during a Halloween party, I built a device which allows to send strobes of light.
Combined with a ghost apparition, this was the ideal setup for a scare jump.
The strobe controller uses an LED flood light, a solid state relay, and an infrared remote control.
We will see what mechanical and solid state relays are, how to operate them, how infrared remote controls work, and how receive decode their signal.
The Halloween party is called Balloween. It take place in Paris, and is mainly French. An entrance fee is required, but it barely covers the cost of the consumables. I and all the staff helped in our free time and at our own expenses, but it is a lot of fun and nothing beats scaring innocent victims ;).
P.S.: To create light strobes a stroboscope might be the more appropriate, but I did not have one at the time I built this device. I am also not sure how I would control the couple of kV required to fire the flash tube. Flood lights are more ubiquitous, and can also be switched on continuously.
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.