I have another Pinewood Master user that discovered Bill V's Derby Timers where he found instructions about how to inexpensively build his own timer based on the Arduino Uno single board micro-computer.
The Arduino software Bill supplies was originally designed to work with the Windows based race manager software that Bill also created. To work with Bill's software the Arduino sends status messages that Pinewood Master doesn't use and outputs the time message in a format not compatible with Pinewood Master. But, on request, Bill will modify his Arduino software to be compatible with Pinewood Master. This way, in the Pinewood Master preferences, you can select "Fast Track" as your timer, and Pinewood Master can receive times from Bill's timer.
This means that if you get a timer from Bill, (or make your own based on his design) just tell him that you will be using Pinewood Master for your Race Manager software and he can modify the software accordingly.