Ground station - FPV / GPS / RSSI Antenna tracker build

[rcwingman]

This is a build log to share the steps and knowlage by making a GPS / RSSI based antenna tracker with open source and open hardware stuff.
Maybe some peoples are interested in building something similar. For a selfish reason I hope this thread can help me to stay motivated and finish this FPV tracker.


Hello my name is Marco and I am from Germany.

I decided to buy a Ultimaker 2 3D printer early this year to improve possibilitys on electronic- and RC builds.
The first projects was some replacement parts and adapters from Thingiverse.
The printer was still on the first filament spool that came with the Printer bundle but it was time to print something bigger.
So the Ghetto-Station-Antanna-Tracker seemed to be a very quick and easy first bigger print for me.
http://www.thingiverse.com/thing:547358

This is a Video of the same station with a other housing:

It consists of 25 to 30 3D-printed parts, 2 servos, a Arduino Mega, Minim OSD, a 2004 display as well as some connectors and buttons.
All in all about 10 parts connected to each other can't be to difficult - I thought.

• Its a remix from Idefix RC with a lot of space for additional stuff.
• The Firmware is already written from Kipk and open source (of cause

Features:

GhettoStation:

• Antenna Tracker:
  Handles different types of pan/tilt configuration:
  • 360° Pan | 90° Tilt
  • 180° Pan | 180° Tilt
  • any other custom configuration
• Easy configuration trough LCD menu
• 4 bank of settings to handle different kind of antenna mounts, or telemetry/baudrate settings.
• Handle protocols from most opensource flightcontrollers:
  • UAVTalk: OpenPilot; Taulabs
  • MAVLink: Arducopter, Arduplane, PixHawk, Autoquad
  • MSP: Multiwii, Baseflight
  • NMEA: GPS NMEA ASCII protocol
  • UBLOX: GPS UBLOX binary protocol
• Internal Protocol optimized for really low baudrate links ( works well with 1200 bauds ) LightTelemetry (LTM) send enough data for a full ground osd or gcs software.
  Supported in Taulabs & Baseflight fork from my github repo:
  • Taulabs : ltmenabled branch activate ltm modules by default for all boards. LTM is also merged in official Taulabs tree. You need to enable it for your board before compiling.
  • Baseflight (naze32) : use LTelemetry branch
  • Compiled binaries : Taulabs & Baseflight builds with LTM enabled
• Convert & output LightTelemetry data for ground OSD ( GhettOSD )
• Support Arduino Mega 1280/2560 or Teensy++2 boards ( Teensy++2 only have one serial,so softserial is used for osd output. Mega already have many hardware uart available => better )
• Battery voltage display & low voltage buzzer alarm

GhettOSD:

• Ground based On Screen Display for GhettoStation (Based on Minimosd-extra software.)
• can displays: Ground Speed / Airspeed / Altitude / Altitude relative to home / Home distance / Total distance / Home direction / Ground course / Voltage / Current / Consumed Current / Flight Time / Flight Modes / GPS sats / GPS fix / Warnings / Pitch / Roll / Heading
• Windows configurator to edit osd settings/panels
  Wire Minimosd Rx to Ghettostation output port, and do not care of mounting an osd on all your r/c stuff anymore.

GhettoProxy:

• 
  This software for Arduino mini converts UAVTalk/MavLink/MSP/NMEA/UBLOX/MTK protocols to LTM. Should be used on your UAV to send LTM over low baudrate telemetry link ( Audio modem / OpenLRSng / RF modules )

FSK-Modem:






After everything was printed and tested it turned out, that my tracker has issues or needs improvements like:

• The 360 degree rotation spins endless.
• The wiring connections between the bottom and moveing upper part gets mechanicaly fatigue. ( cables break)
• Internal components can't be switched or resetet internaly.
• on fast movements the Arduino and OSD kicks out.
• The internal components should be clean implemented to avoid short outs on transportations.
• The Display is too smal, a 12864 can provide interesting Telemetry information like distance, GPS-coordinates, battery, state, RSSI strengh.
• A voice feedback would be great.
• switch between different powersources.
• internal chargeing.
• onboard snowflake display .
• Ground temperature, wind, humidity readings with SHT21, DS18B20 and Ultrasonic sensors.
• Bluetooth connection to a laptop to catch telemetry out.
• RSSI Antenna switching.
• 3DR Modem and FSK Modem switching.
• Lipo fuel gauge implementation to get a better battery state.
• Adding a V-Mount plate on the back to get a stable, protected powersource .

