As I write this the brain hardware is 90% complete but lots of software still needs to be written.

To test the altimeter I needed to build a little vacume chamber.

If is shown below with the brainboard read to begin a test....

It is a 4" PVC pipe capped on one end.

The hardware shown at the end of the pipe is the computer interface adaptor, and the bolts that go through the

pressure vessel to cary power in and data out....

 

Note that the Unit is sitting on a rubber drain stopper, this seals the bottom of the chamber.....

It is shown in operation below....I use an automotive vaccume tester to pump it down. In the picture I'm

pulling 15" Hg of vacume this is about 18,000 ft.