APM 1.4 won't boot up by power through esc

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1

Hi,

I decided to put the APM 1.4 I had laying around in a bixler2.
I had everything working (even got minimosd to work after a lot of frustration), but all of a sudden the apm won’t power up when I connect my battery. A bit strange, cause I never had this problem.

Some thing about the sutiation:

  • When I plugin the usb it boots up normally
  • When I power up by usb, then esc, then remove usb it shuts down (saw some some posts about APM 2.5 in the same situation, that keeps running after usb is disconnected)
  • when esc is connected a blue led on the oilpan lights up and a red one the APM (see photo)
  • esc provides 5v, and the complete rc rail (where the servo’s connect) is provided with 5v
  • tried another esc that I know that works, same result
  • sj1 jumper was/is soldered (even resoldered to rule out)
  • APM receives radio input (radio calibration in mission planner works fine)
  • I loaded the recommended bixler parameters I found on the ardupilot site. Not absolutely sure if the problems started after I uploaded these, but could be…)

I don’t think the problem is the parameters, cause the apm boots up through usb.

I know I could power the apm through a separate battery by unsoldering the SJ1, but all my batteries are 3s and the they recommend a 2S-pack (7-11V). I would rather not use an extra battery…

Every idea is welcome.

Thanks,
Rutger

2

Not an expert on the 1.4 but sounds like a diode issue, you can power across from the other side perhaps using a UBEC.

3

Thanks for thinking with me, I appreciate it

The APM has direct input pins, but these require 7V to 11V.
What is the best way to achieve 7V, because all the BEC’s i see are 5 or 6V.

4

@Rutger,
I have always split the power rails on my AMP1.4s: diydrones.com/profiles/blogs/sim … power-hack
I use a BEC to power the APM and the R/C receiver and the BEC in the ESCs to power the servos.
Chances are the either the Schottky diode or the fuse connecting the output power bus to the input power bus has failed.
Regards,
TCIII ArduRover2 Developer

5

[quote=“TCIII”]@Rutger,
I have always split the power rails on my AMP1.4s: diydrones.com/profiles/blogs/sim … power-hack
I use a BEC to power the APM and the R/C receiver and the BEC in the ESCs to power the servos.
Chances are the either the Schottky diode or the fuse connecting the output power bus to the input power bus has failed.
Regards,
TCIII ArduRover2 Developer[/quote]

Look promising.
So if I’m correct by directly powering the APM through a BEC my problem should probably be solved and as a bonus I get a saver setup.
Could you tell me what BEC you are using? I use 3S lipo’s

And just a thought, but couldn’t I use the powerhack without cutting the trace on the 5V rail?
That way I wouldn’t be needing an extra BEC.

Regards,
Rutger

6

@Rutger,
Any quality BEC of around 3 amps that can handle a 3S LiPo will work. I have used Hobby King and Turnigy. They are all made in China. The more they cost the better they are usually.
Regards,
TCIII ArduRover2 Developer