FPV antenna tracking under 100$ (Old thread, plan on making a new one)

Pigfarm1403

Builder
So for the last year I have been very interested in long range fpv and I am looking into making a ground-station. Previously I have been using a 1.2ghz system that you can pick up on ebay for about 60$, I'll have a link somewhere in here. I plan on using a 1.2ghz system again and there are two thing that I want to have 1.) An FPV box, like the one Peter made a couple years ago (link somewhere in here) 2.) antenna tracking. I know I can do the FPV box but this is the part that is throwing me off. I would like the antenna tracking setup to be under 150$ (Excluding receivers, antennas, batteries, and hardware) I have seen some people make a 50$ 5.8ghz antenna tracker with a diversity receiver but I want to use a 1.2ghz frequency. I have seen some things like the EZ antenna tracker and the Eagle-tree Eagle-eyes systems but they are both way over my budget. The eagle-eyes system is 100$ but I think you need the 250$ Eagle-tree VECTOR to have antenna tracking. So here is the quest summed up...

Goal: 1.2ghz antenna tracker under 150$

Problem: cost too much to buy stock and no DIY solutions for 1.2ghz

Solution A: Make a diy antenna tracker for 1.2ghz
Solution B: Find A way to use the eagle-tree eagle-eyes ground station without the flight VECTOR

aNTENNA TRACKER.jpg

This is sort of the end goal for me. I can make the station that the electronics lay on and I already have the receivers and antennas, I just need some help making an affordable electronics setup. Any sort of input would be appreciated.

FPV box: https://www.youtube.com/watch?v=uHTClCwcNJA

Current setup: https://www.ebay.com/itm/1-2GHz-150...253589&hash=item58f7b7ccc9:g:-T8AAOSwDiBZMUfg
 
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PsyBorg

Wake up! Time to fly!
Raspberry Pi or something similar set up to read RSSI and to control the servo motors to steer the unit. Pretty simple actually. Could probably go all basic with a simple 3 or 4 stage comparator circuit and some stepper motors with drivers..
 

FoamyDM

Building Fool-Flying Noob
Moderator
Raspberry Pi or something similar set up to read RSSI and to control the servo motors to steer the unit. Pretty simple actually. Could probably go all basic with a simple 3 or 4 stage comparator circuit and some stepper motors with drivers..

Kinda like Bruce's diversity board but with controls to a servo instead?
 

PsyBorg

Wake up! Time to fly!
Not familiar with his set up. Was just a quick and simplistic thought on a possible way to make your own.
 

Pigfarm1403

Builder
Also could I just straight up connect the Gnd, Power, and RSSI connections from the receiver to the arduino board, or do I need something to read those values first.
 

ElectriSean

Eternal Student
Mentor
Also could I just straight up connect the Gnd, Power, and RSSI connections from the receiver to the arduino board, or do I need something to read those values first.

Use a volt meter and measure the RSSI signal to ground at maximum signal strength. If the voltage exceeds 5V you'll need a voltage divider or you'll kill the Arduino
 

Pigfarm1403

Builder
Use a volt meter and measure the RSSI signal to ground at maximum signal strength. If the voltage exceeds 5V you'll need a voltage divider or you'll kill the Arduino

Would a dc voltage sensor work? If so would I just connect the rssi and gnd to the voltage meter?
 
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Pigfarm1403

Builder
So would the best way would be to have the rssi and gnd from the receiver connect to a voltage divider and then have that voltage divider connect to the analog ports of an arduino board. Should I have a two or three receiver setup? I was consider having two yagi directional antennas angled a little apart from each other and have the servo center the two antennas on the plane with the antennas a little bit off of where the plan is. But would it be better to have that same setup but have two patch antennas faced a little apart and a yagi directional antenna in the center pointed right at the plane? BTW thanks for all the help I really appreciate it.
 
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ElectriSean

Eternal Student
Mentor
I thought the point of antenna tracking was so you could get by with a single directional antenna. Having more than one Rx will require you to handle the signal switching as well unless the Rx has diversity built in. I haven't looked at any 1.2g gear, I haven't had a need to go long range so far.
 

PsyBorg

Wake up! Time to fly!
So would the best way would be to have the rssi and gnd from the receiver connect to a voltage divider and then have that voltage divider connect to the analog ports of an arduino board. Should I have a two or three receiver setup? I was consider having two yagi directional antennas angled a little apart from each other and have the servo center the two antennas on the plane with the antennas a little bit off of where the plan is. But would it be better to have that same setup but have two patch antennas faced a little apart and a yagi directional antenna in the center pointed right at the plane? BTW thanks for all the help I really appreciate it.

If I were doing this and was going to do a multi antenna set up I would separate the antennas both laterally and vertically then sync the drive motors to make them move in tandem so when they switch they are not getting slammed around and stressing the mechanical parts of it. Like use on servo for both for left and right tracking while each has its own servo for the tilt axis. That way each antenna has a slightly different view making the diversity of it actually serve a purpose and not be just a redundant back up.
 

Pigfarm1403

Builder
Is it possible to lose signal and still get an rssi reading at the same time? Also my main issue is how do I connect the reciever to the analog ports of an arduino. The antenna stuff I can figure out but I have little to no knowledge on how to connect the receiver to the analog ports of an arduino.
 

ElectriSean

Eternal Student
Mentor
It's definitely possible to have an RSSI reading and not have a usable signal. Does your receiver have an RSSI output that you can measure? If so, measure it at full RSSI. If that voltage reading is over 5V you'll need to connect it through a voltage divider as I mentioned above.

Do you have experience with Arduino?
 

Pigfarm1403

Builder
Yes and Yes, there is a two wire output so I can read the RSSI rating and I do have programming experience but I am a little new to arduino. My real question is how do I connect the receiver to the arduino board. BTW thankyou so much you have been really helpful.
 

ElectriSean

Eternal Student
Mentor
You would connect the RSSI output to an analog pin on the Arduino, and ground to ground of course.. In the code you will read from that pin to do your magic. Did you ever measure the RSSI output voltage? You will need to know the max reading and the lowest reading it still has a usable signal to do your scaling etc. There tons of tutorials on Arduino and analog signals on YouTube.