LCD_HD44780_driver

Discripton

Driver for Raspbery PI 3/4 to dispaly string on LCD screen with controller HD44780. It implemented such as file in /proc. This code will work with Linux kernel version > 6.1.

Find out the version number:

uname -a

If you start on PI 4:

gpio_registers = (int*)ioremap(BCM2711_GPIO_ADDRESS, PAGE_SIZE);

If you start on PI 3:

gpio_registers = (int*)ioremap(BCM2837_GPIO_ADDRESS, PAGE_SIZE);

How work with it

If you want use it, run:

sudo insmod HD44780_driver.ko

Then, if you want to show string in display, run:

echo "Hello 5" > /proc/HD44780_driver

if you want to customize it:

sudo apt install raspberrypi-kernel-headers

When you finished change code, compile it with:

make

To unset driver from kernel:

sudo rmmod HD44780_driver

To set driver in kernel:

sudo insmod HD44780_driver.ko

To show messages from driver:

dmesg

Connection of display: