Have just bitten the bullet and ordered a pixhawk.
I notice in the instructions is says 'APM power module-REQUIRED' and it appears to ship with one.
However I will be using it on my big octa and the 90A rated current of the power module will not be enough.
At the moment I am using a 180A attopilot on an APM2.6 (and its not that accurate) but the pixhawk has fancy connectors for the power module.
Questions.
Is the 90A rating of the APM power module just a sensing limit and might it take way more before frying?
Is the power module really vital or can I power it from the servo rail?
Is there another option.
I am considering just using the APM power thing on half the motors and changing the settings to double the amps.
Replies
Is there any problem with cutting the +5V lines coming out of the PM and instead powering the Pixhawk with a stand-alone higher-current BEC? Then the servo rail could be powered with the built-in BEC the ESC as the backup power. That way we wouldn't be constrained by the 2.25A limit of the PM. In my case I have a 10A BEC and my ESC will supply 5A.
Ive checked the link about connecting an attopilot to the pixhawk but there are still 3 spare wires and I cant find a pixhawk pinout diagram anywhere. I would like to feed in 5v from a ubec and want to make certain what the other wires are for. All searches show PX4 which is not the same.
Also, Marco hinted at a power module MK2. Do we have any more info about that?
Thanks
You can power the Pixhawk directly from the servo rail as long as the voltage is not over... 5V(ish). I'm not sure where the limit is, but if you plug in an ESC outputting 5V, then it will run off of that. It has a 3-way power controller, and it can take power supply from either the PM input plug, servo rail, or USB.
This is actually a nice feature, as you can use the PM *and* ESC, and have redundant power supply! I've actually tested this and it works. Unplug one or the other, and it just keeps going.
http://diydrones.com/forum/topics/alternative-power-modules