Remote activated switch?

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I wish the P3 controller had another channel the user could configure. I would like to be able to remotely turn an electrical switch on & off. For right now I thought it would be nice for my light kit. I know the RCDH landing gear works off the Flight Mode Switch but RCDH will not sell the harness without all the gear hardware. Plus it runs servos and not a direct switch like I want. Has anyone tried anything like this???
 
try this one. but it's one way (meaning, from channel1 to channel2 and to return to channel1 you need to switch power off).
 
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Thanks, I had looked at the RC-10 before. It's not the solution I'm looking for at the moment. If I can't find anything else maybe I'll try it. Wonder how much 6950r is? I'm guessing it's about $100.
 
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As the Phantoms evolve they've become increasingly less modular and more difficult to modify electrically.

The RCDH module is the only thing I've seen to add a channel sort-of-speak.

Buying from a Russian site?
Dubious.
 
This approach requires a bit more caution as you'll have to derive the capabilities of the LED drive circuit.
 
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http://datasheet.seekic.com/PdfFile/PC8/PC817_SHARP_Sharp_Electrionic_Components.pdf

You'd need to take the phantom apart and measure the voltage across the LEDs and then look at the data sheet to check the input side is suitable. What you're trying to switch will dictate if you need this to power a relay or Darlington pair on the output.
But the best i could hope for is to be able to add a 20 ma type relay if i eliminate one of the leds after checking the voltage going to the led and that is the coil voltage. As there is no way to tell how much that circuit could handle. Right?
 
If you apply generic engineering margins the circuit should be designed to sink 1.5-2.0x the nominal drain.

The truth is that this type of approach without data sheets and/or schematic is risky.

I applaud the 'maker' attitude but the Phantom P3 is highly integrated, designed to the minimum, and not the best platform to 'hack' in this manner.
 
But the best i could hope for is to be able to add a 20 ma type relay if i eliminate one of the leds after checking the voltage going to the led and that is the coil voltage. As there is no way to tell how much that circuit could handle. Right?

Not quite, the input to the coupler is basically an LED. The output is a photoresister so you build your own circuit using that as the trigger. Therefore you have complete control of the voltage and current the circuit can supply as you build it. If I want to use the P3's LED's to turn my immersion heater on and off that's entirely possible.
That's the beauty of these devises complete isolation.

That's why I like the optocoupler approach. It's about as unobtrusive as it's possible to get. You are (at a simplistic level) replacing one LED for another.

If you don't want to touch the P3's circuits at all you could build a manual optocoupler. Keep the flight LED's hooked up, put a photoresister next to it and wrap the "lens" in insulating tape to control the environment, then you can build your trigger circuit round the photoresister and have not touched the phantoms electronics in any way.
 
The phantom 3 retractable leg kits simply have you toggle between F and P modes 3 times. You should figure out what circuit that taps into. Also canbus extension port might be useful?
 
try this one. but it's one way (meaning, from channel1 to channel2 and to return to channel1 you need to switch power off).
Wow! That's a high priced option to turn lights on and off. I'm looking for something a little cheaper.
 
option to turn lights on and off.
hehe.. That device manages all power from the battery (40-90A) and not just switches lights :) There are no other remote parachute activation system on market which will turn props off before deploying the parachute. All other systems just move the servo. You may imagine what will happen with parachute when it will be wound on to running props.
So cutting the power from running props is a must before releasing the chute.
 
Well, I had another thought. Why not mount a phototransistor (or even a CdS cell) under the front LED lenses. Use that to trigger whatever you want since the front LEDs are remote trigerable. It would require zero invasive modifications to the drone itself. No tying into unknown wiring. Simply 3D print a clip to snap/tape/etc over the LED lenses on the front arms to block other light. Then you can build your circuit using known data sheets, known components, and not even void your DJI warranty.
 

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