7e/Ultimate7e, adding the devo version 4in1

[EDIT]The deviation version 4in1 board is now available at banggood

here are links to the 4in1, a ufl to sma pigtail and a 3dbi dipole antenna that will work for this modification.

Deviation 4in1 >> www.banggood.com/CC2500-NRF24L01-A7105-C...itter-p-1096707.html
ufl<sma pigtail >> www.banggood.com/10cm-PCI-UFL-IPX-to-RPS...-Cable-p-924933.html
3dbi dipole antenna >> www.banggood.com/2_4GHz-3dBi-RP-SMA-Conn...Router-p-979407.html

after photobucket's awful service change (they want $400 a year to allow showing your pictures on a 3rd party site/forum/blog etc!) my pictures are no longer showing properly. So i will need to swap all images to another provider and then update all forum links etc, I have a lot of hobbies/forums/posts to cover so in the interim here is a link to the album where the photos from this thread are stored >> Photobandit u7e 4in1 swap album
[/EDIT]

thanks to cmPang I was able to get a hold of one of the new 4in1 modules that have a daughterboard specifically for use with deviation, they are pretty much plug and play bar 3 wires in the d10 (possibly the d6/8/12 also?) as it uses the same 10pin 2mm pitch header. unfortunately the 7e's rf board is soldered in so we have to do a little more work. first up as this module contains all 4 rf chips we no longer need the stock rf board so I removed it, as it was soldered in the factory using lead free solder you will make life much easier for removal if you add a bit of leaded solder before wicking the solder off the 3 corners. be careful when desoldering the 7 hookup points as it's easy to lift a trace (I thought I had got away with it but when I went to solder the 5v line it just lifted off :/ ) here's the board with the rf module removed.



once that's done it's time for the trickiest part, we need to solder a wire to the mcu to use to enable the 4th rf module, if you have a look at silpstreams great howto on adding pots to the ult7e here >> Ultimate7e adding pots you will find a nice method of singling out the required pin using kapton tape. use pin 50 on the mcu, this equates to A15 in hardware.ini. in the following picture the yellow wire is the one in question, the other 2 wires soldered to the mcu are for the pots (see above tutorial by silpstream) and are not part of the 4in1 install.

next up is wiring in the actual module, I removed the 10pin header and soldered directly to the board, following the wiring diagram shared by cmPang (I've copied to this post) hook up the 4in1 to the 7e's pads

wiring guide and module hookup pics





(note that I had to use an alternate point to source 5v, it would usually be taken from pin6 of the rf board pins)

and that's the difficult part done, all that's needed now is to modify the hardware.ini to suit the wiring points, fit an antenna and go fly. though as I'm not keen on the rf path used on this daughterboard I'm going to modify it slightly, I'll be doing that tomorrow so I'll post details on that when it's completed.

Fantastic , HH.

Nice! Is there a product link yet? I have like 1400 BG points saved up, I want one!

Nice one HappyHarry! I'll add it to the wiki.

thanks guys, CK it's not fully available yet, why I don't know but I'm sure it'll show up on taobao and banggood soon.

ok to carry on from yesterday it's time to sort the antenna, although the module has an ufl antenna connector I'm not keen to use it, being as the trace that comes from the side of the 4in1 to that ufl is unsheilded, and measures ~32mm it's almost a perfect 1/4 wave monopole antenna! after some discussion and then reading up on this matter it turns out that the existing ufl connector and it's trace are perfectly fine to use, there is no reason to modify as i have done and you can find links in the first post for a ufl to sma pigtail that you can use instead.



so to get rid of this I just broke the trace where it connects to the 4in1 board, I just used a hobby knife and scored the copper away as below



I could have reused the antenna from the stock 7e module but I'm taking the opportunity to mount an sma header so I can use a proper removeable dipole antenna, so I prepared and soldered the antenna header direct to the 4in1 contact points



next up I took my lathe with a parting tool () and modified the stock antenna tube by cutting it off about 2-3mm above the point where it changes from the thick part to the thin, this leaves enough of a ridge for the sma header to sit against without pulling right through



after cutting



with that done it was simply a case of feeding the header through and tightening the holding nut, fitting the antenna and placing it on the tx



and that's the job done. I'm almost to the point of having the 7e I always wanted, multi protocol with a single repositionable antenna, and enough switches and a few pots to fully utilise deviations available channels, when it gets to that point it will be able to replace my dsm9x!


thanks to PB and Silpstream all i have to do is just finish wiring up the extra switches and pots and it's all the way there , the ultimate 7e, the $100 cost tx with capabilities way way above it's price point!

