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Trying to understand communication protocols AC-RC-dev

goixiz

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New to Dji drones - i have a spark and a M1P
Its obvious the AC and DC has a wireless communication - I Like to know
1. Can this AC-RC communication be altered or its fixed by Dji internally and controlled, what protocol do they use and how come it can go over 2km?. What if multiple drones fly in the same area?
2. on the dev (phone or tablet) there is an icon and shows "auto" "custom" - image transmission by selecting the auto or custom channel what am i really changing ??

Thanks for any info
 
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Dronason

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Hi

1) Spark use standard wifi, MP use Occusync (DJI system). Both are fixed and you have no choice for other protocols, only some parameters can be manually adjusted. Their protocol is made using the maximum power allowed and improved antennas to maximize the distance of transmission with an acceptable signal quality.
There is for sure a limit on the number of drone at same location. It depend on the number of channels available and local disturbance. Occusync has also the ability to work on more than 1 device (2 RC, goggles and RCs).

2) It allow you to select manually the channel used, in case of MP also the bandwidth. This is useful to bypass the automatic selection if it don't do a good job. It depend on situation, kind of disturbance... At base auto is better as in case of disturbance on the used channel, it will switch to another one. If the automatic selection don't work well then the manual mode can force what to use but then in case the disturbance change, you will have also to manually do the correction.
 

goixiz

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Hi
2) It allow you to select manually the channel used, in case of MP also the bandwidth. This is useful to bypass the automatic selection if it don't do a good job. It depend on situation, kind of disturbance... At base auto is better as in case of disturbance on the used channel, it will switch to another one. If the automatic selection don't work well then the manual mode can force what to use but then in case the disturbance change, you will have also to manually do the correction.

Thanks for clarification
What if i u se OTG ?? the wifi selection on the device has no options other than custom/auto if i remove my otg cable does that mean the selection i perform / change is only for connection protocol between the RC and my Dev (does it change my communication between AC-RC)??
 

Dronason

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Thanks for clarification
What if i u se OTG ?? the wifi selection on the device has no options other than custom/auto if i remove my otg cable does that mean the selection i perform / change is only for connection protocol between the RC and my Dev (does it change my communication between AC-RC)??
Assuming a Spark, with OTG and android device the channel is corresponding to the channel between AC-RC.
There has been many cases between IOS and android regarding OTG as per firmware history.
Without OTG, it is also the channel AC-RC that can be selected. The channel for RC-Device cannot be set at all. The band (2.4/5.8G) is selected as the other than the one used for AC-RC at power up. The channel is decided by DJI and is not always the best choice.
 

FlyGuy8675309

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The Occusync system on the Mavic is quite amazing when you think about it. The control signals are one thing, but being able to stream live HQ video from 3-4 miles? That's just crazy.