Linux-Device-Driver-for-Character-LCD-Kernel-Level

RaspberryPi version

Tested on Raspberry Pi OS 5.15 (bullseye) (5.15.32-v8+) on a Raspberry Pi 4 Model B. Display used: Electronic Assembly W162-N3LW.

To get this running do:

$ sudo apt-get update
$ sudo apt-get full-upgrade
$ sudo apt-get install git
$ sudo apt-get install raspberrypi-kernel-headers
$ mkdir klcd
$ cd klcd
$ git clone https://github.com/pischky/Linux-Device-Driver-for-Character-LCD-Kernel-Level.git
$ cd Linux-Device-Driver-for-Character-LCD-Kernel-Level/code/klcd_final/
$ make
$ sudo make install

Note: If any of the apt-getabove updates the linux kernel you should do a reboot before proceeding.

The driver should now load on every boot. Boot now and test:

$ echo "Hello" >/dev/klcd

Note: There are more targets in the Makefile. Read it!

Original Text

a kernel level Linux Device Driver for a 16x2 character LCD (with HD44780 LCD controller) with 4 bit mode.

A demo video is available here: https://www.youtube.com/watch?v=icP9ckrTLKc

This is a kernel level Linux Device driver to control a 16x2 character LCD (with HD44780 LCD controller) with 4 bit mode. The LCD is interfaced with a micro-controller using GPIO pins. The program has been tested on Linux 3.8.13 debian, and the target board is Beaglebone Black ARM micro-controller.

This project is a continuation of my user level program, which was not originally developed with Linux in mind. The project has been developed in a form of loadable kernel module, cross-compiled in a Desktop PC.

• The datasheet was found from here: https://www.sparkfun.com/datasheets/LCD/HD44780.pdf

• And the LCD was purchased from here: http://www.amazon.com/gp/product/B004MGXOUQ/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1

    				Reference
  

  [1] HD44780U (LCD-II), Hitachi Ltd., Tokyo, Japan, 1998.