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

I follow the instructions on BG page, and also your post, dc59.. Not sure if I accidentally damage the board during my attempt to remove the pin n solder the wires.. Considering my soldering skill, probably I should use dupont wire instead of remove the pin..

VeGani wrote: I follow the instructions on BG page, and also your post, dc59.. Not sure if I accidentally damage the board during my attempt to remove the pin n solder the wires.. Considering my soldering skill, probably I should use dupont wire instead of remove the pin..

Would you post some pictures of your 7E wiring and hardware.ini setting?

cmpang wrote: finally get some time to wire up the new 4-in-1 module from Taobao. Connections are straight forward with the attached diagram.

Output power verified with my primitive spectrum analyser to be on par with the original 7e Devo and the other three add on modules.

Range tested with Devo RX601, WLToys V931 (KN), FrSky X4R, WLToys v911 (Flysky), JXD385 (V202),Syma Car (Syma X8) all to be on par with original.

I do ask the seller about the PA/LNA issue. The reply is all done within the modules. No further explaination given tought..

cmPang

Is this the same picture of 3-in-1 installation on BG?

kahuna001 wrote:

Left original Rev and Right Current.

The small 12pin chip looks like 2.4GHZ CMOS SP3T ANTENNA SWITCH RFX333 ( www.skyworksinc.com/uploads/rfx/RFX333_DataSheet.pdf )
The big 8pin chip must be a MCU, maybe one of those ATTiny chips
Don"t know why their markings needed to be removed....

The chip maybe like 4in 1 is similar CD4052 multiplexer.
The control can be via PA /LNA pins and CD4052.

Hi,

How to connect this 3in1 FR module on Devo 12S ? Especially the PINs on the main board that we could use ( for example like the B7 on Devo 10)

Photo of DEVO 12S board :

midelic wrote: The chip maybe like 4in 1 is similar CD4052 multiplexer.
The control can be via PA /LNA pins and CD4052.

The switch has to be a RF-specific chip.

Can somebody restate the exact issue we have with this 3-in-1 module that has been sold so far? Is there a way to fix it?

I will try to redo my wire soldering on this module first.
BTW, earlier I've installed module A7105 from my V911 transmitter according to DeviationTx manual. Should I remove this module before I install this 3in1, or both can be installed at the same time with the same wiring and hardware.ini shown on BG page?

HappyHarry wrote:

wasp09 wrote: The dead original RF module in my 7e was different from the 8S module I replaced with. The original module was marked 6S. Devo 6S does not use 6S RF module then.

the main board on the 7e is marked 6f, was that not what was on the module?

wasp09 wrote: YJ,
It is still a mystery on how the 3 in 1 controls the X2401C on board. Current alone does not tell us everything, like whether the X2401C is switched into LNA mode if we need to receive.

Regards,

there is no lna for the a7105 and nrf24l01 on the 3in1 board, and as of the latest shipment from banggood there have been no changes to the 3in1. when i find time tonight i'm going to review it on BG to let people know of this as some stuff requires this to bind as well as telemetry

[edit]
i was too slow lol
[/edit]

On TaoBao's 3-in-1 page the seller mentioned its limitation :

"高频头带有功率放大器（PA）和低噪声放大器（LNA），由于DEVO系列固件不提供相关控制功能，所以只能默认发射时开启PA，接收时不能开启LNA，也就是说，支持发射功率放大，也可以接收回传数据，但是回传距离有限。"

"The RF module has the PA and LNA. Due to the fact that Devo firmware doesn't provide corresponding control function, it can only turn on the PA by default when transmitting and can not turn on the LNA when receiving. In other words, it supports transmission power amplification and also supports receiving telemetry data with limited distance"

valley_nomad wrote: Don"t know why their markings needed to be removed....

I asked TaoBao seller (3in1 board designer) about this question, he told me as he know there is someone trying to clone this board,
he must protect his product , that is why he removed the mark on some chip.

VeGani wrote: I will try to redo my wire soldering on this module first.
BTW, earlier I've installed module A7105 from my V911 transmitter according to DeviationTx manual. Should I remove this module before I install this 3in1, or both can be installed at the same time with the same wiring and hardware.ini shown on BG page?

