SisterAlarm

Do you have a sneaky snooping little sister or brother?

View project on GitHub

The Princess Ophelias Sister Alarm

Do you have a sneaky snooping little sister or brother? We know you always want to keep them out of your room with the most high-tech solution available.

The following is a tutorial project for building a motion sensor based alarm that is activated/deactivated with an RFID card / tag. It should be suitably loud and annoying to your snooping little friend.

PSB labels

Usage

The SisterAlarm has two states, engaged and disengaged. In its engaged state, any input from the motion sensor will trigger the buzzer to make loud, obnoxious and annoying noises to scare away your sibling, and to alert you to come to the scene to save what can be saved of your belongings before they are stolen, whacked or eaten (depending on the age of your… problem).

In its disengaged state, it allows you to reside in your room without triggering the alarm.

To switch between the two states, you swipe your RFID card or tag over the reader. The display will announce the new state.

If an invalid card (e.g. a random bus card your annoyance have found) is swiped while in the engaged state, the alarm will immediately activate, screaming for you to come handle attempt to hack your security system.

Finally, we would like to point out that it’s obviously trivial to change the texts displayed on the display in the different states and for the various events. Actually, we encourage you to do so to properly scare off your sibling, or just plainly state their unwelcomedness!

Ingredients

Main ingredients

Arduino

Peripheral ingredients

(all from Luxorparts)

  • RFID reader RC522
  • LCD screen SH1106
  • PIR (motion) sensor
  • Active piezo buzzer module

RFID Screen PIR BUZZ

Instructions

Start by labeling your PSB this way:

PSB labels

Okay, so this might sound quite techinical at first, but hang on, it’s actually pretty simple to get it working:

The PIR (motion) sensor connects to a single digital input pin, and the piezo buzzer to a single PWM digital output pin.

The screen connects via I2C (SDA & SCL signals), and the RFID reader via SPI (MOSI, MISO, SCK, SS) and RST.

All the modules are sold with labeled pins, so all you need to do is actually to wire them up to the correspondingly labeled pins on the PSB! Then do the same with the Arduino. The PSB has separate labels for the arduino pins. Don’t forget Ground and 5V (VCC).

Some notes though: The RFID reader we got wants 3.3V, not 5V. You’ll have to run an extra cable just for this, directly to the arduino:s 3V3 pin. Be carefull!

Software

You need to program your Arduino to turn it into a SisterAlarm Main Unit! To do so, first download and install the prerequisite Arduino libraries listed below, then download the SisterAlaram.ino and load it in your Arduino IDE, connect the Arduino USB cable and press “play”.

Prerequisite libraries

  • MFRC522 (install using the Arduino IDE: Sketch / Include libraries / Managa libraries)
  • MicroLCD

Comments

It’s a bit unfortunate that the screen and RFID reader connects via different busses, but these are the most common components available. If you can find ones that share bus you could simplify the cabling a bit!