7'' waveshare lcd hat

[tokanawa]

Hi, I'm trying to connect this screen to stereopi with compute module 3, but all a got so far is black screen with backlit on.
Like this:

stereopi.jpg (108.69 KiB) Viewed 194 times

Running on raspbian buster. I2C and SPI enabled and here's my config:

Code: Select all

[all]
dtoverlay=vc4-fkms-v3d
start_x=1
gpu_mem=128
dtoverlay=dpi24
enable_dpi_lcd=1
display_default_lcd=1
dpi_group=2
dpi_mode=87
dpi_output_format=0x6f005
hdmi_cvt 1024 600 60 6 0 0 0

I also tried to follow this tutorial, but nothing really changed.
Any suggestion on what I am doing wrong?

[Realizator]

Hi Tokanawa,
I’ve looked into Waveshare Wiki for this screen.
The first thing I noticed in your config is that you’re trying to load both dpi24 and vc4-fkms-v3d overlays. It is not good idea, as they may give you hardware conflicts.

Second mention is that dpi24 overlay try to rearrange pins, and angry for resources: https://www.raspberrypi.org/documentati ... /README.md
It may affect on stereoscopic cameras support and conflict with our dt-blob.bin, so it is better to do some delicate pin arrangement analysis.

Also I’d like to ask, did you try to run this screen with a classic Raspberry Pi (ideally 3B or 3B+, as they have the same CPU as Compute Module 3/3+)?

[tokanawa]

Hi again.
On 3B+ the screen works perfectly.
I've disabled vc4-fkms-v3d, but nothing really changed.
About pin rearrangement, here is gpio output on both raspberries:

gpio on 3B+

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BANK0 (GPIO 0 to 27):
GPIO 0: level=1 fsel=6 alt=2 func=PCLK
GPIO 1: level=1 fsel=6 alt=2 func=DE
GPIO 2: level=0 fsel=6 alt=2 func=LCD_VSYNC
GPIO 3: level=1 fsel=6 alt=2 func=LCD_HSYNC
GPIO 4: level=0 fsel=6 alt=2 func=DPI_D0
GPIO 5: level=0 fsel=6 alt=2 func=DPI_D1
GPIO 6: level=0 fsel=6 alt=2 func=DPI_D2
GPIO 7: level=1 fsel=6 alt=2 func=DPI_D3
GPIO 8: level=0 fsel=6 alt=2 func=DPI_D4
GPIO 9: level=0 fsel=6 alt=2 func=DPI_D5
GPIO 10: level=0 fsel=6 alt=2 func=DPI_D6
GPIO 11: level=0 fsel=6 alt=2 func=DPI_D7
GPIO 12: level=0 fsel=6 alt=2 func=DPI_D8
GPIO 13: level=0 fsel=6 alt=2 func=DPI_D9
GPIO 14: level=0 fsel=6 alt=2 func=DPI_D10
GPIO 15: level=0 fsel=6 alt=2 func=DPI_D11
GPIO 16: level=0 fsel=6 alt=2 func=DPI_D12
GPIO 17: level=0 fsel=6 alt=2 func=DPI_D13
GPIO 18: level=0 fsel=6 alt=2 func=DPI_D14
GPIO 19: level=0 fsel=6 alt=2 func=DPI_D15
GPIO 20: level=0 fsel=6 alt=2 func=DPI_D16
GPIO 21: level=0 fsel=6 alt=2 func=DPI_D17
GPIO 22: level=0 fsel=6 alt=2 func=DPI_D18
GPIO 23: level=0 fsel=6 alt=2 func=DPI_D19
GPIO 24: level=0 fsel=6 alt=2 func=DPI_D20
GPIO 25: level=0 fsel=6 alt=2 func=DPI_D21
GPIO 26: level=0 fsel=6 alt=2 func=DPI_D22
GPIO 27: level=0 fsel=6 alt=2 func=DPI_D23
BANK1 (GPIO 28 to 45):
GPIO 28: level=1 fsel=0 func=INPUT
GPIO 29: level=0 fsel=1 func=OUTPUT
GPIO 30: level=0 fsel=7 alt=3 func=CTS0
GPIO 31: level=0 fsel=7 alt=3 func=RTS0
GPIO 32: level=1 fsel=7 alt=3 func=TXD0
GPIO 33: level=1 fsel=7 alt=3 func=RXD0
GPIO 34: level=1 fsel=7 alt=3 func=SD1_CLK
GPIO 35: level=1 fsel=7 alt=3 func=SD1_CMD
GPIO 36: level=1 fsel=7 alt=3 func=SD1_DAT0
GPIO 37: level=1 fsel=7 alt=3 func=SD1_DAT1
GPIO 38: level=1 fsel=7 alt=3 func=SD1_DAT2
GPIO 39: level=1 fsel=7 alt=3 func=SD1_DAT3
GPIO 40: level=0 fsel=4 alt=0 func=PWM0
GPIO 41: level=0 fsel=4 alt=0 func=PWM1
GPIO 42: level=0 fsel=4 alt=0 func=GPCLK1
GPIO 43: level=0 fsel=4 alt=0 func=GPCLK2
GPIO 44: level=1 fsel=0 func=INPUT
GPIO 45: level=1 fsel=0 func=INPUT
BANK2 (GPIO 46 to 53):
GPIO 46: level=1 fsel=0 func=INPUT
GPIO 47: level=1 fsel=1 func=OUTPUT
GPIO 48: level=0 fsel=4 alt=0 func=SD0_CLK
GPIO 49: level=1 fsel=4 alt=0 func=SD0_CMD
GPIO 50: level=1 fsel=4 alt=0 func=SD0_DAT0
GPIO 51: level=1 fsel=4 alt=0 func=SD0_DAT1
GPIO 52: level=1 fsel=4 alt=0 func=SD0_DAT2
GPIO 53: level=1 fsel=4 alt=0 func=SD0_DAT3

