Apple Coin Bank Plants the Seed of Saving

Consider the piggy bank. Behind that innocent, docile expression is a capitalistic metaphor waiting to ruin your fond memories of saving for that BMX bike or whatever else it was that drove home the value of a dollar. As fun as it is to drop a coin in a slot, the act of saving your pennies and learning financial responsibility could be a bit more engaging.

It seems like [gzumwalt] feels the same way. He’s designed a coin bank for his grand-kids that takes a more active role in the deposit process—it straight up eats the things. Put a coin on the platform and the upper half of the apple’s face is pushed open by an arm that pulls the coin inside on its return path.

Continuing with the money-saving theme, [gzumwalt] didn’t use a micro or even a 555. No, the core of this project is a pair of micro lever switches, a small gear motor, and 4.5V DC. When a coin hits the platform, the first switch engages the motor. The motor drives a 3-D printed mechanism modeled after Hoeckens’ linkage, which converts rotational motion to (nearly) straight-line motion. The second switch stops the cycle. Confused? You can sink your teeth into it after the break.

Don’t worry, the kids don’t have to slice up the apple when it’s time to go to the candy store, ’cause there’s a screw-in hatch on the bottom. This is because [gzumwalt] is a wizard of 3-D printing and design. Not convinced? Check out his balloon-powered engine or his runs-on-air plane.

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This piggy bank is our stock broker

piggy-bank-stock-buy

[Johna and Justin] are working to take the emotion out of playing the market. They built this piggy bank which automatically purchases stock when your coinage totals the cost of a single share. That’s right, just turn the selector to one of your three chosen stocks (Google, Facebook, and Apple are used in this example) and plug in some coins. The bank counts your money, compares it to the current online stock price, and pulls the trigger if you have enough dough. You can check out a demo clip after the jump.

The hardware is rather simple thanks to Adafruit’s programmable multi-coin acceptor. It handles the cash and it’s pretty easy to interface with the Arduino which handles the rest of the work. It connects to a computer via USB, depending on a PHP script to poll the current price. We dug through the code repository just a bit but didn’t find the snippet that does the actual stock purchase. Whether or not they actually implemented that, it’s certainly an interesting concept.

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