MediaPortal supports remotes from Digital Everywhere tuners like the FireDTV. 

Configuration Settings

Use MediaPortal Configuration to enable support for the FireDTV remote. Open the Remote\FireDTV Tab to start configuration.

• Use FireDTV receiver - Enables or disables FireDTV support
• Extended Logging - Writes information to the MediaPortal log file to assist in debugging. This is especially useful when testing new key mappings.
• Mapping - Opens the Input Mapping Editor. Here you can adjust your button mappings to fit your own needs and reset to default mappings if necessary.

Receiver Settings

Multiple FireDTV remotes can be used.  If you have more than one card, select the one that has the receiver connected.

How do I Use FireDTV in x64 OS?

First you have to download and install FireDTV Viewer.

Extract the 32 bit version of 'FiresatApi.dll' from the zip file (Tools\x86\FiresatApi.dll) and copy it into the FireDTV instal folder.