kedei 3.5 inch spi tft lcd version 3 in stock
While googling for any info about lcd controller I came across this page: http://heikki.virekunnas.fi/2015/raspberry-pi-tft/, author managed to get from manufacturer patch file for kernel sources and tested it with 4.1.y - on which lcd worked. But still LCD replace HDMI, but I want to use this screen as additional for user interaction, while the bigger on HDMI as presentation monitor.
I have looked through files that he (author of page `heikki.virekunnas.fi`) published, and I came to conclusion that the patch do not changes standard ILI9341 driver but only replace default framebuffer and directs it to ili driver while cutting out hdmi, only single mention in patch file about ili9341 is adding it"s .ko file to $obj in makefile... wow I"m so smart
Since, fbtft has been merged with rpi kernel, so the fb drivers (including ili9341.c) was moved to fbtft_device driver (so the author of page can"t compile latest kernel with driver+patch).
So something about hardware, which I reverse engineered by the "hard way" - "grab multimeter and run through all LCD FPC pins and shift register pins"
Now I noticed there is "9486L" which can suggest that LCD screen is controlled by ILI9486L, I found this LCD on taobao too but I can"t contact seller.
I"m pretty sure about D/C (Pin 37 on LCD) and Reset (Pin 19 on LCD) pins by looking into driver code, but I can"t identify other signals (WR/RD/CS/etc...)
[ 0.000000] Linux version 3.18.9-v7 (lgh@lgh-ThinkPad-X200) (gcc version 4.7.1 20120402 (prerelease) (crosstool-NG 1.15.2) ) #7 SMP PREEMPT Sun Jun 28 09:33:18 CST 2015
[ 0.000000] Kernel command line: dma.dmachans=0x7f35 bcm2708_fb.fbwidth=656 bcm2708_fb.fbheight=416 bcm2709.boardrev=0xa01041 bcm2709.serial=0x2938b030 smsc95xx.macaddr=B8:27:EB:38:B0:30 bcm2708_fb.fbswap=1 bcm2709.disk_led_gpio=47 bcm2709.disk_led_active_low=0 sdhci-bcm2708.emmc_clock_freq=250000000 vc_mem.mem_base=0x3dc00000 vc_mem.mem_size=0x3f000000 dwc_otg.lpm_enable=0 console=ttyAMA0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait
[ 4.838806] input: MOSART Semi. Rapoo 2.4G Wireless Touch Desktop as /devices/platform/bcm2708_usb/usb1/1-1/1-1.3/1-1.3:1.0/0003:24AE:1000.0001/input/input1
[ 4.862704] hid-generic 0003:24AE:1000.0001: input,hidraw0: USB HID v1.10 Keyboard [MOSART Semi. Rapoo 2.4G Wireless Touch Desktop ] on usb-bcm2708_usb-1.3/input0
[ 4.902783] input: MOSART Semi. Rapoo 2.4G Wireless Touch Desktop as /devices/platform/bcm2708_usb/usb1/1-1/1-1.3/1-1.3:1.1/0003:24AE:1000.0002/input/input2
[ 4.926400] hid-generic 0003:24AE:1000.0002: input,hiddev0,hidraw1: USB HID v1.10 Mouse [MOSART Semi. Rapoo 2.4G Wireless Touch Desktop ] on usb-bcm2708_usb-1.3/input1
- Controller is not ILI9341/ILI9325 - those are for smaller displays (320x240, etc...), I guess this might be ILI9486/9488 because they are for 480x320 displays. But when I compared init with DS it does not fit right so LCD can have a clone of ILI9486/9488 ...
- Module use only SPI interface and two CE signals (CE0 for touch controller, CE1 for LCD shift registers - compared to others lcd modules, in KeDei module this is swapped),
I had in plans to create a custom driver but I decided this is not worth my time. I"m going to "re-interface" this lcd to be supported by fbtft. I have a prototype pcb with fbtft-spi interface ready (I have to send this project to pcb prototype service).
Unfortunatly, because of my "spider-circuit" I"ve broken my lcd (I"ve made a some short