LCD modules are very commonly used in most embedded projects, the reason being its cheap price, availability, and programmer-friendly. Most of us would have come across these displays in our day to day life, either at PCO’s or calculators. Alphanumeric Graphical LCD (2004A) is a 20x4 Blue/Green Coloured Liquid Crystal Display. It can display 4 lines of text and each line can have up to 20 characters in it, which is bigger than the but the programming is almost same. These characters can either be text, numbers, graphical symbols or even custom characters. It can be used in DIY projects, to display the data on IoT projects, etc.

Specifications:

• Wide viewing angle and high contrast 
• Industry-standard HD44780 equivalent LCD controller built-in 
• 5V DC LED blue backlight 
• Don't need a separate power supply for the backlight 
• Supported 4 or 8-bit parallel interface 
• Display 4-line x 20-character 
• Operate with 5V DC 
• Operating Temperature -20°C to 70°C
• Dot Matrix 5×8 Dots

Product Description

We know that each character has 40 Pixels and for 80 Characters we will have 3200 Pixels. Further, the LCD should also be instructed about the Position of the Pixels. It is a hectic task for the microcontroller, hence Driver IC like ST7066 is used, which is mounted on the backside of the LCD Module.it takes data from the Microcontroller and processes them to display on the LCD Screen. You can use it in 8 bit parallel interface or 4 bit parallel interface mode if you need to connect fewer lines to the microcontroller.

Comparison between 16*2 LCD and 20*4 LCD

There are not many differences between the two LCD screens apart from the obvious one that 16*2 can display only 32 characters and 20*4 can display 80 characters. So you have to choose the display according to your needs. If you need a display to show a lot of data then go for 20*4 size and if there is not too much of data to display then go for 16*2 LCD. It also depends on the packaging size of your project. If space is at a premium then go for smaller sized 16*2 else its 20*4.

Additional Resources