A system that will alert when someone is trying to steal cookies from a jar without asking for permission!
The alert system is based on the use of two sensors, Photoresistor and Force Sensitive Resistor, with a red LED as the visual feedback.
The circuit includes:
● Spark Microcontroller
● Jumper Wires
● A 1kΩ Resistor
● A single color LED
● Two 10kΩ Resistor
● A Photoresistor
● A Force Sensitive Resistor
When the top knob of the cookies jar is touched, the Force Sensitive Resistor which is embedded in the top knob will be trigger, and as the lid is being lifted, the Photoresistor would also be activated. These two sensors combined would set off a warning to the cookies jar owner, informing the owner that the safety of the cookies has been compromised!
Meanwhile, when the owner wants to eat a cookie in the jar, the owner could avoid tipping off the alarm by not touching the top knob, but lift the lid by holding the whole top instead. Bon Appétit!
The coding has been done based on the foundation of the "Using a Photoresistor" and "Using a Force Sensitive Resistor" tutorials of Carnegie Mellon University's Designing the Internet of Things class, and "Turn on LED when it's dark - Spark Core" found on Higepon’s blog.