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Switching from manual to autopilot - best way?

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Hi,

I'm currently working on my first UAV (a moviestar with PIC processor). Whilst I've decided on most things, I thought I'd try and find out how others are handling the switching from manual to auto.

My current thought is to use a PCM reciever with fail safe for out of range and the gear switch set to switch between the reciever and the autopilot by switching the servos via electronic switches or relays. This should give me auto manually or if the reciever fails.

Any better ideas? Specifics?

Thanks.

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Hi,

I wonder the same thing but I saw a comment about at:

http://home.online.no/~la9ex/GPS%20guiding...s%20guiding.htm

"A pair of IC's to make a electronic switch, trough micro controller or

bypass for manuel control."

I also thought about If you couldn't handled that when you do the programming, for example to read a switch channel then the programming is just looping if you swith on "manual mode" and not doing anything and you use Y-cables for the servo connections.

I haven't tried it but if you do please let me know if its working.

Thanks // Marcus

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I already thought about this for the future. My idea was to use a 2-to-1 multiplexer with enough channels for the number of servos you want to switch. On all "0" inputs you put the signals coming from the receiver, on "1" inputs those given by the autopilot, and the outputs to the servos. Use a PIC to select inputs according to a dedicated R/C channel. Using a fail-safe would be nice to automatically switch to autopilot. You could also implement the fail-safe in the PIC if you don't want to buy a PCM receiver.

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Thats the best answer Ive heard to that problem Kilrah, I think I will make a note of it for future use !

Simple and efective...

Well Done ,Terry

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Yep, not made it yet though. I was planning to use it as a security device to switch between my future system that should handle everything including R/C and a standard RX in case everything goes wrong. So I wanted to add a power supply switch that could at the same time switch power to the servos to a secondary battery that is totally separated from the main supply for increased security. When switching, the servos would then be connected to a completely independent system. That's supposing that the switch has to be absolutely reliable. I've not done more reflexion on thie power part yet, but if I do soon I'll add a post with it.

For autopilot switching it shouldn't be necessary.

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I have implemented both a manual micro switch with a servo and a video switch/multiplexer using a pic. The manual switch was easiest. The pic

required a few weeks of programming and bulding of a pc board, box,

connectors etc. For switching the servo control (the white wire) a CD4066 might work. I used a pic measure the PW from a receiver channel and

digtal out from the same pic to enable 1 of the 4 switches and disable the

other three. I just wired the 4 outputs together for a 1 to 4 multiplexer. If

you are worried about wired or, you could use a ADG333. I was switching video,

but servo control should be ok for either chip.

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