Intro to Arduino Part 2 The Breadboard

Arduino Lesson 2: Using a Breadboard In this lesson we will begin to build circuits on a Breadboard that will be controlled by the Arduino. We will start out with simple circuits and build from there. It is important for you to learn the basics before moving on, and one of the most important basics is how to use a Breadboard. In this lesson we will learn the ins and outs of breadboards, and by the end of the lesson you will have your first circuit built, and it will be controlled by the Arduino.

The Breadboard In order to build a circuit, you have to connect circuit elements together. You could run a bunch of wires to connect components, but you will find that very quickly you end up with a rats nest of wires, and it becomes impossible to debug. In order to keep your circuit organized you need to use a breadboard, pictured below.

The Breadboard The breadboard allows you to connect components together by plugging them into the little holes. The key is to understand how the holes are connected. As you can see in the diagram, the holes in a column (when oriented as shown in the picture) are connected together. So to connect components together you need to plug the leads you want connected into the same column. Note that the columns are not connected across the “trench” in the center of the board.

The Breadboard Also notice that as the long rows ( colored purple) at the top and bottom are connected together. These are typically used to create “rails”.  These are typically used for grounds and supply voltages you might need to connect many components to.

Circuit All the circuits from now on will be built on the breadboard and will use the Arduino to control the circuit. The advantage of using a breadboard is that you can swap the pieces out easily and if you make a mistake you can correct it with out any problem. If you take a look at your Arduino board you will notice that a breadboard is attached to it. There are two sets of letters across the top and numbers that will go down the side. We will plug the different components using these two things. For example you might be instructed to place a resistor in 3A and 5A. So you would just put one end of the resistor is each hole. Remember electricity flows across the rows. If you plug a battery into 1E the electricity will flow through D,C,B,A also. It will not make the jump to F,G,H,I, and J with out the help of another wire.

Lets Build a Circuit We are going to build this circuit in the diagram on the right. This circuit contains 5 things. Part 1 The Arduino board. Part 2 The breadboard. Part 3 Two wires. Part 4 An LED Part 5 A 330 ohms resistors

First Step Add 2 Wires In this step you are going to take 2 wires from your kit (color does not matter). Place one wire from the GND slot on the Arduino to hole 15-A. The other wire will go from pin #13 from the Arduino to hole 20-A.

Second Step Add LED Insert the short leg of the LED (which is the negative side) into hole 15-E and the long leg into hole 16-E

Third Step Add the Resistor Now we need to add the resistor. Find the 330 ohms resistor (the colors will be red, red, brown). One end, (It does not matter what end goes where) goes into hole 16-D and the other end will go into 20-D. You have just completed the circuit now lets load the code.

Load the Code This is the same sketch you wrote from part 1. You should have saved it, but if you didn’t you have to write it again. After you write it you need to upload to the board by clicking on the Arrow button

It should Like This

Credit Call me over so I can see that you have successfully completed the circuit.

How Did This Happen Lets go through the circuit and see how this happens. It is just like in the first sketch you wrote that made the LED blink. Last time we connected the LED to pin #13 and GND (which stands for ground if you forgot). This time we used the breadboard. It was the same program which sends the power to pin #13 but this time a wire carried the voltage to row 20. It then went through the resistor (which protects the LED from to much voltage) it goes up one side of the LED and then back to the GND through a wire to the Arduino. This completes the circuit, remember the voltage always must go back to were it starts.

Review Leave the circuit the way it is for the part 3 Save your program, we will use part of it again in part 3 The breadboard allows you to make and change a circuit very easily. The electricity flows across the rows but not down the columns. It also does not flow over the gap between E and F a wire must take it to the other side. A resistor will have three colored stripes on it to identify the amount of resistance. More on that next lesson. You can use the Arduino to control what is going on in the Breadboard. There is no quiz for this section.