gpio on stereopi

Code: Select all

BANK0 (GPIO 0 to 27):	
GPIO 0: level=0 fsel=6 alt=2 func=PCLK
GPIO 1: level=1 fsel=6 alt=2 func=DE
GPIO 2: level=0 fsel=6 alt=2 func=LCD_VSYNC
GPIO 3: level=0 fsel=6 alt=2 func=LCD_HSYNC
GPIO 4: level=1 fsel=6 alt=2 func=DPI_D0
GPIO 5: level=1 fsel=6 alt=2 func=DPI_D1
GPIO 6: level=0 fsel=6 alt=2 func=DPI_D2
GPIO 7: level=0 fsel=6 alt=2 func=DPI_D3
GPIO 8: level=1 fsel=6 alt=2 func=DPI_D4
GPIO 9: level=0 fsel=6 alt=2 func=DPI_D5
GPIO 10: level=1 fsel=6 alt=2 func=DPI_D6
GPIO 11: level=0 fsel=6 alt=2 func=DPI_D7
GPIO 12: level=1 fsel=6 alt=2 func=DPI_D8
GPIO 13: level=0 fsel=6 alt=2 func=DPI_D9
GPIO 14: level=1 fsel=6 alt=2 func=DPI_D10
GPIO 15: level=0 fsel=6 alt=2 func=DPI_D11
GPIO 16: level=0 fsel=6 alt=2 func=DPI_D12
GPIO 17: level=0 fsel=6 alt=2 func=DPI_D13
GPIO 18: level=0 fsel=6 alt=2 func=DPI_D14
GPIO 19: level=1 fsel=6 alt=2 func=DPI_D15
GPIO 20: level=0 fsel=6 alt=2 func=DPI_D16
GPIO 21: level=1 fsel=6 alt=2 func=DPI_D17
GPIO 22: level=0 fsel=6 alt=2 func=DPI_D18
GPIO 23: level=0 fsel=6 alt=2 func=DPI_D19
GPIO 24: level=0 fsel=6 alt=2 func=DPI_D20
GPIO 25: level=0 fsel=6 alt=2 func=DPI_D21
GPIO 26: level=0 fsel=6 alt=2 func=DPI_D22
GPIO 27: level=0 fsel=6 alt=2 func=DPI_D23
BANK1 (GPIO 28 to 45):
GPIO 28: level=1 fsel=0 func=INPUT
GPIO 29: level=1 fsel=0 func=INPUT
GPIO 30: level=0 fsel=0 func=INPUT
GPIO 31: level=0 fsel=0 func=INPUT
GPIO 32: level=0 fsel=0 func=INPUT
GPIO 33: level=0 fsel=0 func=INPUT
GPIO 34: level=1 fsel=0 func=INPUT
GPIO 35: level=1 fsel=0 func=INPUT
GPIO 36: level=1 fsel=0 func=INPUT
GPIO 37: level=0 fsel=0 func=INPUT
GPIO 38: level=0 fsel=0 func=INPUT
GPIO 39: level=0 fsel=0 func=INPUT
GPIO 40: level=0 fsel=0 func=INPUT
GPIO 41: level=0 fsel=0 func=INPUT
GPIO 42: level=0 fsel=0 func=INPUT
GPIO 43: level=0 fsel=0 func=INPUT
GPIO 44: level=0 fsel=0 func=INPUT
GPIO 45: level=0 fsel=0 func=INPUT
BANK2 (GPIO 46 to 53):
GPIO 46: level=1 fsel=0 func=INPUT
GPIO 47: level=1 fsel=1 func=OUTPUT
GPIO 48: level=0 fsel=4 alt=0 func=SD0_CLK
GPIO 49: level=1 fsel=4 alt=0 func=SD0_CMD
GPIO 50: level=1 fsel=4 alt=0 func=SD0_DAT0
GPIO 51: level=1 fsel=4 alt=0 func=SD0_DAT1
GPIO 52: level=1 fsel=4 alt=0 func=SD0_DAT2
GPIO 53: level=1 fsel=4 alt=0 func=SD0_DAT3

I'm not really sure what needs rearrangement, can you point it out for me?

[Realizator]

Actually we have dt-blob.bin file in a /boot partition, which redefines some pins for the second camera support. To test a conflict hypothesis, can you please rename this file to, say, “dt-blob1.bin”, and do your test again?
If it will start working, we’ll need to do a pin definition analysis to find a conflict and fix it.

You can find dt-blob.dts (source file of dt-blob.bin) in our wiki to look at our pins definition here: https://wiki.stereopi.com/index.php?tit ... lob.bin.29