# DP

***Copyright © Quectel Wireless Solutions Co., Ltd. 2026. All rights reserved.***

---

This document details the identification, connection methods, system configuration, and troubleshooting for the **DP** display interface on the **Quectel Pi H1** single-board computer. While the DP interface is designed for **DisplayPort (DP)** displays, this document uses an **11.6-inch HDMI display** as an example to demonstrate the DP to HDMI method.

# DP port to HDMI display connection

Follow the diagram below for connection:

```{image} images/image_SjtVbfKmYou2nPxItF2c2mGinld.webp
:width: 2237px
:height: 1279px
```

<div style="text-align: center">
DP Port to HDMI display connection setup
</div>

For specific login operations, please refer to [System login](<../../../Operating system/Debian/System login/System login.md>)

```{image} images/image_VLQYbEtP8oCqNXxdoIec2dWJn3c.webp
:width: 1263px
:height: 784px
```

<div style="text-align: center">
Display interface
</div>

# Function usage

## Adjust display brightness and volume

Note: After connecting an **HDMI** display, the resolution is adaptive and cannot be changed. Currently supported **HDMI** resolutions are **3840 × 2160**, **1920 × 1080**, **1280 × 720**, **720 × 480**

After connecting the **HDMI** display and powering on, enter the **Gnome** desktop, click the battery icon in the upper right corner, and slide the volume bar and brightness bar to adjust volume and brightness.

The following is the operation diagram for adjusting display brightness and volume:

```{image} images/image_ImW1bdkfoojbOGxq7TCcRufMnHh.webp
:width: 1035px
:height: 653px
```

<div style="text-align: center">
Brightness and volume adjustment
</div>

## Touch function usage

After connecting the **DP** to **HDMI** display and powering on, you need to connect the **USB** port to the HDMI display.  
Note: This function requires an **HDMI** display with touch functionality.  
Follow the diagram below for connection:

```{image} images/image_RwwMbiqj6oyxFsxUQB9cWXhqnZg.webp
:width: 2658px
:height: 1279px
```

<div style="text-align: center">
Touch function connection
</div>

## Video playback function usage

**GUI video playback**: Open the **Gnome** desktop, find the video file in the **Gnome** desktop's **File Manager**, and click the video file to play it.  
Note: Double-click the frame to play the video in fullscreen.

```{image} images/image_UlLkbViVRogYX3xi3eqc6ACenYg.webp
:width: 1075px
:height: 650px
```

<div style="text-align: center">
Desktop operation steps
</div>

```{image} images/image_KZy3bMayZocuOnx0gBKcCFUBnqg.webp
:width: 1256px
:height: 760px
```

<div style="text-align: center">
Video playback interface
</div>

**VLC command-line video playback**: When playing via command line, follow these steps to enter the corresponding commands.

```shell
export LIBGL_ALWAYS_SOFTWARE=1 #Modify the environment variable of this window to switch to CPU rendering during video playback
VLC test.mp4                   #Play video
```

The following is the video playback interface diagram:

```{image} images/image_MRaXbD9wsoe0CKxn9DlcnljNnxb.webp
:width: 1256px
:height: 760px
```

<div style="text-align: center">
Video playback interface
</div>

**GST command-line video playback**: When playing via command line, you need to enter the following command.

```shell
gst-launch-1.0 filesrc location=/home/pi/test.mp4 ! qtdemux ! h264parse ! avdec_h264 ! autovideosink    ## The parameter after "location" should be modified according to the actual video file path
```

Command parameter description:

- `gst-launch-1.0`: This is GStreamer's command-line tool for building and running a GStreamer pipeline.

- `filesrc location=/home/pi/test.mp4`: Uses the `filesrc` element to read video files from the specified path `/home/pi/test.mp4`.

- `! qtdemux`: Through the `!` symbol, connects the output of the previous element to the input of the next element. `qtdemux` is responsible for demultiplexing the MP4 container format, separating the audio and video streams within it.

- `! h264parse`: Parses the separated H.264 video stream, reorganizing it into a format suitable for decoder processing.

- `! avdec_h264`: Uses the software decoder `avdec_h264` to decode the H.264 video stream. This is a GStreamer plugin element based on FFmpeg.

- `! autovideosink`: Automatically selects an appropriate video output component to display video content. Depending on the system environment, it selects the most suitable sink (e.g., `waylandsink` for Wayland, `ximagesink` for X11, etc.).

