4x4 Buzzers by ssoderholm

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Lockout buzzer and timing system for Science Bowl This is a buzzer system optimized for practice for National Science Bowl competition. It includes buttons and indicator lights for two teams of up to 6, to accommodate the additional students we have at practice (a competition team is only 4). The LED's, shown as separate from buttons will actually be built in to the buttons. But, since the LED and button are electrically separate, this setup works for virtual prototyping. It includes a "clear" button as well as 5 and 20 second timers for toss-up and bonus questions, respectively. I'm using a piezo buzzer for audio feedback. I considered a round timer, but a stopwatch that can be paused more easily is probably better. Pin 13 is still open, so it could be a pause button in the future? I am prototyping this circuit to use with an Adafruit Pro Trinket (5V), which is why I am not utilizing pins 2 or 7. The plan is to power this circuit with a 9V battery or LiPo pack on a series switch so it won't require being plugged in during use. <span style="display:block; text-align:center;"><iframe width="450" height="380" src="https://123d.circuits.io/circuits/1296321-buzzers/embed" frameborder="0" marginwidth="0" marginheight="0" scrolling="no"></iframe></span> Key components: Adafruit Pro Trinket: www.adafruit.com/products/2000 LED momentary pushbutton: www.adafruit.com/products/1439