I have a GEPRC TinyGO (race edition without 4k DVR) and also a pair of DJI FPV V2 goggles for another drone. Instead of getting an analog adapter for the goggles I'd like to mount a Caddx Vista to the TinyGO (removing TinyGO VTX and antenna). The extra weight is no issue, I've added 30 grams to the TinyGO and flown it around indoors for testing, it's fine for indoor (which is the sole reason why I bought the TinyGO).

Adding the Caddx Vista and powering it should be simple enough. From what I have read, it can run down to 6V, but I'd like to see battery voltage and in the goggles too. Is it possible for the Caddx Vista to get the OSD information from the GEP-F4-12A V1.4 flight controller to display in the DJI goggles? I've done some searching but haven't found anything yet. If it can be done, does anyone have any pointers on the wiring?

Do you have a Dji Radio or are you using Geprc kit radio?

Looking at this photo from Geprc, you need to power the caddx from the AIO FC  battery pad and connect the Caddx TX, RX to the UART 2 RX  TX located near the Geprc logo.

Then turn on   Configuration/ MSP 115200 on UART 2 on the BF Port tab and then configure your Betaflight OSD. 

If you plan to use dji radio,  you will need connect the sbus wire from the Caddx to the FC and configure  serial rx on  the Port tab.

The problem with the GEPRC GEP-12A-F4 AIO FC is that it only has two UARTs. UART2 has both RX and TX pads broken out and has been dedicated for use with a receiver. UART1 only has the TX pad broken out for use with SmartAudio.

The way to get around this limitation and what GEPRC do on the Thinking P16 is to remap the UART1 TX pad (T1) and the LED pad to a SoftSerial port and then use that for the MSP connection to a DJI Air Unit or Caddx Vista in order to provide the OSD and arming signals.

Connect the RX output of the Caddx Vista to the T1 pad on the FC and connect the TX output of the Caddx Vista to the LED pad on the FC. Then run the following commands in the CLI to remap the UART1 and LED pads to the SOFTSERIAL1 port, and configure it to be for an MSP data connection...


Keep in mind that SoftSerial has a much slower baud rate than a hardware UART and people have experienced intermittent problems with the OSD elements freezing in the DJI FPV Goggles when using SoftSerial for the MSP data connection to a Caddx Vista / Air Unit.

Thanks! I have not seen that info.

I'll be sticking with the GEPRC kit radio.

(01-Mar-2022, 03:12 PM)SnowLeopardFPV Wrote: The problem with the GEPRC GEP-12A-F4 AIO FC is that it only has two UARTs. UART2 has both RX and TX pads broken out and has been dedicated for use with a receiver. UART1 only has the TX pad broken out for use with SmartAudio...

Nice information once again, thanks. It might be a bit over my head, at least for now but I'll be giving it a go.

I just found some additional documentation, posting for reference if someone stumbles onto this thread when searching on the topic.

It's the manual of v1.3, it has a bit more DJI specific information than the v1.1 manual posted above: https://geprc.com/wp-content/uploads/202...l-V1_3.pdf

Good work both.

Please ignore my earlier post.

I got it working so I'm adding some information if someone should come across this thread looking for the same information as I was (adding Vista to TinyGO and keeping original receiver).

This is a picture from the GEPRC v1.3 flight controller manual that I've edited. I've removed the connections and betaflight command line I didn't use. It's now an exact picture of what SnowLeopardFPV posted above and is exactly what I had to do to get it to work:



I soldered wires from the Vista to the TinyGO FC:



I had to cut some plastic off the canopy for the Vista to fit. On the right you can see what I ad to cut off,  I of coarse had to cut right side off too. I'm assuming the Caddx Loris is attached to these on the 4k TinyGO (I have racing version without DVR):



Now it fits in under the canopy:



I put screws through the top of the canopy and into the Vista unit. It's not pretty but holds the Vista in place, at least for now:



So it fits and is mounted well enough for indoor test flights:



Center of gravity might be a little off and with my current cells I get about 5 minutes flight time instead of 6 with the extra weight, but for indoor flying it's all worth it in order to fly digital with my DJI goggles. Maybe I'll try stripping the heatsinks from the Vista to get weight down, only running at 200mW indoors anyway, and I'll probably have to fix better mounting as those screw holes in the canopy won't hold for long, but all in all I'm happy so thanks for the help!