Replies to This Discussion

Permalink Reply by Dave on April 14, 2012 at 4:14pm

You might want to make this simple mod to your APM board:

http://diydrones.com/profiles/blogs/simple-apm-2560-power-hack

This also powers the RC receiver from the USB, so you won't need to connect the LiPo for radio tests.

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Permalink Reply by FPVRecon on April 14, 2012 at 4:24pm

Thanks Dave, I will take a look at that. 

I guess I could also plug in the receiver with a separate battery pack, to power that. I was thinking there might be some kind of common ground required for that, provided by the lipo power. But I'll give it a try.

Thanks!

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Permalink Reply by FPVRecon on April 14, 2012 at 9:10pm

This does not work. The APM and receiver need a common ground.

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Permalink Reply by James Y. on April 14, 2012 at 4:30pm

The other thing you could do is pull the ESC connections and then plug in a _spare_ ESC which does not have a motor attached to the outputs.  That way you won't hear it complaining, since the beeping is generated by the connected motor.

Running it straight off the USB may pose problems depending on the current draw of your receiver.  But a spare ESC should provide a quick and easy source of +5V.

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Permalink Reply by Dave on April 14, 2012 at 10:46pm

I've measured 20mA current drain for a Turnigy 9-channel receiver, which I'd imagine that would be typical for most receivers.  That shouldn't be an issue for USB.

On my quad,  with APM (1.4 with compass), telemetry, receiver and sonar, I've done the mod and it powers up from a Netbook, Notebook and Desktop without problems.

However, if you're trying to drive servos (say Pan/Tilt), that would cause a problem for the USB supply.

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