The estimated two week project already takes over 2 months, but It seamed to be 80% done.
I am at this state of the old V1 now:




It's like a curse, after I improve or fixed some issues some minor or new issues appear.
It stated to be a love hate relationship after a while.
The time I spend on this thing is not wrote the value i get out of this. But on this point it would be stupid to stop.

So guys: What do you think & what would you improve?
Goal is to make a ground station out of it

 

[Andre]

Very interesting.

Does it track nicely?

 

[rcwingman]

Hello Andre,

yes V1 worked, in some way. It's not realy safe for long range flights.

Its not a design flaw from Kipk or IdefixRC. Its my fault.
I tought I am so clever to went on a 1S battery setup with a boost converter insted of a simple voltage regulator.
1S can be lazy charged by a USB cable.
The idea was to charge it with an I-Phone adapter
This was a big mistake.
I had a lot of electrical noise. Thats why it was not ready for flight.
After 10-30 minutes the MCU crashed which will always end in a blackout on my FPV-Googles.
So I did not use V1 for any flights.
Its only tested with a FPV-Rover.
Thats the reason for the lack of video footage.

Currently a redesign is on the build.
It's V2 the "Ghetto base station".



critique is very welcome...

 

[Andre]

Would diversity help?

 

[rcwingman]

Good idea,

Diversity was already implemented in V1 and quad diversity is build in V2.
Two in the station and two in my new skyzone glases.

The main problem (bad powersource) of V1 is fixed and V2 will work without any issues (I hope)....


Its a v-mount battery adapter with a Endura 10shd, 4s, 6000mAh lithium cell.
This will last for 30-40 hours. (for RC-zeppelins?

• No danger for popped cells because it has a protection board on it.
• Fast battery change.
• buildin capacity indicator.

Maybe you know this types of batterys from your film production company?

This batteries are expencive. A new unbranded costs about 130 Euro.
...BUT you can get them with dead cells for 10-20 Euro each on Ebay.
Just replace (usualy 1-3) the bad 18650 cells and its good again.
Maybe they are good for other RC-Projects too.

 

[SmilingDevil]

love your Build and admire your skill, I never touched those arduino things... my programing skills suck..

Good luck! I'll stick around

 

[Andre]

Hah those type of batteries make my shoulder hurt

But good idea.

And now I see the diversity receiver setup.

How are you running video from the GS to your goggles?

 

[rcwingman]

Thanks SmilingDevil.

@ Andre

You can switch that as you wish.
I added a extra switching box to give it the maximum flexibility.
You can download it here:
http://www.thingiverse.com/thing:1359733

There is a self charging 2S backup battery setup in the case.
2x 18650 cells 3000mAh with mini lithium charging board.
If something goes wrong with the Main powersource,
it (should) automaticly switch to backup power which lasts about 6-8 hours.





Next task is to get all telemetry funktions on the screen.
Its a little bit challenging to make a nice userfriendly flexible dashboard.
Every menue item should be switchable with 2-3 button clicks.
Otherwise its not quick enough in case of emergency.

 

[Andre]

I wonder if a RPi could do the job.
Of course that means more code and more interface work as well.

 

[rcwingman]

glad you ask that.

yes it can. Its not hard too do this.
The main problem is the complexity and speed of a RPi.

• It takes 30-100 seconds until its up. what bores me
• The touchscreens are not good to see in bright sunlight.
• They need more energy
• They produce more heat
• You have to translate the code for Raspberry pi.

In my eyes a RPi for a main system is too much for that little task the tracker has to do.
Or make a processing program that communicates for arduino.
Imagine. You can fly to the moon with a fraction of that processing power!

