Finance Tracker


2012-03-13_123814 LCD_buttons2 OLED-160_2

In an effort to keep track of our finances and stay on budget, I came up with an idea for a finance tracking device.  The device is slightly bigger than a credit card, can live inside my wallet, always ready for you to enter your transaction when you pay for something.  It is optimized for simplicity and a great deal of attention went into making it quick to use, requiring minimum button presses.  The screen is a 320×240 pixel resistive touch screen from 4D systems.  The display was to be combined with a real time clock, voltage boost converter and single lithium cell.  A photo resistor would wake the system up when the wallet was opened, ready for input.  When it got dark, the system would go to sleep.  All transactions would be stored on an uSD card for downloading to a computer.  Eventually, I wanted to have the system downlink the transactions whenever it was in range of a zigbee serial wireless modem connected to the home computer.  I got the screen working with buttons and transactions recording to the uSD card, but started running into limitations with the language.  It had very limited set of variable types, only 16 bits, which wasn’t large enough for large transactions.  I had mostly finished using multiple variables to create a larger one, sufficient for large transactions, when I threw in the towel, and decided dealing with these limitations was more pain than it was worth.


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