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ModeratorPermalink Reply by Mike Pursifull on February 11, 2012 at 1:05pm

It takes a bit of work, but look over these for similar work/examples - 

http://diydrones.com/profiles/blogs/dx6i-interception-board-rfm22

http://diydrones.com/profiles/blogs/spektrum-dx6i

http://diydrones.com/forum/topics/telemetry-openlrs-and-apm

http://diydrones.com/profiles/blogs/openlrs-firmware1-10-with-trans...

There are others, one I wanted to give you that is most like what you are asking, but I could not locate it. A blog from another member who snooped on the mavlink with an arduino mini pro and slipped only the battery data over a similar TX/RX telemetry link, then displayed on the TX. Perhaps you can locate it where I have failed. Then you will have, not three projects as instruction, but rather three authors who have walked in your shoes before you with the same goal, but with different gear.

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ModeratorPermalink Reply by Mike Pursifull on February 11, 2012 at 1:16pm

See also:

http://diydrones.com/profiles/blogs/ardupilot-mega-telemetry-on-rc

---> http://diydrones.com/forum/topics/telemetry-on-aurora9-transmitter <--- (one of the blogs projects I was most thinking of, be sure to read this one, if any, at the very least)

http://diydrones.com/profiles/blogs/long-range-rc-control-and

http://diydrones.com/profiles/blogs/rfm22-telemetry-link-ms5706

Cheers!

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ModeratorPermalink Reply by Mike Pursifull on February 11, 2012 at 1:27pm

Oh, and http://code.google.com/p/er9x/ - Its not your TX, but it is perhaps the most mature that I've seen and  if you want it now and easiest ... 

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Permalink Reply by Jason Tinacci on February 11, 2012 at 11:25pm

Wow Mike! Thank you so much for all this great info. I've started reading through a few posts and my head is spinning a bit. Still tackling the learning curve and it seems that trying to implement this may be past my current abilities.

Basically, I just want to know what my LiPo voltage is at so I don't over discharge.

On a related note... when I have Xbee connected to my computer the battery voltage reads oddly in APM planner. What should it look like? Here's a screenshot of mine  when connected to a freshly charged LiPo:

Thanks again for all the info you compiled!

Jason

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ModeratorPermalink Reply by Mike Pursifull on February 11, 2012 at 11:53pm

The values will vary depending mainly on the number of cells in your lipo, and also based on how you configure the battery monitor features in APM. Review the wiki instructions http://code.google.com/p/arducopter/wiki/AC2_Current carefully.

I haven't run it without for a while, but without anything configured/attached it used to show around 10.6v, and for a 3S battery, when properly configured, would generally show between 9 and 11 volts (system, under load, pulls down the voltage from the fully charged 12.6.) Be sure to read up on lipo management, and don't let your batteries go below their rated per-cell limits, if possible. Also read up on your ESCs... some ESCs have a low voltage cut out (some offer hard vs soft cutout, too) When the voltage drops below a configurable limit, the ESC either cuts off (very bad for a quad) or pulses.

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ModeratorPermalink Reply by Mike Pursifull on February 11, 2012 at 11:54pm

If you tell it how much capacity, it may keep the percentage updated, but it is a mathematical estimate based on usage. Or you can get a sensor that actually monitors usage. Details are in the wiki. 

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Permalink Reply by Jason Tinacci on February 22, 2012 at 5:22pm

Mike,

Thank you for all your input and replies. They were extremely helpful. For the sake of those that may read these cave drawings in the future, thought I would let you know what my solution to my telemetry issue was. 

Basically, I now have two telemetry units on my quadcopter - the xbee is configured to send down some of the basic info to my laptop in the field and record logs. As my knowledge increases I'd like to be able to push waypoints while in the air but I'm not at that level yet. 

The second telemetry unit I'm using is the TM1000 that came with my Spektrum DX8. I made an adapter that has a voltage lead that connects the TM1000 to the LiPo output and sends the battery voltage to my tx. Now I have real-time numbers right in my hands.

Thanks again for all your help.

Best,

Jason 

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