Ham Arduino displays show almost everything from simple text to graphics. In this article, we look at the two main types of displays you will use.
Most packaged Arduino projects end up needing a display. These are simple to mount in a metal or plastic project box. You can choose between either an LCD (above right) or color TFT (above left) display. Some TFT displays also come with touch input, just like your smart phone.
At first, you might want to use an LCD display. These come in 2 line by 16 character and 4 line by 20 character versions.
In the past, hooking up an LCD used too many of your digital pins on the Arduino. Look for LCD displays that now contain an I2C interface. With I2C bus you only need two pins to control the display. For these, you need to replace the built in Liquid Crystal library with one that supports I2C. Here is a tutorial explaining how to hook up an I2C display with an ultrasonic range detector.
Ham Arduino Displays – Just Like On Your Radio
Most modern radios have incorporated graphic front panel displays. These use backlit TFT screens, just like your laptop and phone. The main difference between text versus graphics displays is the amount of computing power required to run them. You will use a lot of your Arduino memory and cycles to run graphic screens. Keep that in mind. Programming is also more complicated, especially if you display graphics. This tutorial will explain how to setup a TFT with touchscreen.
The one thing you need to know when hooking up a display is the identity of the chips used to control display and touch. Here is an example of my investigation of the TJCTM24024 module. Armed with that information, you can find and install the right libraries in your Arduino IDE. Also, you need to know how the TFT will communicate with your Arduino. Typically, the SPI bus will run the display, but you often need to connect the touch pad to analog input pins.
TFT displays are more expensive, typically starting around $10 for 2.4 inch models. This is plenty for most projects. One last point: usually the TFT displays run on 3.3V and are not 5V tolerant.