FNLD

FNLD is Nokia 5110 LCD driver for FreeBSD OS. Nokia 5110 LCD is low-cost, low power, and stable GLCD. At the moment many libraries are developed based on C, C++, and Python. These libraries are suitable and use with Arduino and Linux-based OS like Raspbian. If your FreeBSD boots on Raspberry Pi 2, FNLD helps you for sending and showing strings on Nokia 5110 LCD. In the following, First I'll present you how to connect Nokia 5110 LCD to your Raspberry Pi 2 and next illusterate how to prepare FreeBSD and use of this driver.

1-Hardware Connections

You can connect Nokia 5110 LCD to Raspberry Pi 2 SPI bus and use one of its chip select pins: CE0 or CE1. As shown in the below figure, I use CE0. This connection required when we upgrade FDT.

        +----------------------+                                            +-----------+
	|                      |36: GPIO.16                           1: RST|           |
	|                      +--------------------------------------------+           |
	|                      |24: GPIO.6 (SPI.CE0)                  2: CE |           |
	|                      +--------------------------------------------+           |
	|                      |37: GPIO.20                           3: DC |           |
	|                      +--------------------------------------------+           |
	|                      |19: GPIO.10 (SPI.MOSI)                4: DIN|           |
	|                      +--------------------------------------------+   Nokia   |
	|    Raspberry Pi 2    |23: GPIO.11 (SPI.SCLK)                5: CLK|  LCD 5150 |
	|                      +--------------------------------------------+           |
	|                      |2:  5V                                6: VCC|           |
	|                      +--------------------------------------------+           |
	|                      |40: GPIO.21                           7: BL |           |
	|                      +--------------------------------------------+           |
	|                      |39: GND                               8: GND|           |
	|                      +--------------------------------------------+           |
	|                      |                                            +-----------+
	+----------------------+

2-Upgrade FDT

Open /usr/src/sys/boot/fdt/dts/arm/rpi2.dts in your favorite editor (I use ee):

%ee /usr/src/sys/boot/fdt/dts/arm/rpi2.dts

And add on axi section after gpio definitions following codes:

spi0 {
	nl5110 {
		compatible = "nokia,lcd5110";
		spi-chipselect = <0>;
	};
};

Now we must build DTB file. DTB is the binary presentation of FDT and OS understand it. For this change your current directory and go to /usr/src/sys/tools/fdt/:

%cd /usr/src/sys/tools/fdt/

Create an environment variable for declaring machine architecture:

%setenv MACHINE arm

And run make_dtb.sh script, like bellow:

%./make_dtb.sh /usr/src/sys /usr/src/sys/boot/fdt/dts/arm/rpi2.dts .

New DTB file created at the current location and you must move it to /boot/msdos/ in your MMC:

%cp rpi2.dtb /boot/msdos/

And finally reboot the OS:

%reboot

3-Download and Compile

Use git command for downloading FNLD:

%git clone https://github.com/mohsenmoqadam/FNLD

Then go to FNLD directory:

%cd FNLD

And compile it:

%make	

4-Load and use

For load FNLD’s KLD we use kldload command:

%kldload lcd5110.ko

You can use echo command for sending a string to Nokia 5110 LCD:

%echo "Hello World!" > /dev/lcd5110

5-Notes

If you don't have FreeBSD source tree, first download and insert it at /usr/src. for this you can use svn command like this:

%svn co svn://svn.freebsd.org/base/stable/11 /usr/src