This business card duals as a binary clock. Pressing the top button allows the user to scroll through hours, minutes (tens), minutes (ones), and off in binary format displayed on the LEDs. The second button allows the user to set the time. The microcontroller keeps track of the time by using I2C to communicate with the low power RTC module it is also responsible for displaying the time on the LEDs and reading button input. The microcontroller goes into a low power sleep mode when the business card is “off”. The button is linked to a hardware interrupt on the microcontroller that takes it out of sleep when the button is pressed.