Summary

This is a fpv rssi switch that i designed a couple of years ago. It can switch between 5 receivers.(it is basically a device that takes the video output from the receiver with the best reception, so that you can have multiple directional antennas pointing at different directions etc)

Instructions

This is a OLD project of mine, i am not currently working on it and i don't think i will any more, but i thought it would be nice to put it up here if anyone wants to continue my work. And i have gotten a lot of requests about it. As you can see there is lots of room for improvements... And the documentations and schematics etc, is very poor..

I have been flying with it for a long time now and it have never failed me.. i have only used 2 receivers, but it is capable of up to 5..

here is the old text i wrote about it a long time ago..

FPV RSSI SWITCH

http://www.youtube.com/watch?v=CHuyM7hESNw introduction, early version
http://www.youtube.com/watch?v=E998gxznmkw groundstation
http://www.youtube.com/watch?v=W-yTHnYzI4Q testflight
http://www.youtube.com/watch?v=DKZwEU5sY0A menu, barview

I made myself a Fpv Rssi Switch for when i fly fpv.
It's uses rssi output of video receivers (most can be modded to output rssi) and
switches to the one with the best reception (in a fancy way), up to 5 receivers can be used,,

It is based on Arduino.

There are different video receivers some have rssi volt that is 0v when no reception and 5v when full.
Some have 3v when no reception and goes down tho 0v when full reception. This switch can use these
kinds of receivers together.. A simple comparator wouldn't work here..

This switch takes rssi voltages from 0v to 5v.. if your receiver puts out more, you must lower the
volt to max 5v (with a voltage divider etc)

I have not had time to work on it for a while now, and my hope is that now when i release it to
the world, that it will be useful for someone...

The schematic that comes with this file, is a early draft and not correct..

The pcb i draw by hand, and the version that comes with this file is new, and not tested..
(but should fix a couple of issues with earlier version)
The difference between the new pcb layout and my prototype on the picture, is that the pcb layout now have backlight
controlled by the cpu (make sure to size the display resistors so not cpu port max current is exceeded). Also there is pulldown resistors to the analog rssi inputs on the cpu, on the prototype in the picture they are on the backside,,
(100K ohm or something, try and see what is best)

For the Display i use DogLcd library from http://code.google.com/p/doglcd/wiki/Code

Have a nice day and happy hacking !

FPV RSSI SWITCH, 5-port