Way back in December last year, I put up this post which showed me ground testing 3g Telemetry.
Since then I've been very busy with other projects and only got back around to looking at 3g Telemetry last month.
I bought the new Skywalker X8 platform as the Hugin in the above post just was not strong enough to cope with AP duties.
The X8 is the perfect APM platform, I really can't rate it highly enough. It has mountains of space, can easily carry a 2kg payload and I'm getting flight durations of in excess of 1 hour and 20 minutes with 10Ah of lipo's on board.
I'm a fan of keeping things simple so only having 2 servo's on board increases reliability. About the only down side (which is actually an upside for me) is that it has an insane glide ratio, this makes landings slightly challenging, however it does help achieve the long flight times. Some X8 users have already added parachutes, however I tend to enjoy the challenge of bringing her down incident free.
I've flown around 20 flights now on 3g Telemetry and it works really well, I've had less trouble with it than the usual point to point radios and the range is well.... practically limitless. Not to mention the simplicity of my ground station setup, no antennas and nothing else to cart around other than my laptop and phone.
A lot of people commented in the previous post that I would not get great altitude, my testing has revealed I can go very high (thousands of feet) and still have plenty of signal. My longest flight has been 45km, which tested hand-off between cell towers which is also seamless.
The great thing about the fatbox is that its plug and play, it has built in dynamic DNS so you don't need to know the IP address you are allocated.
Data usage averages around 7mb for a 1 hour flight.
If you are keen on doing this yourself, make sure you join the group "Telemetry over cellular IP" some users are making some great progress on code that allows cheap 3g modules to be plugged directly into the APM.
Also take the time to read my previous post here which covers off the important topic of cellular APN's and how to make sure you get your SIM cards configured correctly to allow a direct non-fire walled connection to the internet.
Comment by Toby Mills on August 9, 2012 at 1:01am
Comment by Elliott Gaskill on August 9, 2012 at 8:18am Have you thought about putting the software up on a free usage tier Amazon AWS Windows 2008 R2 server? aws.amazon.com
Comment by Elliott Gaskill on August 9, 2012 at 12:57pm Using an AWS EC2 server for telemetry would cut down on latency most likely. That way if your mobile hotspot goes wonky or hell even if your laptop dies on you completely your drone will still be receiving orders from the server. You would just be using RDP to remote in to your "Ground Station" server in the cloud with your laptop.
Comment by Toby Mills on August 9, 2012 at 5:56pm I think AWS would have higher latency.
AWS is in the US and I am in NZ. If you use SIM cards from the same carrier, the latency should be fairly low.
Does it matter if the latency was even as high as 1 or 2 seconds anyway?
60ms is no problem.
Comment by Elliott Gaskill on August 10, 2012 at 12:15am hmm, good points.
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