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May 20, 2014, 05:41 PM
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flickycity's Avatar
Quote:
Originally Posted by Mmon77
I know PB has been working on getting Deviation working on the Taranis. If he got it going, and we had the ability to add modules as we do on the Devo series, that would be probably the best tx for the money anywhere. Some might argue it already is, but I prefer Deviation to the er9x/opentx, etc firmware.

I remember reading a post about why you couldn't just add a module to the Taranis in the same way you do to devo. There was something fundamentally different in the processing chain. So the only way to add modules is via the module bay. I don't know what the limitations of the bay is though. E.g can a universal module be made

Quote:
Originally Posted by eaman
I guess I will try with lemons as R620 are not available on HK europe right now, and I don't need more then 3/4ch for a full wing.

HK have the new R615X which looks interesting.

I haven't done the range mod yet or I'd test the R615 for you. (I'll try and do it today)

I bought the R615 for my mini breeze so I hope it's good enough!
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May 20, 2014, 06:22 PM
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Mike Meyer's Avatar
Quote:
Originally Posted by flickycity
I remember reading a post about why you couldn't just add a module to the Taranis in the same way you do to devo. There was something fundamentally different in the processing chain. So the only way to add modules is via the module bay. I don't know what the limitations of the bay is though. E.g can a universal module be made
You mean like this one? If you mean one where the software can control what it speaks, no, I don't think that's possible. The Taranis communicates with the module in the back via PPM, and the module generates the proper protocol from that.

Actually, you can add a module to the Taranis. People are doing the same hack to it to get DSM as they did to the 9X before there the Orange module was available. JustPlaneChris (from the RC Today show) talks about doing it to his. Basically, the DSM2 modules expect PPM in, so you just need to grab the signal from the right place in the Taranis.

I think what you can't do is change the protocol an existing module speaks. You have to have a module that swallows the signal after it's converted from PPM but before it's converted to RF in order to do that. The modules in the back want PPM. I'm not sure what the internal radio module wants.
May 20, 2014, 06:38 PM
Registered User
flickycity's Avatar

Daryoon's Devo 7e


Quote:
Originally Posted by Mike Meyer
You mean like this one?

Ha! Yes!
Something like that but with all the hisky/wltoys/hubsan protocols too.

Perhaps an open source module! So then it can be updated every time someone decides they need yet another protocol.

Edit: went searching and found this.
https://www.rcgroups.com/forums/show....php?t=2165676
Last edited by flickycity; May 20, 2014 at 06:52 PM.
May 20, 2014, 07:22 PM
Registered User
Mike Meyer's Avatar
Quote:
Originally Posted by flickycity
Ha! Yes!
Something like that but with all the hisky/wltoys/hubsan protocols too.
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I don't think you can have one module that does the hisky/wltoys/hubsan protocols *and* the DSM2/Walkera/J6Pro protocols. The behavior of the RF is different, so you need a different radio. Which is why you have to add one to the Devo Tx's to get those.

On the other hand, the pieces for building a module that does the H/W/H protocols are all at hand: the software is available from DeviationTx, you can use an A7105 module and a cheap microcontroller card for the electronics. There are boxes for modules available from thingiverse to put them in.
May 20, 2014, 07:24 PM
Go small or go home
ruzam's Avatar

Power usage


Well, after many hours of charging and timing my 7E run times (more exciting than watching paint dry, and peel, and fade into history...), here's what I found:

I'm using 2000 mAh enelopes in my 7E. Bought them from Costco years ago, because they were a heck of a deal and who doesn't want a rechargeable that doesn't self discharge over time. Didn't even consider using them for RC at the time. Takes 10-12 hours to charge in the 7E using a 12V 750mA power brick. It's nearly charged after 8 hours, but that last top up of the tank takes longer. All four batteries were within 0.03V fully charged and within 0.02V fully discharged, so I think all my batteries are good or at least equally bad (which seems unlikely).

To test, I setup the model/RF module then charge over night (5.44V showing on the transmitter). I turn the transmitter on, then set my phone stop watch and babysit it until the low voltage starts beeping (around 4.1 V). This way I only ever have one RF module powered up just in case there's a bug preventing modules from being shut off. Not that there might not be some bug anyway that powers all RF modules. Each test was run with the transmitter set to 150 mW full power (if that makes a difference). I tried to test each module a couple times, but really, this is painfully time consuming.

DSMX - stock RF module, Average - 3:00
Trial 1 - 3:35, Trial 2 - 2:30, Trial 3 - 2:56

SLT - A7105 (with power amp), Average - 3:46
Trial 1 - 3:46

HiSky - nRF24L01, Average - 4:16
Trial 1 - 4:20, Trial 2 - 4:12

So...
There's some variability. Maybe it's the number of times the 'idle' warning goes off before I twiddle the sticks, how soon after charging I started, temperature, who knows.

The built in Module has the worst run time and at 3 hours (avg), it's rather disappointing. I can see days in my future where lugging spare transmitter batteries will be concern. To me this says that at least one of the other modules is drawing power at the same time.

The nRF24L01 module had the best run time (by more than an hour). To me this says that the built in module (and/or the A7105) is being powered down while it's in use (or run time would have been much less than 3 hrs). This also suggests that the nRF24L01 is the power sucking culprit.

The A7105 is some where in between and needs more timing runs, but appears it may be about the same as the stock radio.

I'm going to try a few more run times with the A7105, but then I think the only way to be sure is to clip my carefully soldered wires and run timings again with the RF modules physically removed and then see what happens as I add them back one at a time.