There is a A7105 in 3in1 module already, you don't need A7105 from V911 TX, just remove it!

valley_nomad wrote:

HappyHarry wrote:

wasp09 wrote: The dead original RF module in my 7e was different from the 8S module I replaced with. The original module was marked 6S. Devo 6S does not use 6S RF module then.

the main board on the 7e is marked 6f, was that not what was on the module?

wasp09 wrote: YJ,
It is still a mystery on how the 3 in 1 controls the X2401C on board. Current alone does not tell us everything, like whether the X2401C is switched into LNA mode if we need to receive.

Regards,

there is no lna for the a7105 and nrf24l01 on the 3in1 board, and as of the latest shipment from banggood there have been no changes to the 3in1. when i find time tonight i'm going to review it on BG to let people know of this as some stuff requires this to bind as well as telemetry

[edit]
i was too slow lol
[/edit]

On TaoBao's 3-in-1 page the seller mentioned its limitation :

"高频头带有功率放大器（PA）和低噪声放大器（LNA），由于DEVO系列固件不提供相关控制功能，所以只能默认发射时开启PA，接收时不能开启LNA，也就是说，支持发射功率放大，也可以接收回传数据，但是回传距离有限。"

"The RF module has the PA and LNA. Due to the fact that Devo firmware doesn't provide corresponding control function, it can only turn on the PA by default when transmitting and can not turn on the LNA when receiving. In other words, it supports transmission power amplification and also supports receiving telemetry data with limited distance"

It may be more than a matter of not having a LNA. The "PA" chip, say RFX2401C, has both PA/LNA. It is sitting in between the RF chips and the antenna. Unless the board has a way to bypass the "PA" chip and connect the RF chips to the antenna on receiving, the reception could be way worse than just not having a LNA especially if the RF chips are sitting inside a metal shield.



Besides enabling PA or LNA, the chip can be powered down. However the insertion loss between TXRX and ANT would be something like 50dB, not really passing through...

Regarding the devo code not providing control, it does control PA/LNA switching on standalone RF modules using outputs from the RF chips, on A7105 through setting GIOPIN1 and 2 (see A7105_SetTxRxMode), on CC2500 through setting IOCFG0 and IOCFG2 (see CC2500_SetTxRxMode) and on NRF24L01 by setting TX mode which changes VDD_PA (see NRF24L01_SetTxRxMode). As I said before either the MCU onboard has to listen in the spi or it has to monitor those IO/VDD_PA pins to know about mode changes. It probably is too complicated for hardware multiplexer to decode them directly. Perhaps it is time for the N in 1 board suppliers to tell the deviationtx developers what the boards need to work correctly. It looks like extra control pins are already there on board, we just need to know how to make use of them.

BTW, CD4052 probably won't work too well for switching 2.4GHz.

wasp09 wrote: ... It may be more than a matter of not having a LNA. The "PA" chip, say RFX2401C, has both PA/LNA. It is sitting in between the RF chips and the antenna. Unless the board has a way to bypass the "PA" chip and connect the RF chips to the antenna on receiving, the reception could be way worse than just not having a LNA especially if the RF chips are sitting inside a metal shield.
.....
Besides enabling PA or LNA, the chip can be powered down. However the insertion loss between TXRX and ANT would be something like 50dB, not really passing through...
......
Regarding the devo code not providing control, it does control PA/LNA switching on standalone RF modules using outputs from the RF chips, on A7105 through setting GIOPIN1 and 2 (see A7105_SetTxRxMode), on CC2500 through setting IOCFG0 and IOCFG2 (see CC2500_SetTxRxMode) and on NRF24L01 by setting TX mode which changes VDD_PA (see NRF24L01_SetTxRxMode). .....

