HD44780 LCD Display Modules
These modules use the Hitachi HD44780 chip and come in a variety of sizes and colours. The 16 character by 2 line (1602) and 20 character by 2 line (2002) versions are the most common. One line and 4 line varieties are also available.
1. Things to Note.
- Most commonly these work from 5v, but 3.3v versions are also available.
- The yellow/green coloured modules can be viewed with the backlight turned off. The blue modules cannot.
- Some modules have a current limiting resistor in line with the backlight LED but some do not. It is best to test using a 3.3k or so resistor.
- The contrast can be adjusted by connecting the wiper of a 10k trimpot to the contrast adjust pin with the other terminals connected to Vcc and ground.
- In byte programming mode, 10 lines are required from the driving device. In nibble mode, 6 lines are required.
3. Programming and Interfacing