Guide to installing old lcd display on a RPi Model (A) 2011 running the latest 4.x Raspbian
assume your logged in with root permissions
 |
 |
| Watterott MI0283QT-2 Rev 1.0 lcd display with touch screen |
RPi ShieldBridge Rev 1.1 |
Upgrade to the latest linux kernel version with DT support
apt-get update && apt-get upgrade
Check the modules are available :-
modprobe -c | grep -e spi_bcm -e ads7846 -e fb_hx8347d -e fbtft
...
alias platform:bcm2708_spi spi_bcm2708
alias platform:fb_hx8347d fb_hx8347d
...
alias spi:ads7846 ads7846
alias spi:fb_hx8347d fb_hx8347d
...
alias symbol:fbtft_dbg_hex fbtft
alias symbol:fbtft_framebuffer_alloc fbtft
...
Check the fbtft_device will load the MI0283QT-2 driver :-
modprobe fbtft_device name=list; dmesg
...
[15006.905292] fbtft_device: SPI devices registered:
[15006.905376] fbtft_device: ads7846 spi0.1 2000kHz 8 bits mode=0x00
[15006.905399] fbtft_device: 'fb' Platform devices registered:
[15006.905459] fbtft_device: soc:fb id=-1 pdata? no
[15006.905534] fbtft_device: Supported displays:
[15006.905549] fbtft_device: adafruit18
[15006.905616] fbtft_device: agm1264k-fl
[15006.905626] fbtft_device: dogs102
...
[15006.905727] fbtft_device: itdb24
[15006.905759] fbtft_device: mi0283qt-2
[15006.905769] fbtft_device: mi0283qt-9a
[15006.905780] fbtft_device: mi0283qt-v2
...
Update config.txt to load the required spi and touch screen overlay
nano /boot/config.txt
dtparam=spi=on
dtoverlay=ads7846,cs=1,speed=2000000,penirq=25,swapxy=1,xmin=250,xmax=3780,ymin=160,ymax=3930,pmax=255,xohms=60
Update cmdline to map the default console onto the display
Note: linux kernel command line is limited to 1024 characters.
nano /boot/cmdline
.... elevator=deadline rootwait consoleblank=0 fbcon=map:10
Update modules to load the fbtft_device driver
nano /etc/modules
fbtft_device name=mi0283qt-2 cs=0 gpios=reset:23,led:24 speed=20000000
Modify the RPi ShieldBridge
 |
 |
| Solder bridge JIRQ |
IO7, IO8, IO23, IO24 & IO25 usage |
Troubleshooting
Manually loading the lcd module
modprobe fbtft_device name=mi0283qt-2 cs=0 gpios=reset:23,led:24 speed=20000000 debug=3
lsmod
Module Size Used by
fbtft_device 35066 0
fb_hx8347d 4747 2
fbtft 34291 2 fb_hx8347d,fbtft_device
fb_sys_fops 1573 1 fbtft
syscopyarea 3113 1 fbtft
sysfillrect 3592 1 fbtft
sysimgblt 2286 1 fbtft
ls /dev/fb*
/dev/fb0 /dev/fb1
Testing the lcd module
dd if=/dev/zero bs=512 count=300 | tr "\000" "\377" > /dev/fb1
Set the screen white
dd if=/dev/zero bs=512 count=300 | tr "\000" "\150" > /dev/fb1
Set the screen purple
 |
| dd if=/dev/fb1 of=raw.bmp |
Note : the display is written RGB565 (16bit) per pixel = 153600 bytes (320x240x2)
You can then import/export using the GIMP raw bmp format:-
Manually loading the touch screen
modprobe ads7846 cs=1 speed=2000000 penirq=25 swapxy=1 xmin=250 xmax=3780 ymin=160 ymax=3930 pmax=255 xohms=60
lsmod
Module Size Used by
ads7846 12520 0
hwmon 4420 1 ads7846
ls /dev/input/*
/dev/input/event0 /dev/input/mice /dev/input/mouse0
/dev/input/by-path:
platform-20204000.spi-event
Testing the touch screen
apt-get install evtest
evtest /dev/input/event0
Input driver version is 1.0.1
Input device ID: bus 0x0 vendor 0x0 product 0x0 version 0x0
Input device name: "ADS7846 Touchscreen"
Supported events:
Event type 0 (EV_SYN)
Event type 1 (EV_KEY)
Event code 330 (BTN_TOUCH)
Event type 3 (EV_ABS)
Event code 0 (ABS_X)
Value 0
Min 250
Max 3780
Event code 1 (ABS_Y)
Value 0
Min 1
Max 4095
Event code 24 (ABS_PRESSURE)
Value 0
Min 0
Max 65535
Properties:
Testing ... (interrupt to exit)
Event: time 1439880623.938423, type 1 (EV_KEY), code 330 (BTN_TOUCH), value 1
Event: time 1439880623.938423, type 3 (EV_ABS), code 0 (ABS_X), value 1519
Event: time 1439880623.938423, type 3 (EV_ABS), code 1 (ABS_Y), value 1350
Event: time 1439880623.938423, type 3 (EV_ABS), code 24 (ABS_PRESSURE), value 65158
Event: time 1439880623.938423, -------------- SYN_REPORT ------------
Event: time 1439880623.948523, type 3 (EV_ABS), code 0 (ABS_X), value 1503
Event: time 1439880623.948523, type 3 (EV_ABS), code 1 (ABS_Y), value 1391
Event: time 1439880623.948523, type 3 (EV_ABS), code 24 (ABS_PRESSURE), value 65149
Event: time 1439880623.948523, -------------- SYN_REPORT ------------
Event: time 1439880623.958356, type 3 (EV_ABS), code 0 (ABS_X), value 1455
Event: time 1439880623.958356, type 3 (EV_ABS), code 1 (ABS_Y), value 1472
Event: time 1439880623.958356, type 3 (EV_ABS), code 24 (ABS_PRESSURE), value 65147
...
Calibrating the touch screen
apt-get install libts-bin
export TSLIB_TSDEVICE=/dev/input/event0
export TSLIB_FBDEVICE=/dev/fb1
ts_calibrate
No comments:
Post a Comment