The following is the video playback interface diagram:

```{image} images/image_LmxLbkcmroVUugxGFGMciGk4nLb.webp
:width: 1277px
:height: 794px
```

<div style="text-align: center">
Video Playback Interface
</div>

## Audio playback function usage

**GUI audio playback**: Open the **Gnome** desktop, find the audio file in the **Gnome** desktop's **File Manager**, and click the audio file to play it.  
Note: To play audio, connect speakers to the Quectel-Pi-H1 single-board computer.

```{image} images/image_Agi7b3K7OoFSUTxb5r9clgSQnjd.webp
:width: 1037px
:height: 651px
```

<div style="text-align: center">
Desktop operation steps
</div>

```{image} images/image_TSImbPuNfoD0uGx0t2pc1hwbn0y.webp
:width: 1272px
:height: 796px
```

<div style="text-align: center">
Audio playback interface
</div>

**VLC command-line audio playback function**: When playing via command line, follow these steps to enter the corresponding commands.

```shell
export LIBGL_ALWAYS_SOFTWARE=1 #Modify the environment variable of this window to switch to CPU rendering during audio playback
VLC 1.mp3                      #Play audio
```

The following is the audio playback interface diagram:

```{image} images/image_DCxjbalxaowj03xEmz2cecPxndb.webp
:width: 1272px
:height: 796px
```

<div style="text-align: center">
Audio playback interface
</div>

**GST command-line audio playback function**: When playing via command line, you need to follow the steps below to enter the corresponding commands.  
Note: After entering the corresponding command, the audio playback progress will be displayed in the terminal.

```shell
gst-launch-1.0 uridecodebin uri=file:///home/pi/test.mp3 ! audioconvert ! audioresample ! autoaudiosink ## The parameter after "uri" should be modified according to the actual video file path
```

Command parameter description:

- `gst-launch-1.0`: This is GStreamer's command-line tool for building and running a GStreamer pipeline.

- `uridecodebin uri=file:///home/pi/test.mp3`: Uses the `uridecodebin` element to read and automatically decode audio files from the specified URI path `file:///home/pi/test.mp3`. This is an advanced element that can automatically detect media types and select appropriate demuxers and decoders.

- `! audioconvert`: Through the `!` symbol, connects the output of the previous element to the input of the next element. `audioconvert` is used to convert audio formats, ensuring audio format compatibility between adjacent elements.

- `! audioresample`: Resamples the audio, adjusting the audio sample rate to match the requirements of subsequent elements.

- `! autoaudiosink`: Automatically selects an appropriate audio output component to play audio content. Depending on the system environment, it selects the most suitable audio output device, such as ALSA, PulseAudio, or other available audio backends.

The following is the audio playback interface diagram:

```{image} images/image_K2kkbolv0oAQwcxjLHpc9mtVnSh.webp
:width: 1352px
:height: 792px
```

<div style="text-align: center">
Audio playback interface
</div>

# Application scenarios

- **Media entertainment terminal**: The **Quectel Pi H1** single-board computer can serve as a media entertainment terminal for playing videos, music, and viewing photos.

- **Industrial data visualization platform**: The **Quectel Pi H1** single-board computer can serve as an industrial data visualization platform to display industrial data, monitor device status, and process data.

- **Smart interactive terminal**: The **Quectel Pi H1** single-board computer can serve as a smart interactive terminal for various human-machine interaction applications.

# Troubleshooting

## How to view system logs

To view system logs, you need to connect the serial cable to a computer and use a serial debugging tool to view the logs.

## Black screen issue

After properly connecting the device, if the display shows a **black screen** after powering on, it may be due to the following situations:

1. Power connection issue  
  
Check if the display's power supply interface is properly connected. Confirm that power supply is correctly connected and supplying power.

2. Connection issue  
  
Check if the **HDMI** cable is properly connected and securely inserted. Confirm the **HDMI** cable direction is correct to avoid reverse insertion. Check the connector for physical damage.

3. System startup issue  
  
Confirm the system has started properly and loaded the display service. View system logs to confirm the display driver is loaded properly.

4. Resolution compatibility issue  
  
Check if the resolution supported by the display matches the system output resolution. Manually adjust the resolution settings if necessary.

## Screen artifact issue

After properly connecting the device, if the display shows **screen artifact** after powering on, it may be due to the following situations:

1. Signal interference  
  
Check if the HDMI cable is too long or of poor quality. Confirm whether there are strong electromagnetic interference sources around the cable. Try replacing it with a high-quality HDMI cable.

2. Hardware compatibility issue  
  
Confirm the display model used is fully compatible with **Quectel Pi H1**. Check if the display firmware version is up to date.

3. Poor interface contact  
  
Check the HDMI interface for looseness or oxidation. Unplug and replug the HDMI cable to ensure a firm connection.