Arduino and LCD Screens

For this project, you will need 1 SparkFun Redboard Inventor's kit, which includes all necessary components.

If this kit is unavailable, you can buy all of the materials separately as listed above.

Although jumper wire colors are not important in making simple circuits, it is good practice for major projects to follow color codes: red for positive, black for negative, and other colors to denote where data is flowing to and from. If you would like to follow the color conventions, the number of each colored wire goes as follows: 5 black wires, 4 red wires, 2 green wires, 2 blue wires, 2 orange wires, and 1 yellow wire.

Go to https://www.arduino.cc/en/Main/Software and install the Arduino IDE software for use on your computer. If you do not have an Arduino or the Arduino IDE does not work on your device, you can follow along digitally by creating an Arduino circuit at https://www.tinkercad.com/circuits.

Once the IDE is installed, you will need to connect your Arduino to your computer. To do this, plug one end of the USB cable to the Arduino Uno and then the other end of the USB to your computer’s USB port.

Once the board is plugged in, you will need to open the IDE and click on Tools > Board > Arduino Uno to select the board.

Next, you have to tell the Arduino which port you are using on your computer. To select the port, go to Tools > Port and then select the port that says Arduino.

Plug one red wire into the 5V port on the Arduino board and the positive terminal (+) on the breadboard. Plug one black wire into the ground (GND) port on the Arduino board and the negative terminal (-) on the breadboard.

Connect the LCD with its bottom port (GND) plugging into J30 and its top port (LED) plugging into J15. Connect one red wire from the positive terminal (+) to f29 and one black wire from the negative terminal (-) to f30.

Connect the potentiometer with its right leg in A6, middle leg in A7, and left leg in A8. Connect one red wire from the positive terminal (+) to E6, one blue wire from E7 to F28, and one black wire from the negative terminal (-) to E8.

Connect a green wire from F27 to port 12 on the Arduino board, a black wire from F26 to the negative terminal (-), and an orange wire from F25 to port 11 on the Arduino board.

Connect a yellow wire from port 5 on the Arduino board to F20, an orange wire from port 4 on the Arduino board to F19, a blue wire from port 3 on the Arduino board to F18, and a green wire from port 2 on the Arduino board to F17.

Connect a 330Ω Resistor with one leg on the positive terminal (+) and one leg in A14. Connect a red wire from B14 to F16, and a black wire from the negative terminal (-) to F15.

The resistor here keeps the current to the backlight limited. Without this resistor, the backlight may become overpowered and explode.

Download the sample code here: https://tinyurl.com/rkgaajo

Click the checkmark icon to compile your sketch, and the right arrow icon to upload to your Arduino board. As soon as you upload the code, the LCD will turn on!

If the LCD does not light up or has become too bright, turn the potentiometer until the text appears. This knob acts as a backlight dimmer.

While this code simply prints "hello, world!" on the top line and a seconds-counter on the bottom line, you can change the text that appears by doing some simple programming. Open up the Arduino IDE and find where the code calls lcd.print("hello, world!"); within the void setup() function and change "hello, world" to anything you'd like! There is a character limit of 16 characters per line, so beware of cut off words.

If you would like to add text to the bottom row, or mess around with the counter itself, find the lcd.print call within the void loop() function. Change millis() / 1000; (the counter that counts in milliseconds then divides by 1000 to find seconds) to either a new text call (remember to use quotation marks!) or tinker around with the numbers within the counter.