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Re: Bruce' FPV Diversity Controller project

PostPosted: Mon May 21, 2012 6:48 pm
by Rixx
Okay, partial success here. First, I did not use paralelled outputs with floating controls. I used two separate gates, with remaining two gates floating. Now I soldered some jumpers, so there are 2 gates paralell per channel. Picture is much much better than before, but still dark and grainy.

Do you think guys I might just stack more chips? Say, one or two atop existing one? This works with motor drives or transistors arrays :lol: . With every additional chip, RON should decrease by paralelling...

I checked local suppliers and I couldn't get dedicated video switch IC, neither suitable opamp for buffer. I want this working ASAP, so no chinese chips from ebay for me now. As the last resort I could just buy some small relays, if stacking idea won't work :roll:

Re: Bruce' FPV Diversity Controller project

PostPosted: Mon May 21, 2012 8:35 pm
by BillGriffiths100
http://en.wikibooks.org/wiki/Practical_ ... cs/IC/4066
Referring to the above link illustration.
From what I can remember of using this chip if you parallel up the gates and don't use the X's to the X's but use the X to a Y the result is worse than using the single gates they interfere with each other due to internal circuitry conflicts.
I can remember being puzzled by the results when using it for resistor switching in amplifiers until I discovered that little quirk. Since the X's are adjacent to the Y's when bread boarding it seems obvious to just blob a bit of solder to make that connection!
Try just using the gates alone or paralleling using X's to X's Y's to Y's.

Re: Bruce' FPV Diversity Controller project

PostPosted: Mon May 21, 2012 9:21 pm
by Rixx
BillGriffiths100 wrote:Since the X's are adjacent to the Y's when bread boarding it seems obvious to just blob a bit of solder to make that connection!
Try just using the gates alone or paralleling using X's to X's Y's to Y's.


That's exactly what I did! :lol: I switched it now, x to x, y to y. I don't see a difference in picture with first set of gates, but second set seems damaged, picture is very dark. I'll get more those chips to try, along with the relays.

Re: Bruce' FPV Diversity Controller project

PostPosted: Tue May 22, 2012 3:11 am
by RCModelReviews
I'll try to do a video tomorrow showing the difference between "through the switch" and bypassing the switch.

Re: Bruce' FPV Diversity Controller project

PostPosted: Tue May 22, 2012 7:13 am
by Rixx
I got 3 more 4066's to stack, and a 5V signal relay. Stated contact resistance is 100 ohms max, at 6V 1A. I think still lower than my 4066's grandpa. :lol: Relay needs 30mA for coil, I could power this right from arduino (maybe with couple of parallel inputs) plus flyback diode.

Re: Bruce' FPV Diversity Controller project

PostPosted: Tue May 22, 2012 3:31 pm
by Rixx
It took 3 chips stacked, to get usable picture - just a little darker than bypassed. :mrgreen: Original one seems damaged so I cannot try 4-stack... but it is okay now. I might try relay if it would work better, but now I just want to stuff this into a box and go flying. Thanks for help guys.

Re: Bruce' FPV Diversity Controller project

PostPosted: Thu May 24, 2012 3:03 pm
by RONALD MCDONALD
Bruce is there any chance of seeing the schematic and software soon?
Best Wishes
Ron

Re: Bruce' FPV Diversity Controller project

PostPosted: Thu May 24, 2012 5:03 pm
by Rixx
I decided to upgrade my diversity with relay and new stripboard. Much less wiring and nice clear layout. It may eat some more power than IC version, but I have some Pb batteries from UPS to put in use. I run out of shielded cable, so RF modules are connected by simple wires and they seem to pick up SBEC RF noise. Even if they are only few centimeters long (<10), I get some weak diagonal lines on the screen (I did have shielded wires there before and there was no interference). I might swap them with shielded, but for now I can live with that, picture is pretty OK.

Another thing - I consider some kind of cooling there. RF modules and SBEC get pretty warm after some time. Maybe that is inside specs, but I just like my electronics cool to the touch. The box is black so I'll drill some vents there and maybe add a small fan. I might get a thermistor and let arduino switch the fan :shock: . And I thought of some kind of indicator, to show whats going on - like RSSI calibration at startup... I have one-digit alphanumeric segment LED display in parts box that could take all remaining arduino pins. Yes, I'm overthinking it a litte :lol: . But strong wind for another week or so, I have plenty of time to play with this.

Re: Bruce' FPV Diversity Controller project

PostPosted: Thu May 24, 2012 8:57 pm
by rotorz
I'd be more interested to see more information on Rixx dual diversity controller.

I've never yet had anything to do with Arduino, I've got some experience with 'PIC' and 'MSP430' but none at all with arduino.

Sounds like it would make an ideal first Arduino project, any chance of seeing some info Rixx?

Re: Bruce' FPV Diversity Controller project

PostPosted: Thu May 24, 2012 9:55 pm
by Rixx
rotorz wrote:I'd be more interested to see more information on Rixx dual diversity controller.

I've never yet had anything to do with Arduino, I've got some experience with 'PIC' and 'MSP430' but none at all with arduino.

Sounds like it would make an ideal first Arduino project, any chance of seeing some info Rixx?


I did some PIC (asm), and AVR (C) programming in past. But chinese arduino knock-offs are so cheap and offer quite a bit of memory (Atmega328), that it is so much quicker to slap together usable arduino code than do some real programming. I do not like programming, I want projects to go together fast and I don't care about proper, nice, efficient and fast code. Buying arduinos for my projects is just cheaper than spending days troubleshooting and tuning some real code.

I can slap together info and pics for you hopefuly by the end of weekend