I once left a parkzone RTF transmitter powered on over night and it's still running on the original factory AAs. I don't expect the 7E to get the same run time, given all the extra stuff going on inside, but 3 hrs is disappointing.
May 20, 2014, 07:33 PM
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ruzam's Avatar
Correction... I believe it's the nRF24L01 that has the power amp, not the A7105.

Now I'm wondering about the nRF24L01 wiring. The module pin labelled 'CE' is wired to positive. if 'CE' stands for Chip Enable, then the 'CE' pin might be what's turning on the power amp and it may need to be driven with an inverted 'CSN' to make it shut down when the module is not in use. More testing required...
May 20, 2014, 08:17 PM
low tech high tech
vtdiy's Avatar
Thanks Ruzam!

Looks like, as we figured, the internal charger probably puts out just about 5.45+ volts, so as the batteries approach that, the charge tapers off to nothing. Interestingly the Spektrum DX6i charges to 5.6 volts. My Devo 7e also charges to a little over 5.4 volts max.

Would it be helpful if I did a timed test on my non-module Devo-7e?

I use DSM2 btw, not DSMX, and I would guess the majority of Spektrum users do also. There are a lot more existing receivers out there with DSM2, and they continue to be high sellers for both Lemon and Orange.

I don't know if the Tx power consumption would be different for the different protocols..


ps. Have you ever put an ammeter temporarily in the batt line to see what the draw is for your protocols -- that would maybe allow comparisons with others having different batteries (like me with no modules installed) -- since that should be consistent.

Also it would allow you to know if you're getting a full 2000 mah out of your batts now.


Just realized I actually did that back last winter when checking to see if my full range mod had worked:

https://www.rcgroups.com/forums/show...1#post27395686

Here's another user's current draw (not clear which prtocol or module though)

https://www.rcgroups.com/forums/show...9#post27386989
Last edited by vtdiy; May 20, 2014 at 08:48 PM.
May 20, 2014, 08:32 PM
Go small or go home
ruzam's Avatar
Quote:
Originally Posted by vtdiy
Would it be helpful if I did a timed test on my non-module Devo-7e?
Couldn't hurt. Assuming our batteries are equal, I suspect it will last longer than my 3hr average. It would be surprising if it lasts much longer than 4hrs.

I don't think there would be a significant difference between DSM2 and DSMX power usage. They're both burning the same energy to push the same power out the antenna. The bigger difference should be the extra current draw of added RF modules I would think.

Easy enough to test by simply creating a test model config set for DSMX.
May 20, 2014, 08:52 PM
low tech high tech
vtdiy's Avatar
Sorry, I added a few edits above that you may not have seen.

It's looking like the Tx should be drawing 160-180 ma.

That's not jiving with 3-4 hours from a 2000mah batt
May 20, 2014, 09:11 PM
Go small or go home
ruzam's Avatar
I should probably just wire up a JST plug and socket so I can check the current draw directly with each module enabled/wired. Might not hurt to check the current draw of the individual modules too.
May 20, 2014, 09:18 PM
Registered User
Quote:
Originally Posted by flickycity
HK have the new R615X which looks interesting.
Hmm yes but not in Europe, that kills the deal for me. Also it looks like a "park-size" RX: I got two r400 and they are not enough for me as I said, I hope that is working good for you but I would recommend you to range test it on the ground before sending your new bird any far.

I got 3 lemons on the way, let's see how much time does it take.

Quote:
I haven't done the range mod yet or I'd test the R615 for you. (I'll try and do it today)
I bought the R615 for my mini breeze so I hope it's good enough!
That's perfect: I got one MB too
Morale: with r620 mine is good, I say it's good enough at 100mW as well.

Remember to tape the wings of the MB, if they separate and brake the plastic bar you're going through a hard time to replace that . It's a nice bird, I got it out this evening for some slow fly just over the grass (don't do that! Keep it very high for the first flights so you can recover!).
Last edited by eaman; May 20, 2014 at 09:32 PM.
May 20, 2014, 09:23 PM
low tech high tech
vtdiy's Avatar
Ruzam, good Idea -- I have a bunch of those leaded JST connectors -- think I'll do the same.
May 20, 2014, 09:32 PM
Team Drone Art
Daryoon's Avatar
Thread OP
Quote:
Originally Posted by Mike Meyer
I don't think you can have one module that does the hisky/wltoys/hubsan protocols *and* the DSM2/Walkera/J6Pro protocols. The behavior of the RF is different, so you need a different radio. Which is why you have to add one to the Devo Tx's to get those.

On the other hand, the pieces for building a module that does the H/W/H protocols are all at hand: the software is available from DeviationTx, you can use an A7105 module and a cheap microcontroller card for the electronics. There are boxes for modules available from thingiverse to put them in.
Not yet... but if PB's current project gets picked up by a manufacturer and built...it will be the closest thing.

Single-Board Universal Module
May 20, 2014, 09:35 PM
Registered User
Ok, just ordered the Devo 10. Thanks for the advice! Now I'm waiting for that blazing fast Banggood shipping. ;-)

Also, thanks for the friend codes. I had two in my account, but it was random draw so enjoy the kick back whoever got it!
May 20, 2014, 09:37 PM
Registered User
flickycity's Avatar
Quote:
Originally Posted by eaman
Remember to tape the wings of the MB, if they separate and brake the plastic bar you're going through a hard time to replace that . .

It'd be a good excuse to get a 3d printer to print one. Then I could also print that module case that Mike was talking about. Lol

Good luck with the lemons. What's with all the fruit names? Maybe we should call the devo 7e the goji berry coz it's a small superfood.


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