Recently I decided to level up at electronics engineering. When I went to the 2014 San Mateo Maker’s Fair I picked up an Arduino UNO, not really knowing what to expect. After doing some of the basic tutorials I decided to aim higher and get an LCD screen to play with for my first original project. Though I have many ideas for the LCD screen, I wanted to make sure I knew how to use it properly first. I made a basic text editor with some spare parts, the Arduino Uno and the SparkFun LCD screen.

The way it works is pretty simple: the LCD requires power, ground, and one data pin on the Arduino for serial transmission. The screen is entirely controlled through serial commands, which makes it extremely convenient to work with, and it doesn’t take up many pins (only one!)

I had an Arcade Joy Stick that I hooked up to four of the digital-inputs on the Arduino. This allows the user to move a cursor around. I also had a panel mount potentiometer with a fancy knob. Though it’s easier to type with a keyboard I didn’t have any feasible way to hook one up, so instead I used the potentiometer to dial-in characters. It’s pretty straight foward. Arduino reads analog inputs as a value between 0 and 1024. I divide this value by 8 to get a range of 0-128. I mathematically rounded the division result down, to make the reading more stable. The knob is basically used to select an ASCII character between 0-and-128 and the joystick is used to move the character around the display.

I also added a momentary push button to one of the digital inputs. When this button is pushed, the selected ASCII character is written to the screen and the cursor advances to the right. Using these simple inputs, text can be written out and edited by the user. See the video below for a demonstration!

Feel free to download the source for this project!
http://gmiller.net/assets/Arduino_Text_Editor.ino

July 23, 2014 at 10:11 pm | Other Projects, Video