OK. My understanding is that this 3-in-1 module almost doesn't have receiving capability at all, which is WORSE THAN the separate RF module approach.

valley_nomad wrote:
On TaoBao's 3-in-1 page the seller mentioned its limitation :

"高频头带有功率放大器（PA）和低噪声放大器（LNA），由于DEVO系列固件不提供相关控制功能，所以只能默认发射时开启PA，接收时不能开启LNA，也就是说，支持发射功率放大，也可以接收回传数据，但是回传距离有限。"

"The RF module has the PA and LNA. Due to the fact that Devo firmware doesn't provide corresponding control function, it can only turn on the PA by default when transmitting and can not turn on the LNA when receiving. In other words, it supports transmission power amplification and also supports receiving telemetry data with limited distance"

that's an outright falsehood, deviation does indeed have control for pa/lna switching for all of the modules, so it's clearly a limitation of his design, plus it isn't mentioned on banggood where most of us non chinese reading people purchased these from. it needs to be made clear on banggood to stop other people purchasing them under false pretenses (as well as the 4in1 issues midellic and pascal found), unfortunately bangood doesn't seem to be willing to post my review that mentions these issues, even though i clearly purchased 3 of the 3in1's.

I also have also doubts about RF path of this module, at 2.4ghz any length few mm of pcb line, causing loss or impedance mismatch, unless really proplerly designed. striplines.

It would be much better if the RF outputs of each chip oriented with its rf output, directly connected to the 3way switch. Also the antenna output stripline after the LNA has some low pass capacitors, I hope this is designed properly.
In my opinion would be more optimal keep RF output very short and use a ceramic bandpass filter for 2.4ghz as some other modules use, at least then be sure the output has no loss.

And indeed the pa//lna pins must be switched.

HappyHarry wrote:

valley_nomad wrote:
On TaoBao's 3-in-1 page the seller mentioned its limitation :

"高频头带有功率放大器（PA）和低噪声放大器（LNA），由于DEVO系列固件不提供相关控制功能，所以只能默认发射时开启PA，接收时不能开启LNA，也就是说，支持发射功率放大，也可以接收回传数据，但是回传距离有限。"

"The RF module has the PA and LNA. Due to the fact that Devo firmware doesn't provide corresponding control function, it can only turn on the PA by default when transmitting and can not turn on the LNA when receiving. In other words, it supports transmission power amplification and also supports receiving telemetry data with limited distance"

that's an outright falsehood, deviation does indeed have control for pa/lna switching for all of the modules, so it's clearly a limitation of his design, plus it isn't mentioned on banggood where most of us non chinese reading people purchased these from. it needs to be made clear on banggood to stop other people purchasing them under false pretenses (as well as the 4in1 issues midellic and pascal found), unfortunately bangood doesn't seem to be willing to post my review that mentions these issues, even though i clearly purchased 3 of the 3in1's.

Additionally according to RF path in RFX2401C the statement on 3-in-1 module's capability of receiving telemetry data with limited distance may also be false

CD4052 on 4in1 module and is not used for switching 2.4Ghz.It is connected with PA/LNA chip TXEN pin and PE1 PE1 Peregrine antenna swicth pins.
If you check data sheet of CD4052 you'll understand how it is working

midelic wrote: CD4052 on 4in1 module and is not used for switching 2.4Ghz.It is connected with PA/LNA chip TXEN pin and PE1 PE1 Peregrine antenna swicth pins.
If you check data sheet of CD4052 you'll understand how it is working

I see. It looks like a fix here

Yes I'm preparing for a fix on A7105 and NRF 24L01 LNA.
I need to remove the pullup 4.7K resistor on TXEN pin cut 3.3V trace corresponding to A7105 and bridge togheter CD4052, pin12 with pin 11,and modify code for using CYRF XOUT switching A7105 to LNA.

midelic wrote: Yes I'm preparing for a fix on A7105 and NRF 24L01 LNA.
I need to remove the pullup 4.7K resistor on TXEN pin cut 3.3V trace corresponding to A7105 and bridge togheter CD4052, pin12 with pin 11,and modify code for using CYRF XOUT switching A7105 to LNA.

That is for 4-in-1?
The solution for 3-in-1 may be a bit different if it uses RFX333 as switch which has three control bins.