DroneTag Community

zhanghaijason

This may happen if you are using onboard flash for params saving, as px4 onboard flash driver not handling it well.
Recommended solution is to use a TF card as param storage. SD driver performs much more solid.

rolandash Hi, finally I save my parameters into my pc drive. However, today, it reset again after a failsafe initiation. It fell from about 2m high on carpet. I think the falling, the impact was not that bad. But it reset again. The worse thing is that after I load the parameters from the drive. I cannot arm the drone anymore. At first I thought it damaged the 4 in 1 ESC. So changed a new ESC. But it still behaved the same. It behaves like: if it is the first arm from remote controller, the motors will rotate 0.5s I think, and stop. If I tilt the drone forward, only 2 forward motors can rotate at a very low speed. If titled backward, the back 2 motors will rotate. After the mindracer signal LED blinks white, which means disarm after arm if no extra signal received, there will no signal anymore.

I recalibrate the radio, it still behaves the same. So I think the radio, controller, and ESC should be good. Do you know what is the possible reason? Is it the power distribution board or the mindracer (the mindracer LED behaves normal I believe). I also ordered both pdb and mindracer. Hope they can arrive soon.

zhanghaijason

I am not sure I understood what you did. I guess you probably misunderstood my advice. Saving params into computer drive off-board won't resolve your problem, as MindRacer will still load the problematic params from onboard flash during flying.
The point is to insert a TF card into MindRacer's card slot, like in below's image,

and use this TF card as storage for params, instead of the default onboard flash chip.

The onboard flash chip maybe physically defected due to high temperature when you do soldering, or can because of un-stable px4 flash driver, both can result in wrong param values reading. Using an TF card instead can isolate these possibilities.

Saving

rolandash Hi Thanks for the clarification. I have been using the TF card, is there any settings I need to change to make the parameters saved in the TF card? Do I need to do something or as long as it can detect the TF card, it can save the params into the TF card? If it is automatically, then I think it doesn't work for my case since I have been using the TF card the first day I received the mindracer.

And for my last reply is a different question. I posted here is because I am wondering if it is related to the parameter reset or not. The problem in the last reply is that now the ESC is not controllable. I can not arm the drone. Do you have any idea what's the possible reason? Thanks

zhanghaijason

ok sry I did forget few lines in px4 src needs to be changed in order to do that.
Please locate file ROMFS/px4_common/init.d/rcS, and find the line
if mtd start
and replace this if-fi block with following:

set PARAM_FILE /fs/microsd/params
if [ -f $PARAM_FILE ]
then
else
if mtd start
then
set PARAM_FILE /fs/mtd_params
fi
fi
re-compile and upload the new firmware.
If your TF card is clean (require FAT32 formatted first of course), all calibration tabs will be red on next boot up. and you can do a fresh calibration from the beginning.

zhanghaijason

The question in your last reply may have relation with param reset. So let's see what will happen after TF card param works.

rolandash I think nothing changed. Yes, it was pretty good. I will try to compile the firmware and upload. Thanks for your help!

rolandash Hi I followed your guide and it worked. Thank you very much!