### Quick Draw!

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# How does Quick Draw! work?

Quick Draw! Soldering Instructions

## What Makes Quick Draw! Work?

Before we discuss what makes the Quick Draw game work, let’s go over a few definitions.

System: a set of things working together to achieve a common goal. In computers and electronics, a system is a group of related hardware units or programs dedicated to a single application.

The boat pictured below is a complete system.

Subsystem: a self-contained system within a larger system. Subsystems are able to function independently of the larger system they are a part of, but the system would not function properly without any one of its subsystems. In the example pictured above, the motor, radio, and hull are subsystems of the boat. If we were to remove the motor, radio or hull from the boat, they would still be able to perform their individual function; however, the boat would cease to function properly.

Logic Levels: a special signal that digital electronics use to communicate. A 0 or 1 is communicated based on whether the signal line is “off” or “on.” Normally represented as: 0 or 1; LOW or HIGH.

Digital Logic: a set of rules that allows a system to make complex decisions based on high/low signals. Also called Boolean Logic, this is a fundamental concept of electronics and computing. For Quick Draw, digital logic will check to see if a signal is high or low, and then perform a function based on that signal.

Integrated Circuit (IC): also known as “chips” or “microchips,” these amazing little black boxes contain millions of microscopic components that create complete systems which accomplish all sorts of amazing tasks, mostly (but not always) using digital logic.

Each individual IC usually performs only one simple task. For example, a Counter IC can count to ten, a Timer IC will keep track of time, an Adder IC adds two numbers together, and so on and so forth.

Clock: keeps system time and keeps operations synchronized. This is accomplished when the clock sends out high and low signals at set intervals. A single full duration of alternating high and low signals (from the peak of one signal to the other) is called a clock pulse. The amount of times a clock switches between a high and low signal per second is called the clock speed, and is measured in Hertz (Hz).

So, how does Quick Draw work?

Quick Draw boils down to two main parts: the clock and the counter IC. As mentioned in the definition, the counter IC is a simple IC that counts from one to ten using its ten signal output legs. The clock outputs a clock pulse to the counter IC, and when the counter IC senses the logic levels go from low to high, it “counts” to the next leg, which then lights up the next LED in succession.

So, for example, after 2 clock pulses, leg 2 outputs a high signal, lighting up LED 2; and after 7 clock pulses, leg 7 outputs a high signal, lighting up LED 7. Each time a new LED is lit, the previous one is turned off, so that only one LED appears lit at a time.

As the clock continually sends signals, the Counter IC just counts to ten over and over, which lights up each LED in succession until the Stop button is hit.

Once the Stop button is hit, there are two possible outcomes: either we missed the middle LED and lost the round, or we hit it and won, getting a point added to our score! The point increment system uses digital logic, which checks the stop clock signal and a signal from the counter IC. IF we push the “stop clock” button, AND the green winner LED is on, then we get a point!