That looks really sweet! Gotta get myself one of those boards. I love the antenna mod. Any idea how range was affect pre and post mod?

it does make it a clean looking install compared to the separate modules eh, though the main thing i like about it is that all 4 rf chips now have a good antenna without making my tx look like a porcupine lol. the range between using the stock 7e antenna and this antenna shouldn't be any different as they are both 2db gain dipole's, (though with the sma header i can use larger gain antennae if i wanted) but now i can position the antenna for the best polarisation direction instead of it being in a fixed position. as for the difference between using the stock ufl and my modded version i'm not sure, like i said above that trace is 1mm longer than a perfect 1/4 wave monopole antenna and there's no way i'd have flown with it as such, although i'm no rf guru i'm pretty sure a lot of the tx power would have radiated away before even reaching the ufl connector. and while the pcb trace might work well as an antenna on it's own, i didn't want to take that chance

as for range vs using separate modules cmPang and dc69 have both posted favourable reports, and as i now have another ult7e that does have all 3 separate modules i'll be able to test back to back, though they are all using internal antennae so the results should be slightly skewed in the 4in1's favour. i just hope he's addressed the pa/lna and telemetry issues with the nrf and a7105 in this recent 4in1 board.

I probably know less than you about RF. Thanks for the info! I'll probably modify the antenna the same way once I get my hands on the new 4in1.

good job hh..
now that i have been flying and boating for 3 weeks, i can say that i see no difference in rf performs from the stock cyrf and the previous cc2500 （frsky） add on module.

since i have no long range models in nrf2401 and a7105, i cannot be certain on these two. but i do tested my v911 （flysky）and v931 （kn）and all is fine，（ on version 4.01）

@HappyHarry, if you are talking about the trace from RF module to the U.FL connector, its length can't be taken in consideration in isolation. What is important that's the impedance of the trace - it should match the impedance of the RF module and impedance of the antenna. This trace is so called "transmission line" and if all impedances match everything is OK. They should all be 50Ohm. Does this trace have impedance of 50Ohm - I don't know. It looks like one of the possible type of transmission lines - edge coupled microstrip, but the sizes don't look like valid 50Ohm line. Also, there is a rule that if some line is less than 1/10 of wavelength you shouldn't bother. If more - impedances better match. So everything shorter than 1.2cm is OK.

the key is everything is matched along the whole length.
for those pcb that uses a short length of wire as antenna then the length of the pcb trace would comes into play.
with a proper rf connector and antenna then the trace can be any length as long as its physical charastic matches as a transmission line

Hi HH,

Is there any power issue about 7E+4in1 module ?
LDO has enough current for 4in1 module?
Thanks.

Amazing modding want the same ....
-256Ko
-4in1
-2x3 extra switches
- 2 pots ....


OMG... I think I will buy a new 7E to build such project

SeByDocKy wrote: Amazing modding want the same ....
-256Ko
-4in1
-2x3 extra switches
- 2 pots ....


OMG... I think I will buy a new 7E to build such project

You can actually do 4x 3-way with 2x 2-way switches and 2x pots.

If you do do this, please record it into one of your amazing tutorial videos.

victzh and cmPang thanks for the info, like I said I'm no rf guru so I appreciate that my thinking may have been off. but as my setup now matches the 4in1/jr daughterboard antenna position it should be ok?

dc59 the 4in1 devo version doesn't use the 3.3v line it takes 5v, so the ldo isn't being used to power it

yeah thanks to pb and silpstream 2pots, 4x3ways and 2x2ways are now possible, and that's where this birds nest of wires is heading




and you can lay bets i'll never have the idea to crimp kynar wire into servo connectors again :/



that was not fun to do lol

well she's now complete, the ultimate7e I've always wanted! here's how the switch and pot wiring ended up



and the completed tx (minus it's sticks )


it's a beautiful sunny day and I was away to go flying, till I remembered that I lost all my model ini's when my original 7e turned up it's toes, so I'm away to do some programming first lol

again I want to thank pb for developing the ult7e, and silpstream for improving it and giving us nice easy to follow howto's

How can I get one of these as quickly as possible?
I just killed my stock module after trying out the range mod today (too much heat, so things around started floating out of place) and I'd like to use one of these, so I can get back to flying asap

How beautiful is the final result .... Want one want one want one


Question? Why you didn't use the original uFL/IPX connector ?

TheMadCADer the devo 4in1 is not readily available yet, I was only able to source it due to the kindness of another member of this forum. I'm sure they will turn up on taobao and banggood soon enough though, but if you can't wait there is always the 3in1 board which is compatable with the 7e.

seby I didn't use it due to my ignorance of rf antennae, I thought the bare copper trace from the 4in1 to the ufl would act as an antenna due to it being ~32mm long, but victzh and cmPang informed me that that's not the case and it would be fine using it