The dGPS and compass require specific software for them to be used with the EV3. Both sensors have their own programming block, which allows you to program the third-party sensor like you would program a standard EV3 sensor. Thankfully, the software is available for download for free from the manufacturers' websites. All we need to do is follow a few steps to download the third-party software and import it into the EV3 programming environment.

The steps for installing the Dexter Industries and HiTechnic software are the same, so we will start with the Dexter Industries software. All of Dexter Industries' software is available on their GitHub repositories. We will need the software from their EV3 repository, which you can access here: https://github.com/DexterInd/EV3_Dexter_Industries_Sensors.

After you have found the repository, follow these steps to import the Dexter Industries software into your EV3 programming environment:

1. Download the Dexter Industries repository from GitHub. After the download finishes, extract the files and save them to a destination on your computer.
2. Start the EV3 software and open to a new project. Navigate to the toolbar and select Tools | Block Import and Export Wizard.
3. Click the Browse button in the wizard. Navigate to the destination where you saved the software you extracted earlier. Open the folder containing the Dexter Industries firmware; select the file named Dexter.ev3b and click OK.
4. The Block Import and Export wizard will now show that the Dexter.ev3b file is selected and is ready to be imported. Click the Import button at the bottom-right corner of the wizard:
   
5. You will receive a message that indicates whether the import was completed successfully. If so, then the final step is to restart the EV3 software so the changes can take effect. The next time you start the software and open a project, the Dexter Industries blocks will appear in the sensor block palate.

The programming blocks for all of the Dexter Industries blocks are included in the file that we imported. We will only need the dGPS block, so you can ignore the rest of the blocks for this project.

We will follow the same steps to import the HiTechnic programming blocks into the EV3 software. The download can be found at http://www.hitechnic.com/file.php?f=841-HiTechnicEV3Blocks.zip and the name of the file we need to download is 841-HiTechnicEV3Blocks.zip. Each of the HiTechnic sensor blocks is separate, so when you select the file to import in step 3, choose HTCompass.ev3b to import the software for the compass sensor.

After you finish importing the programming blocks, you sensor palate will expand to include the new third-party blocks you added. These blocks are ready for use, which means that we can start writing our programs.