"Gonna keep this going... someone has to have an answer...

I have the 3DR Flow Camera and a Lightwave SF11 rangefinder.   Both are supported in PX4.
I have Flow on I2C and Lightwave on Serial 4/5.
In the QGroundcontrol Analyze widget:…"

"Can you describe what you mean?  What is behavior?
Marvin Tariye said:
It now can takeoff but it's really hard to control ."

"It wont necessarily flip. I know cause I had a flat spinning drone that would escalate quickly. It can have one motor moving air down, but its backwards and causing yaw to be wrong."

"A motor is spinning the wrong way, a prop is wrong, etc. When it spins out of control its because the computer is trying to stop it but the backwards motor or prop is doing the opposite effect."

"Bringing this back up.  I have the latest QGroundcontrol with the new battery calculator on the Power page.
I also have a Power Meter inline on the drone.  Here are the numbers I registered:

Battery:  5200mAh, 3S, 11.1V, 15C

454.4 Wp (
28.2 Wh…"

"2 things to check first.
Did you calibrate the sensors properly?  Is level set while in frame?
Are you positive all the motors and props are spinning the correct direction, and you have the right props on the right motors?

I had a misbehaving…"

"Thanks for the heads up!  I will be on the lookout!"

"I have been looking into this for quite a while but no luck.  I have seen this same question posed a million times on the net, but no one seems to have an answer that is clear.  There are also many YouTube videos of successful indoor / no GPS…"

"It's a 3 month old Turnigy Graphene battery.  But yes, shortly after I started having issues, I lost 1 of the 3 cells.  Seems like it may have been going South, which caused the false readings and red LED.  New battery coming Thursday, so I will…"

"It seems my battery optimization settings in QGC were incorrect, causing a battery low / critical warning.  I saw this in the log file on the SD card.  I messed around with those setting and the RED LED and beeping went away.

Now - I don't know…"

"Yes - I am not in front of QGC right now.  But the main things were setting the battery size to 5200mAh, and the scaling offsets were set to -1.0, which I changed to just 0.  I really don't know what to set them to, so just guessed.
I don't know why…"

"I am waiting for another battery to show up.  Changing the battery paramters DID make the issue go away.  However, immediately after that, I lost one of the cells in the 3S battery, so its dead.

When the new battery arrives in a few days, I will…"

"Hi George - I am trying to figure out how to do that now.  Looks like in QGroundcontrol, under Parameters / Battery Calibration, I just need to manually enter values?  Or is there some automated process to do this?

Thanks!

Derek"

"I also have the PX4 Optical Flow Camera, Pixhawk, and PX4 software.  I can't find any resource to let me know how to get it to function.  It all lights up, using the I2C cable to pixhawk, but it clearly is not functioning as intended.  Therefore, I…"

"For what it's worth, I have the same issue.  All is good on the ground with a 100% charged battery, but then after 10 seconds in the air, I get a RED main LED and a constant beep.  SD card has some log files showing 'Battery Low' and Battery…"