This is a preview version of the DisplayLink DL-7450 Software Development Kit Documentation. The functionality that is described and made available in this version is subject to addition, removal or change without warning.

Deploying code

When you receive your evaluation DL-7450 board, you will also receive some pieces of information that are required to deploy code to the board using the DisplayLink development server. Your account is identified by the following tokens:

ENTERPRISE-ID: This is a token to identify the entity that owns the DL-7450. It is unique to your organisation, and serves to ensure that code can only be deployed to docks that you own.
APPLICATION-KEY and APPLICATION-SECRET: You can think of these as a username and password. They are secrets that are used as authentication tokens. They will be provided to you securely via the usual mechanisms for distributing DisplayLink artefacts to customers. Please treat these tokens as secret and do not distribute to anyone who is not authorised to deploy code to the DL-7450 evaluation board.

In addition, you will be provided with a dock identifier, that looks like

DOCK-ID = "BC385DB79E2B94DC70E44422FCFFB29C0D90FCA7F024AC72625D7376233CFC02"

Send code

With these four pieces of information, the samples/send_code.py script can be used for deploying code to the board:

python3 ./scripts/send_code.py \
   -k <APPLICATION-KEY> \
   -s <APPLICATION-SECRET> \
   -e <ENTERPRISE-ID> \
   -d <DOCK-ID> \
   -f myapplication.py

You are free to design your own mechanism to deploy the code, based on this script. For completeness we provide a description of the deployment process. Code is sent to a DL-7450 by making an HTTP POST request to a REST endpoint in the DisplayLink development server, located at https://sandbox.vision.synaptics.com. There are two steps.

First, obtain an access token for your account. To do this, you need to POST the three tokens mentioned above to the login endpoint: api/isv/application/login. The body of the POST request should be a JSON string:

{
   "data":{
      "type":"isvApplicationLogin",
      "attributes":{
         "clientId":<APPLICATION-KEY>,
         "clientSecret":<APPLICATION-SECRET>,
         "enterpriseId":<ENTERPRISE-ID>
      }
   }
}

If the credentials are correct, the HTTP response will have status code 201, and the body will be a JSON data structure:

{
   "data":{
      "id":"1527b40212abb118a6d83a15",
      "type":"isvApplicationAuth",
      "attributes":{
         "accessToken":<ACCESS-TOKEN>
      }
   },
   "meta":{
      "createdTimestamp":1588220310000
   }
}

The Access Token must be provided as an Authorization header in calls to deploy code:

` Authorization: Bearer <ACCESS-TOKEN> `

See scripts/send_code.py for an example using the Python requests module.

In order to send a Python application, it must be Base64 encoded. In scripts/send_code.py, the application code is read from a file as a byte string and then Base64 encoded, like this:

import base64

with open("application.py", "rb") as f:
code = f.read()

CODE_TO_DEPLOY = base64.b64encode(code).decode("utf-8")

This is the correct form for transmitting the code to the dock via the docks\application\code endpoint. The request body should look like this:

{
   "data":{
      "type":"applicationCode",
      "attributes":{
         "dockId":<DOCK-ID>,
         "code":"CODE_TO_DEPLOY"
      }
   }
}

Send text message

You can also send a text message to the dock. The message is displayed on the splashscreen. The message is sent to the docks\application\message endpoint. The request body should look like this:

{
   "data":{
      "type":"applicationMessage",
      "attributes":{
         "dockId":<DOCK-ID>,
         "message":"TEXT_MESSAGE_TO_DISPLAY"
      }
   }
 }

Warning

Please make sure that the sent message starts with t. Otherwise, the message will not be consumed by the started application on the dock.

The scripts/send_text.py script can be used to send a text message to the dock:

python3 ./scripts/send_text.py \
   -k <APPLICATION-KEY> \
   -s <APPLICATION-SECRET> \
   -e <ENTERPRISE-ID> \
   -d <DOCK-ID> \
   -t "Hello, World!"

Send image

You can also send an image to the dock. The image is displayed on the splashscreen. The image is sent to the docks\application\image endpoint. The request body should look like this:

{
   "data":{
      "type":"applicationMessage",
      "attributes":{
         "dockId":<DOCK-ID>,
         "message":"RAW_IMAGE_DATA"
      }
   }
 }

Warning

Please make sure that the raw image data starts with i. Otherwise, the image will not be consumed by the started application on the dock.

The scripts/send_image.py script can be used to send an image to the dock:

python3 ./scripts/send_image.py \
   -k <APPLICATION-KEY> \
   -s <APPLICATION-SECRET> \
   -e <ENTERPRISE-ID> \
   -d <DOCK-ID> \
   -t <LOCAL_PATH_TO_IMAGE_FILE>