The security flaws on this common hotel keycard lock are nothing short of face-palmingly stupid. Look closely at the picture above. This is a hotel room door swinging open. The device he holds in h… ...

FSRs are basically a resistor that changes its resistive value (in ohms Ω) depending on how much it is pressed. These sensors are fairly low cost, and easy to use. They also vary some from sensor to ...

Then the point between the fixed pull down resistor and the variable FSR resistor is connected to the analog input of a microcontroller such as an Arduino The way this works is that as the resistance ...