Hello,

need to connect new receiver to my exisiting flight controller and i'm looking for help.
Is the diagram posted below correct? Do I need something else?

RX   -------- FC

5v.  --------> Vin

GND -------> GND

S.port -----> Uart RX1?

FC Manual
RX Manual

Thank in advance :-)

Depends on the protocol that you are using.
S.Port or F.Port?

(09-Mar-2020, 06:14 PM)brnmd Wrote: Depends on the protocol that you are using.
S.Port or F.Port?

Well, i'm a bit new here...how can I choose/discover what protocol am I using?

The R9MM-FC-OTA receiver is designed to be used with FPORT firmware only because it only has S.Port and (un)inverted S.Port outputs, with no SBUS output.

So connect it as follows...

R9MM-FC-OTA         Flycolor X-Tower F4
===========         ===================
+5V --------------> Vin
GND --------------> GND
Inverted S.Port --> UART1 TX1

Then copy/paste the following block of commands into the Betaflight Configurator CLI text box and press <ENTER>.


Then test for stick movements in the Betaflight Configurator Receiver tab. If you get no response then run both the "dump" and "diff all" commands and post the results back here.

(09-Mar-2020, 07:17 PM)SnowLeopardFPV Wrote: The R9MM-FC-OTA receiver is designed to be used with FPORT firmware only because it only has S.Port and (un)inverted S.Port outputs, with no SBUS output.

So connect it as follows...

R9MM-FC-OTA         Flycolor X-Tower F4
===========         ===================
+5V --------------> Vin
GND --------------> GND
Inverted S.Port --> UART1 TX1

Then copy/paste the following block of commands into the Betaflight Configurator CLI text box and press <ENTER>.

Code:

feature -RX_PPM
feature -RX_PARALLEL_PWM
feature RX_SERIAL
feature TELEMETRY
serial 0 64 115200 57600 0 115200
set serialrx_provider = FPORT
set serialrx_halfduplex = ON
set serialrx_inverted = OFF
save

Then test for stick movements in the Betaflight Configurator Receiver tab. If you get no response then run both the "dump" and "diff all" commands and post the results back here.

Pardon me the silly question but as far as you know is there any Inverted S.port pad somewhere on the board? 
Because the board apparently got only a flat cable connector from where I can get the Inverted signal and for me it is almost impossible to solder on it... 

(09-Mar-2020, 07:41 PM)mivo Wrote: Pardon me the silly question but as far as you know is there any Inverted S.port pad somewhere on the board? 
Because the board apparently got only a flat cable connector from where I can get the Inverted signal and for me it is almost impossible to solder on it... 

Yes, that's a bit of a problem when using the R9MM-FC-OTA with an F4 flight controller. I don't believe there is a breakout pad anywhere on the board for (un)inverted S.Port, so your only option when using an F4 board is to carefully remove the ribbon cable from the receiver and then directly solder to the tiny (un)inverted S.Port pad that the ribbon cable connected to, or try to locate the inverter chip on the receiver and solder directly to the uninverted signal leg on that, but that will probably be more difficult than soldering to the ribbon cable pad. If you do try to solder to the ribbon cable pad then be really careful not to use too much heat because it is going to be really easy to accidentally burn or lift that pad, and if you do that it will be game over.

Alternatively if you use the R9MM-FC-OTA with an F7 flight controller that can natively handle an inverted signal, then you can just connect the normal S.Port pad to any UART TX pad.

(09-Mar-2020, 08:00 PM)SnowLeopardFPV Wrote: Yes, that's a bit of a problem when using the R9MM-FC-OTA with an F4 flight controller. I don't believe there is a breakout pad anywhere on the board for (un)inverted S.Port, so your only option when using an F4 board is to carefully remove the ribbon cable from the receiver and then directly solder to the tiny (un)inverted S.Port pad that the ribbon cable connected to, or try to locate the inverter chip on the receiver and solder directly to the uninverted signal leg on that, but that will probably be more difficult than soldering to the ribbon cable pad. If you do try to solder to the ribbon cable pad then be really careful not to use too much heat because it is going to be really easy to accidentally burn or lift that pad, and if you do that it will be game over.

Alternatively if you use the R9MM-FC-OTA with an F7 flight controller that can natively handle an inverted signal, then you can just connect the normal S.Port pad to any UART TX pad.

Thanks, invaluable help form you as always 

I'll figure out something with the ribbon cable as I have no F7 FC to work with ATM

(09-Mar-2020, 08:00 PM)SnowLeopardFPV Wrote: Yes, that's a bit of a problem when using the R9MM-FC-OTA with an F4 flight controller. I don't believe there is a breakout pad anywhere on the board for (un)inverted S.Port, so your only option when using an F4 board is to carefully remove the ribbon cable from the receiver and then directly solder to the tiny (un)inverted S.Port pad that the ribbon cable connected to, or try to locate the inverter chip on the receiver and solder directly to the uninverted signal leg on that, but that will probably be more difficult than soldering to the ribbon cable pad. If you do try to solder to the ribbon cable pad then be really careful not to use too much heat because it is going to be really easy to accidentally burn or lift that pad, and if you do that it will be game over.

Alternatively if you use the R9MM-FC-OTA with an F7 flight controller that can natively handle an inverted signal, then you can just connect the normal S.Port pad to any UART TX pad.

Somehow I managed to solder a cable over flat cable but now i'm facing some troubles trying to bind RX to TX...

