Using Raspberry Pi official 7 inch display with DietPi

Troubleshooting
1

I’m using the DietPi image on Rock Pi 4b and booting into chromium in kiosk mode. My official Raspberry Pi 7 inch touchscreen (800x480) is connected to 5V + GND and DSI MIPI with the ribbon cable. My kiosk appears when I have an HDMI monitor connected, however, there’s no activity, no backlight, nothing, when I’m trying to use the touchscreen the touchscreen. Unlike the Raspberry Pi 4 image, there’s no configurable options for the display within dietpi-config on the Rock Pi 4b image, so I need to know exactly how I should configure DietPi to detect the display.

I’ve installed the rockpi4-dtbo package and created /boot/hw_intfc.conf with the line intfc:dtoverlay=raspberrypi-7-inch-lcd uncommented. I’ve tried adding overlays=raspberrypi-7-inch-lcd to /boot/armbianEnv.txt but none of these attempts have worked so far. Thanks in advance.

2

Hmm, does this “raspberrypi-7-inch-lcd.dtbo” overlay exist in /boot/dtb/… ?

Edit: It does not. Check /boot/dtb/rockchip/overlay/. The readme gives some more details:

This document describes overlays provided in the kernel packages
For generic Armbian overlays documentation please see
https://docs.armbian.com/User-Guide_Allwinner_overlays/

### Platform:

rockchip (Rockchip)

### Provided overlays:

- i2c7, i2c8, pcie-gen2, spi-spidev, uart4, w1-gpio

### Overlay details:

### i2c7

Activates TWI/I2C bus 7

I2C7 pins (SCL, SDA): GPIO2-B0, GPIO2-A7 GPIO1-C5, GPIO1-C4

### i2c8

Activates TWI/I2C bus 8

I2C8 pins (SCL, SDA): GPIO1-C5, GPIO1-C4

### pcie-gen2

Enables PCIe Gen2 link speed on RK3399.
WARNING! Not officially supported by Rockchip!!!

### spi-jedec-nor

Activates MTD support for JEDEC compatible SPI NOR flash chips on SPI bus
supported by the kernel SPI NOR driver

SPI 0 pins (MOSI, MISO, SCK, CS): GPIO3_A5, GPIO3_A4, GPIO3_A6, GPIO3_A7
SPI 1 pins (MOSI, MISO, SCK, CS): GPIO1_A7, GPIO1_B0, GPIO1_B1, GPIO1_B2
SPI 2 pins (MOSI, MISO, SCK, CS): GPIO1_C0, GPIO1_B7, GPIO1_C1, GPIO1_C2
SPI 3 pins (MOSI, MISO, SCK, CS): GPIO2_B2, GPIO2_B1, GPIO2_B3, GPIO2_B4

Parameters:

param_spinor_spi_bus (int)
	SPI bus to activate SPI NOR flash support on
	Required
	Supported values: 0, 1, 2

param_spinor_max_freq (int)
	Maximum SPI frequency
	Optional
	Default: 1000000
	Range: 3000 - 100000000

### spi-spidev

Activates SPIdev device node (/dev/spidevX.Y) for userspace SPI access,
where X is the bus number and Y is the CS number

SPI 0 pins (MOSI, MISO, SCK, CS): GPIO3_A5, GPIO3_A4, GPIO3_A6, GPIO3_A7
SPI 1 pins (MOSI, MISO, SCK, CS): GPIO1_A7, GPIO1_B0, GPIO1_B1, GPIO1_B2
SPI 2 pins (MOSI, MISO, SCK, CS): GPIO1_C0, GPIO1_B7, GPIO1_C1, GPIO1_C2
SPI 3 pins (MOSI, MISO, SCK, CS): GPIO2_B2, GPIO2_B1, GPIO2_B3, GPIO2_B4

Parameters:

param_spidev_spi_bus (int)
	SPI bus to activate SPIdev support on
	Required
	Supported values: 0, 1

param_spidev_spi_cs (int)
	SPI chip select number
	Optional
	Default: 0
	Supported values: 0, 1
	Using chip select 1 requires using "spi-add-cs1" overlay

param_spidev_max_freq (int)
	Maximum SPIdev frequency
	Optional
	Default: 1000000
	Range: 3000 - 100000000

### uart4

Activates UART4

UART4 pins (RX, TX): GPIO1_A7, GPIO1_B0

Notice: UART4 cannot be activated together with SPI1 - they share the sam pins.
Enabling this overlay disables SPI1.

### w1-gpio

Activates 1-Wire GPIO master
Requires an external pull-up resistor on the data pin
or enabling the internal pull-up

Parameters:

param_w1_pin (pin)
	Data pin for 1-Wire master
	Optional
	Default: PD14

I guess its an i2c touchscreen? Then you would need to add the i2c7 or i2c8 overlay, depending on which pins the touchscreen is added to. But to be true I have not much idea if there are other drivers required that are present on RPi but not on ROCK Pi 4 by default.

3

strangeways,

do you have any luck with the screen, I have the same problem.
7" toutch with dsi mipi.
no config for dsi in dietpi-config?

no proper overlay in bullseye (i think…?)

help would be nice…

4

It highly depends on the SBC btw, RPi and Armbian based images ship with a very different kernel and device tree overlays.

Generally the manufacturer of the LCD should provide info on how to install it on Linux, often specifically on how to do so on RPi, often these work well OOTB. On RPi, AFAIK the DSI port is enabled OOTB, not sure on Armbian based images, whether a device tree overlay needs to be enabled in cases.