Accelerometer

[TyphoonPete]

Can someone please tell me where the accelerometer is located on the H Pro??
If the GPS module (attached to the top panel) is disconnected (about 1 Hour) then reconnected are any previous settings etc lost??
I disconnected the GPS module when fitting new upper and lower body pieces.
When I attempted to initiate a hover in my yard after completing the work (to test all was good...which it wasn't) she had a fit and tried to reach escape velocity and head to Mars.
Due to the fact she destroyed 2 props and "damaged" the rest, and a new set will be at least a week I can only sit and ponder what may be the problem or what I did or didn't do.
I will be doing a full recalibration before the next attempt at lift-off in a wide open space, which in retrospect I should have done before attempting the hover.
Any and all assistance much appreciated
cheers and seasons greetings to all
Pete

 

[dylanfm]

I believe the accelerometer is located between the power distribution board and the flight control module that plugs into the power distribution board connected by a small ribbon cable. I don't really think that is the problem if by "head to Mars" you mean that it went into an uncontrolled climb.

Re-calibrating everything is a good idea. Are you sure to mounted the GPS in the exact same orientation as before? Not rotated 180deg or upside down?

 

[PatR]

The compass is colocated with the GPS unit. If you happened to use a magnetized hex key, screw drivers, or other tools when working around the GPS the previous compass calibration would have been ruined. If any of the tools used can generate any level of pull on the screws it was magnetized, something that frequently occurs with tools, especially those that use twisting/rotational force, used in homes. The use of tools in this state is very hard on sensitive electronics and good reason to obtain a set of non magnetic tools for use if we intend to work on PC boards.

Another concern when working on computers or other devices that employ printed circuit boards, transistors, or chips is a thing called static discharge. If skin contact caused a static discharge (you’ve experienced this as a small electrical shock when touching a metal door knob) it’s possible some electrical component on a board could have been destroyed. Those little discharges can generate tens of thousands of volts. The aerospace and computer industries have lost a lot of money in damaged components this way, with most all manufacturers of computer components adopting very stringent ESD protocols to prevent static discharge. Employees are required to take ESD prevention courses annually.

I suspect the accelerometers are built into the flight control module as that is where they are with standard Pixhawk flight control systems. Note, there are multiple accelerometers as they need to sense pitch, roll, yaw, and gravity independent of each other.

 

[Steve Carr]

I disconnected the GPS module when fitting new upper and lower body pieces.

The GPS/Compass module has a tiny rechargeable battery so you should not lose any information store there. The connecting cable to that module is twisted to reduce interference. You must make certain that remains that way when reinstalling it. Also the retaining screws are brass. If you lose any of those you must replace them with brass or, in a pinch, aluminum, but never steel.

When you do your next test flight and have completed the calibrations, allow the H to sit for about 12 min in order to allow the GPS to complete the updates. Wait until you see at least 15 satellites on the display.

 

[The_caged_bird]

Good thread, good info. We had screwdrivers made of non-ferrous metal in the Navy, they wore out rather quickly but they would not ever become magnetic. We also had grounding bracelets when we did the 3M stuff on the component level.

What I wanted to add was that while yes, you'd want to choose a large open area to test your H, if you have another uncontrolled climb, it's gone. I mean, I figure that whatever broke your props during your flyaway saved the drone from being lost. I'd pay $50 to keep from losing $500 any day.