Type-C DP 1.4a

../../../../_images/axon-dp.webp

Axon provides 2x multiplexed Type-C DisplayPort 1.4a interface for high-resolution display output with support for multiple displays and high video bandwidth. The DP connector on RK3588 is used for direct connections to DP-compatible displays, projectors, and USB-C docking stations.

Getting Started

Prerequisites

  • Type-C DisplayPort 1.4a compatible display, or monitor

  • Axon with DP connector

  • USB-C cable to your display port(HDMI , VGA , others) in your display

How to use

  1. Connect one end of your USB-C cable to axon board to the usb-ports shown in image

  2. Connect the other end of your USB-C cable to your display

  3. You should get the Vichrak configured displayed on your monitor

Configure DisplayPort and video mode

1. Check if Display is detected

Use xrandr to show all supported resolutions and refresh rates available on DP output:

xrandr

Example output:

Screen 0: minimum 320 x 200, current 1280 x 1024, maximum 16384 x 16384
HDMI-1 disconnected (normal left inverted right x axis y axis)
HDMI-2 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
DP-2 connected 1280x1024+0+0 (normal left inverted right x axis y axis) 376mm x 301mm
   1280x1024     60.02*+  75.02
   1152x864      75.00
   1024x768      75.03    60.00
   800x600       75.00    68.32
   640x480       75.00    59.94
   720x400       70.08
Key Information from Output
  • Here, DP-2 is shown as connected, which shows that your display has successfully connected to axon

  • Numbers on right = Available refresh rates in Hz

  • connected = Display is detected and connected

  • disconnected = Display not detected

3. Set Custom Resolution and Refresh Rate

Note

Actual supported resolutions depend on the capabilities of the connected display and the configured DP lanes.

Manually configure display resolution and refresh rate:

xrandr --output DP-2 --mode 1280x1024 --rate 60
Common xrandr Parameters

Parameter

Description

--output <name>

Display output name (DP-1, DP-2, HDMI-1, etc.)

--mode <resolution>

Resolution in format WIDTHxHEIGHT (e.g., 1280x1024)

--rate <frequency>

Refresh rate in Hz (e.g., 60)

--auto

Auto-detect and apply optimal settings

--off

Disable the display

--scale <factor>

Scale output (e.g., 1.0 for normal, 2.0 for 2x zoom)

DP Connector-Split Mode

Axon supports DP connector-split mode. When enabled, 2 USB-C DisplayPort connector can output split screen(50:50) to two external monitors . This feature behind the scene still uses same video port, so using this users can use more than 4 display screen on axon , if using all ports you can connect 6 screens.

Hardware Requirements

To use DP connector-split mode, the following hardware is required:

  • Two USB Type-C to Display cable

  • Two external monitors

After making the connection and booting the device follow below config guide

Steps to follow for Configuration

  1. Open a terminal window (Ctrl+Alt+T).

  2. Run command sudo vicharak-config in it.

  3. Select Overlays options in it by pressing enter key.

┌───────────────────────────────────┤ VICHARAK_CONFIG ├────────────────────────-───────────┐
│ Please select an option below:                                                           │
│                                                                                          │
│                                   System Maintanince                                     │
│                                       Hardware                                           │
│                                       Overlays                                           │
│                                     Connectivity                                         │
│                                   Advanced Options                                       │
│                                     User Settings                                        │
│                                     Localization                                         │
│                                         About                                            │
│                                                                                          │
│                      <Ok>                               <Cancel>                         │
│                                                                                          │
└──────────────────────────────────────────────────────────────────────────────────────────┘
  1. You will see Warning Page, click on yes and select Manage Overlays options.

┌───────────────────────────────────┤ VICHARAK_CONFIG ├────────────────────────────────────┐
│ Configure Device Tree Overlay                                                            │
│                                                                                          │
│                                Manage overlays                                           │
│                                View overlay info                                         │
│                                Install 3rd party overlay                                 │
│                                Reset overlays                                            │
│                                                                                          │
│                                                                                          │
│                      <Ok>                               <Cancel>                         │
└──────────────────────────────────────────────────────────────────────────────────────────┘
  1. Select overlay Enable DP connector-split mode Axon V0.3 by pressing spacebar on keyboard, then select Ok.

┌──────────────────────────────────┤ VICHARAK_CONFIG ├─────────────────────────────────────┐
│ Please select overlays:                                                                  │
│                                                                                                         │
│  [*] Enable DP connector-split mode Axon V0.3                                            │
│  [ ] Enable RasPi Camera V1.3 (OV5647) on CSI0 Alpha Axon V0.3 [OFF]                     │
│  [ ] Enable RasPi Camera V1.3 (OV5647) on CSI1 Alpha Axon V0.3 [OFF]                     │
│  [ ] Enable RasPi Camera V1.3 (OV5647) on CSI1 Alpha Axon V0.3 [OFF]                     │
│  [ ] Enable RasPi Camera V1.3 (OV5647) on CSI1 Alpha Axon V0.3 [OFF]                     │
│  [ ] Enable RasPi Camera V1.3 (OV5647) on dphy RX0 Alpha Axon V0.3 [OFF]                 │
│  [ ] Enable RasPi Camera V1.3 (OV5647) on dphy RX1 Aplha Axon V0.3 [OFF]                 │
│  [ ] Enable I2C1 on 30-Pin GPIO Header Axon V0.3                                         │
│  [ ] Enable I2C2 on 30-Pin GPIO Header Axon V0.3                                         │
│  [ ] Enable I2C5 on 30-Pin GPIO Header Axon V0.3                                         │
│  [ ] Enable I2C7 on 30-Pin GPIO Header Axon V0.3                                         │
│  [ ] Enable PWM0 on 30 Pin GPIO Header Axon V0.3                                         │
│  [ ] Enable PWM1_M0 on 30 Pin GPIO Header Axon V0.3                                      │
│  [ ] Enable PWM1_M0 on 30 Pin GPIO Header Axon V0.3                                      │
│  [ ] Enable UART1 on 30 Pin GPIO Header Axon V0.3                                        │
│  [ ] Enable UART4 on 30 Pin GPIO Header Axon V0.3                                        │
│  [ ] Enable UART6 on 30 Pin GPIO Header Axon V0.3                                        │
│  [ ] Enable Waveshare 4inch DSI LCD DPHY TX0 Axon V0.3                                   │
│  [ ] Enable Waveshare 4inch DSI LCD DPHY TX1 Axon V0.3                                   │
│                                                                                          │
│                                                                                          │
│                                                                                          │
│                                                                                          │
│                     <Ok>                         <Cancel>                                │
│                                                                                          │
└──────────────────────────────────────────────────────────────────────────────────────────┘
  1. To return back to terminal, press the Esc key until you exit from it.

  2. In order to enable your configuration, Restart your computer or Run command sudo reboot in terminal.

Troubleshooting

  • If dmesg reports inability to initialize DP, verify:

    • Type-C DP cable and connector integrity

    • Correct overlay name and that the overlay is loaded

    • Kernel supports DP output

    • External display is powered on and set to the correct input

  • If the display remains dark, check that:

    • DP display is properly detected in xrandr

    • A valid framebuffer is assigned (fb0, fb1, etc.)

    • Display resolution is supported by the connected monitor

  • Review documentation for model-specific DP timing and initialization sequences

  • Use xrandr to manually set display resolution and refresh rate:

    xrandr --output DP-1 --mode 1920x1080 --rate 60