BeagleBone Black LCDs with Prebuilt FBTFT drivers

Use small TFT LCDs displays as Linux framebuffer on BeagleBone Black using pre-built fbtft drivers for Linux 3.8.13-bone50

BeagleBone Black LCDs with Prebuilt FBTFT drivers

Posted by Angel on 2015-11-19T05:22:55-05:00

Categories: BeagleBone Black

 

Step 1: Download, Flash & Boot Image

 Download bone-debian-7.5-2014-05-14-2gb image:

 

http://debian.beagleboard.org/images/bone-debian-7.5-2014-05-14-2gb.img.xz

 

Write image to SD card.  Here is example on my Linux laptop:

$ sudo dd if=/home/afustini/Downloads/bone-debian-7.5-2014-05-14-2gb.img of=/dev/sdc

Boot the BeagleBone with the microSD card and verify it is running Linux kernel 3.8.13-bone50:

$ cat /proc/version

Linux version 3.8.13-bone50 (root@imx6q-wandboard-2gb-0) (gcc version 4.6.3 (Debian 4.6.3-14) ) #1 SMP Tue May 13 13:24:52 UTC 2014

 

$ cat /etc/dogtag

BeagleBoard.org BeagleBone Debian Image 2014-05-14

 Step 2: Expand SD card to ensure full capacity

 Run script to grow the filesystem as root on BeagleBone:

$ sudo /opt/scripts/tools/grow_partition.sh

 

sfdisk: backing up partition layout.

sfdisk: initial calculation.

 

Disk /dev/mmcblk0: 242560 cylinders, 4 heads, 16 sectors/track

Old situation:

Units = mebibytes of 1048576 bytes, blocks of 1024 bytes, counting from 0

 

 

Re-reading the partition table …

BLKRRPART: Device or resource busy

The command to re-read the partition table failed.

Run partprobe(8), kpartx(8) or reboot your system now,

before using mkfs

If you created or changed a DOS partition, /dev/foo7, say, then use dd(1)

to zero the first 512 bytes: dd if=/dev/zero of=/dev/foo7 bs=512 count=1

(See fdisk(8).)

 Reboot the BeagleBone and verify that the root filesystem now is using the entire capacity of the the microSD card:

$ df -h

Filesystem Size Used Avail Use% Mounted on

rootfs 7.2G 1.6G 5.4G 22% /

 Step 3: Install prebuilt fbtft drivers

Download the prebuilt fbtft kernel modules:

$ wget tronnes.org/downloads/fbtft-2014-02-07-3.8.13-bone50.tar.gz

Install the kernel modules:

$ sudo tar -zxPvf fbtft-2014-02-07-3.8.13-bone50.tar.gz

/lib/modules/3.8.13-bone50/extra/

/lib/modules/3.8.13-bone50/extra/fb_pcd8544.ko
/lib/modules/3.8.13-bone50/extra/fb_ili9340.ko


/lib/modules/3.8.13-bone50/extra/fbtft.ko

 

$ sudo depmod

Verify the modules are for 3.8.13-bone50:

$ modinfo fbtft

 

filename: /lib/modules/3.8.13-bone50/extra/fbtft.ko

license: GPL

srcversion: 3C6839F44999EEA4C1D8A9F

depends:

vermagic: 3.8.13-bone50 SMP mod_unload modversions ARMv7 thumb2 p2v8

parm: debug:override device debug level (ulong)

parm: dma:Use DMA buffer (bool)

 Edit /boot/uboot/uEnv.txt to disable HDMI & eMMC “virtual capes” and enable SPIDEV1 “virtual cape”:

$ sudo vi /boot/uboot/uEnv.txt

 Uncomment this cape_disable line for HDMI & eMMC:

##BeagleBone Black:

##Disable HDMI/eMMC

cape_disable=capemgr.disable_partno=BB-BONELT-HDMI,BB-BONELT-HDMIN,BB-BONE-EMMC-2G

 Add this line to enable SPIDEV1:

cape_enable=capemgr.enable_partno=BB-SPIDEV1

 Save the changes uEnv.txt & reboot the BeagleBone

 

Step 4: Load fbtft driver

 Verify which capes are loaded:

$ cat /sys/devices/bone_capemgr.9/slots

 

