Pixhawk power issues, new build

Hi all,

I have recently decided to build myself a quadcopter and after lots of reading I went for a pixhawk board (I think it's a clone though as it was ordered from goodlucksell on ebay).

I started by just connecting the pixhawk to the PC via USB and everythign went fine, I was able to flash the board and do all calibration etc.

I then got to the point in the build where I was ready to connect up the ESC etc. I've wired everything up using a 4in1 AGM ESC, The ESC is connected to the pixhawk via one BEC wire and 3 signal only wires. I then have a 9 channel reciever connected via a PWM encoder board with the reciever being powered by the pixhawk.

With this configuration I am not getting any power to the pixhawk when the battery is connected. If I connect via the USB only it powers up fine, if I then plug in the battery the pixhawk powers off.

I have measured the voltage coming out of the power module and it is just over 8 volts on a 3 cell battery. I assume this is one of my problems. Surely the point of this module is to provide 5v?

Anyway, I have now disconnected the power module and plugged my battery directly into the ESC. The pixhawk powers on this way but the ESC's do not always play their tune. Even when they do, I press the safety switch which goes solid blue, I hold the transmitter stick to the right which arms the copter and plays a long note. But I can't get the motors to spin up.

If I connect the esc channel at a time directly into the reciever then the motors all work fine individually.

My thought is that maybe, because the pixhawk is being powered off the ESC as well as reciever being powered off it too, maybe the ESC's arent working properly.

I have tried the motor test in mission planner, and it plays a long note, then two shorts notes but the motors do not move.

Can anyway point me in the right direction to try and troubleshoot this as I am running out of options.

My first thought is I think I have a faulty power module, so I am working on getting that replaced. But should I be able to power up my motors still without this?

Thanks for any help, it will be greatly appreciated.

Matt. 

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –

Replies

  • Just to keep this up to date in case someone has the same issues.

    My power module is outputting just under 9volts!! So looks like a faulty power module is the cause of the issue with the pixhawk turning off. New power module ordered.

    The ESC I purchased is a rebranded Emax 4in1 ESC. Confirmed not working with the pixhawk!!! Have now ordered a 4in1 QBrain ESC to replace it.
    • FWIW, I think the max voltage you can supply to the Pixhawk is around 5.8v?  You may need to install a separate BEC that supplies 5v to get reliable power to the Pixhawk.  I know the usual recommendation with ESC's on multirotors is to get something that doesn't supply power through the control cables (these are usually known as OPTO ESC's).

      In any case, good luck with your build!

      -Erik

  • Ok, After a night of experimenting I have discovered it is something to do with the ESC.

    I plugged in a single ESC I had with a ducted fan attached and that worked fine.

    The ESC I have is this one: http://www.ebay.co.uk/itm/131269465009?_trksid=p2059210.m2749.l2649...

    When I plug a battery into it with it connected to the pixhawk I don't get any of the startup sounds. But if I plug it directly into the reciever then the ESC works fine.

    Is there a setting I need to change somewhere to get the pixhawk to initialise this ESC?

    Thanks, Matt.

This reply was deleted.

Activity