Official 7" Pi Touchscreen doesnt work

[Pirate 3]

Hi,

The Raspbian official 7" touchscreen doesnt work on the 2S like it did on the TinkerBoard and S

/sys/class/backlight is empty
/sys/devices/platform/ff150000.i2c/i2c-3/3-0045/tinker_mcu_bl doesnt exist like it did on TinkerBoard

[Pirate 3]

root@linaro-alip:/sys/devices/platform# dmesg | grep ili9
[    2.017431] tinker-mcu: tinker_mcu_ili9881c_probe: address = 0x36
[    2.023535] tinker-mcu: tinker_mcu_ili9881c_probe: i2c_id= 0x8
[    2.075209] tinker-mcu: tinker_mcu_ili9881c_probe: init_cmd_check[-6] failed, 0
root@linaro-alip:/sys/devices/platform# dmesg | grep 5406
[    6.117044] tinker-ft5406: tinker_ft5406_probe: address = 0x38
[    6.122899] tinker-ft5406: tinker_ft5406_probe: touch is on DSI-0
[    6.638485] tinker-ft5406: tinker_ft5406_probe: wait connected timeout

 

[Pirate 3]

I know the problem. On Tinkerboard 2, they swapped the place of camera and display cord.

 

Tinkerboard 2 MIPI display port is 22-pin 4 lane, up to 1080p, but RPi's is 15-pin 2 lane. So need a convert cable or RPi's adaptor.
https://uk.rs-online.com/web/p/raspberry-pi/1363742/
or https://www.waveshare.com/cm-dsi-adapter.htm

[Frank3_Wu 2]

Hi @Pirate,

Glad to help you clarify the problem, and let us know if there is any good news after you get the adapter board.

[philc 0]

I connected RPi 7" display to Tinkerboard 2 through Waveshare cm-dsi adapter referenced above.  For both Android 10 and Android 11, I get the Tinkerboard splash screen on the Rpi display but do not get the Android splash screen.  Is there a configuration file I need to update?

[philc 0]

Got it working with Android 11 by adding following line to /dtoverlay/config.txt:

overlay=DP_VOPB

[tooz 53]

hello @philc, 

great to know that the board and the display are up and running, let us know if there's other issues.

[Fra189 0]

Hi,

I tried a dsi cable 15 to 22 pins but display remain blank.

Is there a way to switch CSI to DSI and connect the panel there? In case, will hdmi still be usable?

In config.txt Is mentioned thep anel-asus-DSI1-overlay file but It doesn't exist in userdata.

Many thanks

[tooz 53]

hello @Fra189, 

which os version and panel are you using?

[Fra189 0]

Hi @tooz
Thank you for repliyng.
I'm using official 2.1.6 Debian 10 image.
It came out that it was a cable issue, with a physical (15 to 22 pins) ,adapter the screen now works and I'm able to use rpi 7'' display.
By the way, the panel-asus-DSI1-overlay is not present in overlay folder. I still would like to use the CSI connector without the adapter. Would it be possible to attach rpi screen to the 15 pins CSI connector? What changes do I need to do in dts?
Many thanks.

[tooz 53]

hello @Fra189, 

Quote

By the way, the panel-asus-DSI1-overlay is not present in overlay folder. I still would like to use the CSI connector without the adapter. Would it be possible to attach rpi screen to the 15 pins CSI connector? What changes do I need to do in dts?

the dsi and csi interfaces are different and cannot be configured as such