0: 54:PF—

1: 55:PF—

2: 56:PF—

3: 57:PF—

4: ff:P-O– Bone-LT-eMMC-2G,00A0,Texas Instrument,BB-BONE-EMMC-2G

5: ff:P-O– Bone-Black-HDMI,00A0,Texas Instrument,BB-BONELT-HDMI

6: ff:P-O– Bone-Black-HDMIN,00A0,Texas Instrument,BB-BONELT-HDMIN

7: ff:P-O-L Override Board Name,00A0,Override Manuf,BB-SPIDEV1

Use fbtft_device kernel module to load the fb_st7735r driver for Adafruit 1.8″ TFT LCD display connected to SPI1:

$ sudo modprobe fbtft_device busnum=1 name=adafruit18 debug=7 verbose=3 gpios=dc:48,reset:60

OR

 Use fbtft_device kernel module to load the fb_ili9340 driver for Adafruit 2.2″ TFT LCD display connected to SPI1:

$ sudo modprobe fbtft_device busnum=1 name=adafruit22a debug=7 verbose=3 gpios=dc:48,reset:60

NOTE: a suffix is important in adafruit22a

 

/dev/fb0 device should now exist:

$ ls -lsda /dev/fb*

0 crw-rw—T 1 root video 29, 0 Oct 30 06:27 /dev/fb0

 The system console should now be displayed on the LCD:

IMG_20151030_005012.jpg

More photos of fbtft working for 1.8″ & 2.2″ TFT LCDs

 

Example kernel log:

[ 181.848604] fbtft_device: SPI devices registered:

[ 181.848671] fbtft_device: spidev spi1.1 16000kHz 8 bits mode=0x00

[ 181.848705] fbtft_device: spidev spi1.0 16000kHz 8 bits mode=0x01

[ 181.848728] fbtft_device: ‘fb’ Platform devices registered:

[ 181.848860] fbtft_device: omapfb id=-1 pdata? yes

[ 181.849152] fbtft_device: Deleting spi1.0

[ 181.851923] fbtft_device: GPIOS used by ‘adafruit22a’:

[ 181.851960] fbtft_device: ‘dc’ = GPIO48

[ 181.851982] fbtft_device: ‘reset’ = GPIO60

[ 181.852002] fbtft_device: SPI devices registered:

[ 181.852033] fbtft_device: spidev spi1.1 16000kHz 8 bits mode=0x00

[ 181.852061] fbtft_device: fb_ili9340 spi1.0 32000kHz 8 bits mode=0x00

[ 182.235255] Console: switching to colour frame buffer device 60×53

[ 182.236682] graphics fb0: fb_ili9340 frame buffer, 240×320, 150 KiB video memory, 4 KiB DMA buffer memory, fps=20, spi1.0 at 32 MHz

Step 5: Display images and video

 Based on FBTFT Wiki article: Framebuffer use

 

When using a fresh Debian image, one should first update the list of available packages before attempting to install new packages:

$ sudo apt-get update

Reading package lists… Done

W: There is no public key available for the following key IDs:

9D6D8F6BC857C906

 

Fix public key ID warning:

$ sudo apt-get install debian-keyring debian-archive-keyring

 

$ sudo apt-get update

 

Install fbi utility to display image files on the framebuffer device:

$ sudo apt-get install fbi

 

$ wget https://kernel.org/theme/images/logos/tux.png

 

$ sudo fbi -d /dev/fb0 -T 1 -a tux.png

using “DejaVu Sans Mono-16”, pixelsize=16.67 file=/usr/share/fonts/truetype/ttf-dejavu/DejaVuSansMono.ttf

 Tux the Linux mascot should now be displayed on the LCD:

IMG_20151030_024223.jpg

More photos of fbtft working for 1.8″ & 2.2″ TFT LCDs

 

Next, install mplayer to play a MPEG-2 video clip:

$ sudo apt-get install mplayer

 

$ wget http://hubblesource.stsci.edu/sources/video/clips/details/images/hst_1.mpg

 

$ sudo mplayer -nolirc -vo fbdev:/dev/fb0 scale=WIDTH:128 hst_1.mpg

MPlayer svn r34540 (Debian), built with gcc-4.6 (C) 2000-2012 MPlayer Team

 

framebuffer too small for double-buffering, disabling

V: 19.0 570/570 20% 65% 0.0% 0 0

Exiting… (End of file)

 You should now see the video clip playing on the display:

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