Jonah Brucker-Cohen & Justin Blinder made StockBank as their entry to FutureAdvisor’s “build a better piggy bank” contest. Uses some Adafruit gear including our coin accepter, cool!

StockBank is a networked piggy bank with the end goal of collecting enough money to buy one share of the three technology stocks of Google, Apple, and Facebook. As someone drops a coin into the bank, the display shows the amount of the selected stock share price decreasing until it levels off at zero, which means that there is enough money inside the bank to buy one share. The bank then automatically connects to an online broker, purchases the share, and blinks the pig. When the bank is emptied, the counter resets back to another share price and begins the process over again.

The project exists as an open source, networked object that prompts users to stay connected to the current stock valuation of technology corporations and see how they change and fluctuate over time. It reinvents the classic piggy bank by instead of counting money for saving, it connects in real-time to actual stock prices and gives the user an estimate on the amount of money they need to purchase a share of the specified stock.

Coin Acceptor – Programmable 4 Coin Type – Your project may be free-as-in-speech, but that doesn’t mean it has to be free-as-in-beer. This handy coin validator/acceptor module is just like the ones you’ve seen in arcades. This model has the cool ability to accept up to 4 different coins! For example, you can program it for 4 different US coins, or European, or Japanese OR you can have it accept 4 coins from different countries – say a Chinese Yuan, Japanese Yen, American Quarter and European Euro. First you’ll have to program it with what coins you want it to accept. Any coin from 15mm to 29mm in diameter can be used. Each coin is assigned a number of pulses, so for example, a nickel should be 1 pulse, a dime, 2 pulses, a quarter 5 pulses and a half dollar 10 pulses. When a valid coin is inserted, the output line will pulse for 20-60ms (configurable). The acceptor looks for diameter, thickness, dropping speed, etc to determine if a coin is valid.