Devo 12s 3in1 / 4in1 RF module neat installation.

victzh wrote: Old module should not have a problem with nRF, only with A7105 - it does not have any connection to PA/LNA enable. nRF is connected and should work both with telemetry and auto acknowledge.

Regarding NRF AA support, do you maybe know if NRF used is genuine or clone? There is known problem with AA with payload on clones talking to genuine chips. One single bit is flipped and AA with payload simply doesn't work.

Hi Victzh,

Old module should not have a problem with nRF, only with A7105 - it does not have any connection to PA/LNA enable. nRF is connected and should work both with telemetry and auto acknowledge.

From my experience this is not correct for the 4in1 module.
For the A7105, it is obvious that the associated TXEN entry on the 4052 is set to VCC so the PA is always enabled.
For the NRF24L01 the PA is also always active but it's due to how the signal is treated. TXEN is connected to the NRF VDD_PA pin through the 4052. But since there is an additional pull-up on the TXEN pin, the VDD_PA signal has a large offset to 1.8V (when in RX mode) and 2.2V (when in TX mode). From the RFX2401C datasheet a "1" is 1.2V or more so in fact TXEN is always seen as a "1" and PA is always active. You can easily verify this using a scope and looking at the TXEN pin of the RFX2401C. I've checked it with a couple of models and the range in RX mode is only 2-3 meters.

The Cyrf and CC2500 are both able to switch TXEN state perfectly fine.

- Pascal

Interesting. I'll discuss it with the producer of these modules, if someone else did not tell him already. He's definitely going to fix A7105, but maybe he's unaware about the situation with nRF.

seems like i may have lucked out by missing the first batch of 3in1's if these issues's are going to be fixed in future versions

For those curious, the MM source code is in the deviation source tree in utils/multi-module/switch.c.

It is not Arduino code. It may well compile with the arduino IDE, but uses the AVR hardware abstraction layer, not the arduino one, so you don't need it.

The win for the 4-in-1 is that you only need one antenna. Sure, it may be an alternative to the "diode" mod, but it's not the only one, and has no clear advantage over the alternatives except that single antenna. And yes, it will require some kind of circuitry to do the switch.

Is this safe to buy now, or should we wait for the next version?
www.banggood.com/2_4G-CC2500-A7105-Flysk...OV1215528682201404B8

also, what do you figure is the difference between the frsky, flysky, and JR base plates versions?

Will be possible to connect a rp-sma T , to link the 3in1 module & stock module to do one single antenna?
Like this: www.aliexpress.com/item-img/Adapter-RP-S...1F2M/2024966695.html

Will work? Or will produce interferences or similar?

mwm wrote: For those curious, the MM source code is in the deviation source tree in utils/multi-module/switch.c.

It is not Arduino code. It may well compile with the arduino IDE, but uses the AVR hardware abstraction layer, not the arduino one, so you don't need it.

The win for the 4-in-1 is that you only need one antenna. Sure, it may be an alternative to the "diode" mod, but it's not the only one, and has no clear advantage over the alternatives except that single antenna. And yes, it will require some kind of circuitry to do the switch.

Thank you both for the info about MM source code location. I am aware that it is not arduino code. I was referring to github.com/pascallanger/DIY-Multiprotoco...master/Multiprotocol when I made comment about .ino files

And regarding 4-in-1 I am exceptionally excited about single antenna thing. Even with those current buggy modules it is great to see development going right direction.

Got the message below from BG. Does it mean 3-in-1 module will be delayed further even without a restocking date?

"... I'm sorry to tell you that the item CC2500 NRF24L01 A7105 Multi RF 3 IN 1 Wireless Module for DEVO Transmitter
still out of stock now.And I'm not sure when it will be restocked.Would you mind waiting for it or cancelling your order？

Looking forward to your early reply.

Carry"

ursus69 wrote: Will be possible to connect a rp-sma T , to link the 3in1 module & stock module to do one single antenna?
Like this: www.aliexpress.com/item-img/Adapter-RP-S...1F2M/2024966695.html

Will work? Or will produce interferences or similar?

T will not work correctly - you'll have the signal at the output but you never know whether it will ruin another chip. There should be a switch, which 3in1 and 4in1 modules have. Also, part of the signal will dissipate in another RF chip and the output will be less than for any module alone.

victzh wrote:

ursus69 wrote: Will be possible to connect a rp-sma T , to link the 3in1 module & stock module to do one single antenna?
Like this: www.aliexpress.com/item-img/Adapter-RP-S...1F2M/2024966695.html

Will work? Or will produce interferences or similar?

T will not work correctly - you'll have the signal at the output but you never know whether it will ruin another chip. There should be a switch, which 3in1 and 4in1 modules have. Also, part of the signal will dissipate in another RF chip and the output will be less than for any module alone.

Agree. Does anyone have the 3-in-1 schematic? Does it use PE42641 as RF switch too? If so, maybe we can hack it such that it can control the stock Devo RF as well

Uh-oh! Good luck soldering to an input of the switch while preserving integrity of the signal! And as far as I know inside 3in1 there is a microprocessor handling the switching. So you'd need to modify its firmware too.

I am looking for pin connections for a 3-in-1 module on a devo 8.
I am also looking for a copy of an hardware.ini or tx.ini file for a devo 8 with the module installed.
My deviation version is devo8-v 4.0.1 ef0d76d.

@christx:
See page 7 of this thread, dc59 posted some photos:
www.deviationtx.com/forum/7-development/...dule?start=120#44256
You can also find Tompeer's posts on page 5 and before

There are so many names around.
Not sure what means devo compatible board.
The multi Rf module 4in1 or 3in1 sold at BG is not build or designed by me or Pascal.So I cannot provide any diagram for multi Rf module.
Nobody asked us anything just dropped on the market with the link to our RGC thread.

The base board on 4in1 used is designed(not by me) from an older version of multiprotocol diagram that used only PPM out

Si in order to work with multiprotocol we did some small modifications.
For the tests we made the PA on A7105 and nrf24L01 is enabled(VCC)automatically.That problem still needs to be fixed.
So there are problems with Hubsan telemetry and binding, along with ack binding on nrf protocol that uses that.
www.rcgroups.com/forums/showpost.php?p=34517982&postcount=3516

Our diagram for multiprotocol and code you can find here.
github.com/pascallanger/DIY-Multiprotocol-TX-Module

It was a confusion that my name is in it.
The user dc59 kept contact with the manufacturer and release these photos .
It appears that the LNA issues with A7105 and nrf it will be fixed in the next board revision.

I think also on the existing board it can be done some HW hacks to solve this issue.
There is also 2 x 4-Channel multiplexer chip CM052B (4052)connected with antenna switcher.
www.datasheetq.com/CM052B-doc-TI

Some findings on CM052
""First half of it is completly connected to ground (pin 1 to 8 ) second half: X common is +3.3V. A and B are connected but not fully shared with the antenna switcher. "
The problems encountered are:
The entry(CM052) which is supposed to be connected to the A7105 is in fact connected to 3.3V.
The entry which should drive the pin TXEN to 1 or 0 from the NRF24L01 has a big pull up which completely shift the level of the control signal making it useless and force TXEN to 1.