I'm thrilled to report that my radio kit arrived and it works well.  Andreas is likewise happy with his kit.

Writeup here:

http://eastbay-rc.blogspot.com/2012/04/review-3dr-900mhz-radio.html

Fixing the air unit network id:

http://eastbay-rc.blogspot.com/2012/04/setting-network-address-on-3...

Thanks 3DR, Tridge, and everybody else that worked in producing this unit!

Views: 2977

Tags: 3dr-radio


Developer
Comment by Andrew Tridgell on April 26, 2012 at 8:48pm

@Dennis,

The only way to tell is to look at the EEPROM settings for the frequency. You can do that in mission planner, or using a terminal program with ATI5.

Cheers, Tridge


Developer
Comment by Andrew Tridgell on April 26, 2012 at 9:11pm

@John,

The log actually shows 5% packet loss. The problem is that the mission planner is mis-reporting the packet loss when using the 3DR radios. That happens because the radios inject MAVLink packets into the stream with a different component ID then the aircraft. The planner doesn't know that, and thinks the packets are from the plane, so when it looks at the sequence numbers it thinks there has been lots of packet loss.

I'll talk to Michael about fixing this.

Cheers, Tridge

Comment by Nicolas Larsen on April 27, 2012 at 5:07am

My 433mhz arrived a midweek. Works like a charm - minimal configuration, well implemented into mission controller and solid range. I tested it between a friends and my own house, connecting it well over 1km away with very rough terrain, several heavy tree lines and a forest between. Certainly no Line of sight here. Gave just over 20% reception with stock antenna at 20db. Great work 3DR!

Comment by Nicolas Larsen on April 27, 2012 at 5:12am

*That was with dual 433mhz "air modules"

Comment by John Moore on April 27, 2012 at 7:37pm

@ Andrew

Thanks for looking at the logs. I never lost telemetry but I was a little worried about the link %'s. I used the Excel method Michael mentioned and charted the signal and noise and I consistently has more noise on the ground than in the air so Ill try adjusting that setup first.

Comment by Dennis on April 27, 2012 at 8:04pm

@ Andrew Tridgell, Thanks for the clarification. I was trying to avoid getting the wrong antenna on the module then powering it up.

 

Alls ok though, I got the frequencies sorted and should maiden tomorrow.

 

All 4 radio's work as described, on the ground, and it looks like other than the three digit ID#, the default settings are spot on.

 

Thanks to all involved in this very usefull, and FUN project.

Dennis


Developer
Comment by Andrew Tridgell on April 27, 2012 at 11:14pm

@John,

I checked with Michael, and he does take into account the sequence numbers of the RADIO packets, so that wasn't the explanation. The 5% loss is from the whole flight, and at times the loss is much higher which is a bit unexpected.

One thing I noticed is the HWSTATUS.Vcc voltage drops quite low at some points in the flight. How are your powering your APM?

Cheers, Tridge

Comment by John Moore on April 28, 2012 at 7:21am

@Andrew

Im powering from a 3S LiPo through the ESC


Developer
Comment by Andrew Tridgell on April 29, 2012 at 6:34pm

@John,

I wonder if your ESC isn't quite handling the load? This is a graph of the 2560 CPU voltage for your flight:

as you can see, it drops below 4V for a while. That could cause quite a few problems. It really should be close to 5V the whole time.

Cheers, Tridge

Comment by John Moore on May 1, 2012 at 9:49am
@Anderew Hmm, thanks for pointing that out. I hadn't noticed any problems but it looks like I should upgrade my ESC / BEC.

I tried another distance run this passed weekend trying to get to about a mile. The signal got pretty low at around 1500m but I didn't lose the connection. I was able to reduce the ground side noise by mounting my antenna on a tripod instead of the side of my truck bed which is where I had it before. I can post the tlog if you'd like to take a look. I was a little surprised that my 5.8 ghz video didn't degrade at that distance but telemetry did. Video is 600mw with the blue beam antenna set.

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