Never Forget Your USB Stick Again

USB sticks¬†are very handy. They are a very portable and relatively inexpensive means of storing data. Possibly the most annoying part about using one of these devices is when you inevitable leave it behind somewhere by accident. This is especially true if it contains sensitive information. [Eurekaguy] feels your pain, and he’s developed a solution to the problem.

[Eurekaguy] designed a custom cap for USB sticks that beeps approximately every minute after the USB stick has been plugged in for five minutes. The cap is 3D printed and then slightly modified with four 1mm holes. Two wires are routed between these holes to make contact points for the VCC and GND pins of the USB stick.

The beep circuit is comprised of a tiny PIC12F629 microcontroller along with a couple of other supporting components. The circuit is wired together dead bug style to conserve space. Three AG5 batteries power the circuit. A small piezo speaker provides the repeating beep to remind you to grab your USB stick before you walk away from the computer.

[Thanks Irish]

A PIC powered pair of electronic dice

[Timothy] is honing his microcontroller skills with this electronic dice project. In addition to giving him an opportunity to work on some code, the use of an 8-pin chip provides a design challenge for driving the twelve pips and providing a user input.

The project started off with some $4 strings of LED Christmas lights. He promptly disassembled the strands, each yielding 100 LEDs. The microcontroller he chose to work with is a PIC 12F629. It’s DIP8 package provides six I/O pins to work with. When examined closely you will find that the pips on a die are always present in pairs with the exception of the center pip. This means that only four pins are needed to drive one die. You can see a pair of transistors above; one is a PNP, the other an NPN. These are both driven from the same uC line, which toggles between the pair of die. This accounts for 5 of the available pins, with the sixth monitoring the push button.