"Here is where I read about the software interface:
http://dev.3dr.com/hardware-gimbalbay.html#software-interface"

"Here are logs for 3.2.1 and a 3.3 tests. This particular 3.3 test drifted 5 meters.2015-04-01 15-15-44-fm-3.2.1.log2015-03-31 20-41-22-fw-3.3.log"

"For 3.3, the initial pre-arm calibration doesn't seem to bring the altitude to 0 and the altitude goes very (10-20m) negative during hover testing. I'll post a log of my test with 3.3."

"Thanks for the response. I did get it to work. Here are a couple of things that threw me off:

1.) rssi in the rc_channels_raw message had to be divided by 255 and then multiplied by the rssi_range. I was expecting a number between 0 and 100. The…"

"If I specify that RSSI_PIN=103 and RSSI_RANGE=5 and then connect a 1.5 V battery between the ground pins and the sensor pin on the SB slot of the Pixhawk, shouldn't I see an RSSI of 30 in the RC_CHANNELS_RAW message? Right now, I'm seeing a small…"

"BTW, during my ground hover testing, I noticed that the altitude is varying by 10-20 meters for the latest 3.3 version. It seems much better in the 3.2.1 release with a variation of about a meter during hover."

"Andy,
Thanks so much, that was the problem. I've never had to muck with this setting and didn't even know it existed. I guess I need to read the entire Spektrum manual to see what else I'm missing!…"

"I tried this test out with 3.2.1 on my APM with a Spektrum AR5200 receiver and DX7 Transmitter. It responded correctly by setting rc3 to 900 when the R/C transmitter was turned off.

Has anybody with a Pixhawk seen the behavior described above where…"

"I posted this on the other related thread, but haven't heard back:
http://diydrones.com/profiles/blog/show?id=705844%3ABlogPost%3A1903...

I've done tests with 3.2.1 and 3.3 and find that the rc channels continue to register values above 1000 when I…"

"I may have had a race condition that caused the issue.  I tried an experiment where I issued a mission_clear_all and then immediately set the mode to AUTO and got the firmware to go into AUTO. (If I had an empty mission to start with, I could not…"

"With the issues with the barometer and GPS, especially close to the ground, it seems like lidar or radar would be a more reliable solution for altitude measurements. I noticed that 3DR has a lidar coming that looks…"

"Thanks for your support Randy, you've been a great help over the years!  Its been great to see the project flourish!

I actually told the copter to LAND myself as well with MAVLINK then the pilot with the R/C switched it to RTL. (Switching to…"

"I was flying with 3.2, but it appeared to go into AUTO mode when there were was no mission defined. (The mission waypoints aren't in the log file right, you can only retrieve them from the copter via MAVLINK?)"