I have been using Tower3d Pro for 2 weeks. I have purchased six DLC airports. Love the SIM.
Like so many, I don't like using the Left Shift button for Push To Talk (PTT). I looked at Keyboard Macros, registry hacks, etc.
I have a background in electronics, so I went hardware. I took an old (NEW) Wired USB Keyboard apart. They use an XY matrix to push contacts for each key. The module that runs the keyboard is about 1"x2". It has 16 contacts (8 x 12). I was able to find out which pads operate each key. With some experimenting I found the Shift Key. So plugging in the "SECOND" USB Keyboard, I hooked some wires to the contacts, and "IT WORKS". You can probably use any old keyboard. Each will have some type of contacts. So I plan to make an actual PTT BUTTON like controllers use. In addition, I could hook up a foot pedal as an alternative.
I was going to hack an Arduino for a HID (Human Interface Device). There are quite a few articles on how to do this.. I work for an I.T. company, and we have dozens of space keyboards. Our local Microcenter sells cheap keyboards for about $4.00. Just thought if anyone wanted to try this, they can. I am sure now I figured this out, FT will probably include an alternate Key on the next release. Oh Well Just want to contribute to the community that brings me so much joy.
Sorry for the lousy job, but this was a "PROOF OF CONCEPT". I will clean it up and post a better picture. Maybe I'm taking this hobby a little to serious. But I love it!!!