Make your own Diversity Video Receiver

[teslahed]

My next mini project will be a diversity receiver unit.

I am following Bruce';s build instructions, full credit for the original design goes to Bruce at RCModelReview - thanks Bruce!

I have modified the layout to build it on pad board rather than dead bug style.

http://youtu.be/4yDfRrsH0WM

http://youtu.be/0zSdIBBydz0

With components sources from here;

http://www.bitsbox.co.uk/

More details to follow...

[Jimbodiddly]

Will watch this with interest.

[teslahed]

Just started the basic layout;

[teslahed]

It took me a few attempts, mostly due to my determination to build my diversity receiver on veroboard rather than using Bruce';s ';dead bug'; style. I could have built it dead bug style then filled the thing with epoxy to stop it short circuiting but i prefer the neatness of a ';proper'; circuit and it makes it easier to change things in the future if necessary;






It did take me 3 attempts to get the layout right - but i got there in the end

[teslahed]

Well my fpv diversity receiver is now tested as working. But one of my two RC305 receivers is dodgy so i wont be using it until a replacement arrives from hobbyking in a week or two.

I was able to connect the single working video receiver up to one video input and then observe the diversity circuit switch to that channel when i also connect up the RSSI signal to the right RSSI input pin. Then if i swap the video signal to the other video input pin i lose my picture as the video input and RSSI input are both plugged into opposite sides of the circuit. Then if i also swap the RSSI signal to the correct RSSI input pin the opposite LED lights up and i get a video signal passed through again.

This is the best i can do to test with only 1 working video receiver. I can only hope that when i have two it will switch between them both in the right way.

I went for the delux option on the video receivers and ordered myself two of these;



So i';ll have a full 32 channel diversity receiver when it';s all working and done  ::)

[powerlord]

Nice :-)

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[teslahed]

Another video from Bruce;

http://youtu.be/MVz4Woo0KaM

[Col_M]

Bruce';s videos are really good and this simple diversity project is great!

However I';m looking forward to his other open source diversity controller that';s less simple which he has mentioned a few times.
I';d be up for doing a "group buy" from a PCB manufactuer when he releases the plans, usually the more you get the cheaper they are so I could order a few (20-30) and sell on the others at cost, it';s open source after all 

[teslahed]

I will also be interested in the more involved diversity receiver project and if you end up ordering enough bits to make a few give me a shout please - I';ll likely want to grab some off you if possible, thanks.

Personally i think bruce';s videos are great and very informative, even if i do occasionally feel like I';m back at school when watching them. He obviously puts a lot of time and effort into them and I hope he keeps making more

[teslahed]

Well it';s all tested as working.

Except I';ve managed to blow one of my two receiver units:cry. I';m pretty sure i did something stupid with my soldering iron whilst i was trying to get it all working properly. But i';ve tested it all as much as possible using the bits i have and i think i';ll be fine when my replacement RC832 unit turns up.

And of course i will be fitting it all inside a nice box when it';s done.

[teslahed]

I';ve just got a second receiver in the post today so i';ve had a quick test of my diversity receiver;

http://youtu.be/k6rPyjGqBio

It seems to work fine. I';ve just done another test with a helical antenna on one of the two receivers and it does indeed switch to that receiver when i point the helical towards my aircraft and then back to the omni directional when i point the directional the wrong way.

I';m assuming this means it';s all working fine

Next step - get it neatened up and put in a box, then tested properly outdoors.

[HowDoIfly]

Excellent work and thanks for sharing this test, despite it not switching as you';d hoped. That "bias" of the omni stood it';s ground really, really well!

[teslahed]

Second test of the diversity receiver - this time with a helical high gain directional antenna as well as a low gain omni.

http://youtu.be/fBM3V40Ge7c

Seems to do the trick

[teslahed]

[teslahed]

Now with neater wiring and proper plugs!

http://youtu.be/YhgbNtzGrJU

I';m much happier with the way the diversity switcher seems to be switching in this latest test. I think using 2 similar receiver aerials and putting the low pass filter on the 5 volt power supply have helped since previous tests.

[teslahed]

First flight with the new diversity receiver;

http://youtu.be/_2vHpWRpTYQ

[Trev2971]

edge of my seat stuff that was fair play  .... 

[powerlord]

Any chance of doing a detailed instructable. Com on that?  Looks great

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[teslahed]

I';m going to have a go with eagletree on thursday evening to see if i can produce a neater circuit diagram (then neater circuit) and I';ll come back with more info hopefully after then.

Otherwise i just followed Bruce';s method and neatened it up a bit. The circuit is identical, just flipped around onto perf board, the inputs and outputs are the same - i just used a bunch of header pins (which i soldered to to make sure of the connection) to make things a little neater and easier to wire to.

I will rehouse the project into a smaller box soon but it';s just a question of holes for power in, video out and the two aerial connections.

I';m happy to answer any specific questions.

[powerlord]

Ah cool just watched Bruce';s video.  Actually I think I';ll put one together with an arduino mini pro as the comparators and just use the switches.  Since I';ve got them lying about. It also let';s you do more clever stuff say,  like only switch the signal after its stable for a period,  I dunno really... Prob some stuff there.


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[teslahed]

I';ll be interested to hear how you get on with that. I might give it a go myself but my skills with the arduino aren';t good enough to do that by myself i think.

[powerlord]

There';s nowt to it.  Easier than what you';ve done. 

It has analogue inputs show you can measure the rssi directly.

And digital outputs to switch video.

Have a look through a few examples on arduino. Cc and you';ll see its a piece of p1ss

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[teslahed]

It';s the lack of programming experience that will hold me back i think.

In terms of inputs and outputs, as you say;

2 x Analogue inputs for RSSI on the arduino.

2 x digital outputs on the arduino used to switch 4066 switching chip between the two video signals?

1 x 4066 switcher to take the two video signals in from the receivers and 2 digital inputs in from the arduino to output the best video signal to the monitor.

Seems straight forward enough.

If you have a go i might end up copying you / trying myself.

[powerlord]

Yup that';s it.  No advantage really.  But then you are free to code fancier stuff. 

Seriously you';ll see its a few lines of code only,  and the docs have full examples

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[Oakie]

Chris thats some serious ups! the skills are overflowing. some super sling shots!

[guest2350]

I saw this vid of Bruce';s a good while back and I am now thinking of ditching my antenna tracker project and go with a complex diversity system instead. I';m thinking of a 4 way diversity with 3 helicals on a convex surface at 120 degrees apart in order to get a wide directional coverage, considering if I am doing long range fights it will only be in one direction so no need to track behind me. Also a skew planar on the 4th port to get a good radius coverage. I plan to do all this in 2.4ghz with a 5.8ghz repeater to the goggles.
Thanks for sharing your effort TH, hopefully I can order all the bits soon and get cracking!