I have been looking into the possibility to operate an antenna tracker with the APM software and found that the only options are the ground stations or a laptop + missionPlanner + a servo controller. Because I want to take with me as little as possible and have a system which is housed in one single case I decided therefore to build something on my own.
I ended up using a MinimOSD by modifying their software and connecting additional pins directly on the chip. This way, the tracker worked great. One remaining problem is that the OSD shuts down all the time with "REQUESTING DATA STREAM" although droidPlanner is connected all the times. Which is a bit strange and maybe I have just deleted a bit to much while shrinking the code down to fit in my additions ;-)
The above problem disappears by setingt the "enable_mav_request" variable to 0. Seems that because of the additional code some Mavlink data get dropt since the "enable_mav_request" seems to be triggered by the "waitingMAVBeats" var?
https://www.youtube.com/watch?v=Sqejb8E9oyQ
Features:
- 433/915 or in my case 868 telemetry
- MinimOSD - OSD
- 2x RX5808 modules in a RSSI diversity config.
- Bluetooth link / HC-05
- 5.8GHz TX module to send the video on a different channel to my goggles...
Planed features:
- Switch-mode power supply&filtering, battery monitoring
- Shielding of the analog video parts and of the telemetry module & metal casing
- Automated channel switching (DJI for example lets you change your channels in-flight)
- Serial links (GPS, ADS-B/FLARM receivers etc.)
- Exposed pins/connectors for more internal & external expansions
At the moment the hole ting is very hackt together but I plan to make a custom board to place all the components on it and to fit into some sort of case. A couple max7465 are ordered to test the minimOSD software on a 1284 and a 2560 first, which would allow more functionality since they have more IO`s and additional uart ports.
However, if somebody has more suggestion what should be included or even better would be interested in participating, the project is hosted on github.
Comments
For those who want to search for this and other approaches to having a 'UAS antenna system', a link to this blog post can be found on this page.
Glad to learn that audio link is not the way to go with an APM w/radio link. Many thanks for this, and for putting together a project I'll be likely using in a couple of monthes.
Hi Tom
I think it would be very interesting to add some OSD warning for incoming traffic. Even in non out of sight flights! Last week fe. while I was busy testing some stuff on the ground I parked the plane for a moment above me and totally missed an incoming Cessna which came very close...
Since ADS-B receivers (esp. DIY solutions) are becoming very cheap and the range is so high (50km++) I do not see many reasons not to integrate them in a ground station...
ADS-B however, is only mandatory for planes with 5t+ and for altitudes of more than 5000ft, at least in CH. Most likely far more helpful for low-level fpv flights would be the FLARM system. But since one device is so expensive (flarmMouse costs 600d) it could be an option to plug it into the ground station and just listen for traffic (protected in case of a crash/loss, sharing the data between many planes in a group...).
Or use one the DIY FLARM receiver only system which would be perfectly legal... Shame it is not ready yet...
http://wiki.glidernet.org/ogn-tracker
In a stand-alone system the audio link is useful. But otherwise, since this is diydrones and most people have data links, I agree that snooping on the data link is the way to go.
What do you have planned for ADS-B?
You can use the audio as a link, sure... The MyFlyDream ATT does it like this but you already have a datalink with superior range (lower freq. / digital / noise resistant).
If your high gain directional antenna loses the plane for a short period of time (eg. obstacle, flying directly over the antenna) you lose both your video and the possibility of the tracker to get back on track since there are no audio/gps data as well.
+you have to deal with modulating digital-analog-digital for the audio channel...
sry but I can not see any advantage here...
This is sweat : I'd be interested once I finally reach longer range. I would love not using a laptop.
How hard/possible would it be to get the GPS data through the audio link (still using the ardupilot) ?