Better use a cheep chinese 30 Dollar Android tablet
and hook it to the groundstation to get colorful instrument readings out of the telemetry.
Check if the screen is good readable outside before you buy one.
Hack the software and make it as light as possible to keep it fast could be a good idea.

Ive playing with the idea for some years on my Windows based 9X Radio.
I want to use it with OPENROV to explore the Staffelsee in Germany.

 

[Andre]

Ok that is a whole new level of awesome.

 

[rcwingman]

realy? Yeah i installed Microsoft combat flight simulator on it to train my fpv flying skills... but its not done too... like a lot of other things

 

[rcwingman]

Some update and progress.

Today I am trying to finish the wireing of that KS108 Display and 7 way rotary encoder.
I had some problems to get the PLA-coverplate cleaned up and tryed the wet sand trick.
It turnded out successfull to use 5 minutes epoxi to fill the tiny gaps after the sanding on the PLA print.
The finising process on PLA was:

• Sanding with 100 sandpaper
• Sanding with 300 sandpaper
• Wash and dry it with water
• Use very thin epoxy coating
• Sand it again
• Wash and dry it wit water again
• Spray it with several layers of paint

If there are still inperfections just repeat again and again.

I am currently strugling with the wireing. There must be about several hundred connections to make and measure.
Hoping to be done this evening. ( its afternoon)

 

[rcwingman]

I just found one of this buttons in my spare part box.

Its a display - switch.
With other words: A switch with a integrated display.

Any ideas how this could be a usefull implementation into the Ground station?
http://www.nkkswitches.com/SmartSwitch-ProgrammableSwitches/

 

[rcwingman]

More changes from the original design.

• KS108 Display implementation is done.. (its bigger and has 128x64pixels)
• Faceplate redesign was successfull too except the right part.
  I added some carbon fiber to make it look more cool.
• 7 Way rotary encoder attached and tested (the black wheel left on the display)
• Dashboardbutton wired and tested ( the red one)
• Switchable backlight ( because the backlight sucks 200mAh current)

I think i will use it for the PSK-Modem or VRX diversity indication.

Next step is to attach FPV video display on the right side....








200mAh for the backlight of the KS108 Display is a lot.

 

[rcwingman]

Update...
If somebody is interested in my 3D printed modifications, it would be a pleasure to share them on Thingiverse.

It turns out that this Ghetto-Base-Station will become a never ending project.

In the past week a new enclosure was printed.
It will give additional space for a new Raspberry Pi 3, Segementdisplays and a DVR...

The Raspberry 3 is for Missionplaner, UAV Telemetry Animations and data loggings.
It will share the AV-Display with the VRX and DVR.

The segment displays are specialy for the VRX to have a better view on the channel and signal strength.
The DVR is not specialy made for FPV Flying. But the features of that 30 Euro device are fantastic.
Here is a picture of it.

 

[rockyboy]

You're in the right forum - "Mad Scratch Builders"!!

That's a seriously impressive project!

Great work!

 

[rcwingman]

Thank you rockyboy.
Great to get some feedback.

What would you change on this groundstation?
Are you missing any important features?
Or are there to many features?
Whats bad on this machine?

 

[smithhayward]

That's quite an expensive OLED Switch you had in your SPARE parts box. I found it (or similar ranging from US$77-116). Crazy awesome though...

This is quite a build, very impressed. Not sure I will ever have a need for it, but even just seeing the basic design I can imagine maybe 3D printing an RC Nerf surface-to-air missile installation...

 

[rcwingman]

Brilliant Idea.
I was playing with the idea to buy some broken Softair guns and add a RSSI-Based anti air cannon on a second turret.
So the Ghettostation acts like a "RADAR"... you know what i mean? Just as a fun feature. (after everything is done, what will never happen)

Well this switches are on sale now for 16 Euro.
http://www.ebay.de/itm/311554483385?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT
So its still expensive but "cheep" for a Display switch... you know
The programming is a little bit tricky....
If you are interested in Buying one I can "route" one switch via DHL for 6,20 Euro shipping back in the US, where it was born