Downloaded and installed flex firmware for tx and i was trying to do the same on rx using the servo cable connector (OTA mode apparently won't work till these two are binded) but when i try to select firmware on my Jumper TX16 i noticed it has a different extension, .frsk instead of the usual .frk and it is impossible to load it then...

Any clue?

(10-Mar-2020, 02:04 PM)mivo Wrote: Somehow I managed to solder a cable over flat cable but now i'm facing some troubles trying to bind RX to TX...

Downloaded and installed flex firmware for tx and i was trying to do the same on rx using the servo cable connector (OTA mode apparently won't work till these two are binded) but when i try to select firmware on my Jumper TX16 i noticed it has a different extension, .frsk instead of the usual .frk and it is impossible to load it then...

Any clue?

Those "frsk" files are ACCESS firmware files which won't work with your T16. You need to download and flash the ACCST firmware files. Click HERE and then expand the ACCST section and download the ZIP file from under that. There is only one firmware download for ACCST. You need to flash the R9MM-FC_FLEX_Fport.frk\R9MM-FC_FLEX_Fport.frk file from that ZIP file to your R9MM-FC-OTA receiver.

(10-Mar-2020, 02:39 PM)SnowLeopardFPV Wrote: Those "frsk" files are ACCESS firmware files which won't work with your T16. You need to download and flash the ACCST firmware files. Click HERE and then expand the ACCST section and download the ZIP file from under that. There is only one firmware download for ACCST. You need to flash the R9MM-FC_FLEX_Fport.frk\R9MM-FC_FLEX_Fport.frk file from that ZIP file to your R9MM-FC-OTA receiver.

Ok, got it.

Could you please point me toward the right TX file so everything is sorted out?

Thank you

(10-Mar-2020, 02:49 PM)mivo Wrote: Could you please point me toward the right TX file so everything is sorted out?

I guess you mean the firmware for the R9M module (?) Which version of the module do you have? The ACCST version (with "ACCST" written on the back), or the ACCESS capable version (with "2019" written on the back)?

(10-Mar-2020, 02:54 PM)SnowLeopardFPV Wrote: I guess you mean the firmware for the R9M module (?) Which version of the module do you have? The ACCST version (with "ACCST" written on the back), or the ACCESS capable version (with "2019" written on the back)?

ACCESS 2019. Guess the right one firmware to download for R9M module would be 1.2.0 access version

(10-Mar-2020, 03:07 PM)mivo Wrote: ACCESS 2019. Guess the right one firmware to download for R9M module would be 1.2.0 access version

Just to confuse you even more, no. None of the ACCESS firmware is compatible with your T16, which also means you will never get the OTA firmware update feature because that only works via ACCESS firmware.

For your R9M 2019 you need to download and install the latest version of the FLEX firmware labelled version 190117 and dated 2019-02-13. Just click HERE and then expand the FLEX section and download the ZIP file for that version. You will need to extract the R9M_FLEX.frk file and flash that to your R9M module.

In addition to installing the FLEX firmwares on both the R9MM-FC-OTA and the R9M 2019, you also need to make sure the "flexr9m" option is ticked for the version of OpenTX on your T16. If you're not sure then just re-flash the latest version of the OpenTX firmware (currently 2.3.5) with that option ticked. You can get that from HERE. If you don't install R9M FLEX enabled OpenTX firmware then your T16 won't be able to communicate with the FLEX enabled R9M module.

(10-Mar-2020, 04:00 PM)SnowLeopardFPV Wrote: Just to confuse you even more, no. None of the ACCESS firmware is compatible with your T16, which also means you will never get the OTA firmware update feature because that only works via ACCESS firmware.

For your R9M 2019 you need to download and install the latest version of the FLEX firmware labelled version 190117 and dated 2019-02-13. Just click HERE and then expand the FLEX section and download the ZIP file for that version. You will need to extract the R9M_FLEX.frk file and flash that to your R9M module.

In addition to installing the FLEX firmwares on both the R9MM-FC-OTA and the R9M 2019, you also need to make sure the "flexr9m" option is ticked for the version of OpenTX on your T16. If you're not sure then just re-flash the latest version of the OpenTX firmware (currently 2.3.5) with that option ticked. You can get that from HERE. If you don't install R9M FLEX enabled OpenTX firmware then your T16 won't be able to communicate with the FLEX enabled R9M module.

Now I understand why more and more people say Frsky made a complete mess with their firmware policy lately 

R9M_FLEX.frk downloaded and installed
The need of ticking "flexr9m" flag on opentx was probably the ONLY thing I got right from the start

I saw opentx provide different settings to use while binding: FCC, EU, 915, 868.

Got it working while using FCC protocol 

(10-Mar-2020, 04:22 PM)mivo Wrote: I saw opentx provide different settings to use while binding: FCC, EU, 915, 868.
Both devices should be 868 EU version, guess choosing EU protocol should work then 

It's the firmware that controls what region the hardware relates to. The advantage of the FLEX firmware is that it doesn't make the hardware either EU or FCC specific. Instead it allows you to dynamically select whether to use EU-LBT or FCC when you bind.

If you're in the EU then I recommend just selecting the EU option for binding with because you will then avoid clashing with the 900MHz frequency that is used for GSM communications in Europe.

The one disadvantage with the EU option is that it only allows you to select up to 500mW of power compared with the FCC option which allows up to 1W of power. But the reality is that unless you are doing proper long range, then 500mW should be sufficient. Also keep in mind that the legal maximum power limit in the EU for amateur radio communications without a license is 25mW anyway...which I'm sure everyone abides by