I ordered a GEP-M10-DQ GPS module from GEPRC and the pinout diagram shows that it needs connections to the SDA and SLC pins on my flight controller. The controller that I have is a GEP-F722-45A AIO V2 (Cinebot 30) and I don't see how/anywhere to connect the SDA and SCL pins on the flight controller. Where are these pins located, or does my flight controller not support these connections?

Thanks in advance.

GPS Module
Flight Controller

The Gep-f722 flight controller ( I think it's the HD version) shows SDA going to R3 and SCL going to T3. Not sure if that is the same for yours.
http://myosuploads3.banggood.com/product...EN-V10.pdf

The SDA and SCL connections are only required if you want to use the compass and barometer on the GPS, otherwise you can leave them disconnected.

If you do want to use them, they can be wired to UART3. Connect SDA to RX3 and SCL to TX3. You will need to reflash Betaflight in expert mode and include the custom defines for your compass and baro:
`BARO_DPS310 MAG MAG_QMC5883`

A compass is pretty much useless in Betaflight unless all you want is a visual indicator in the OSD for the compass direction you are heading, but unless you put the module up high well away from the quad electronics and mount it at the right angle for level orientation when flying forwards, in most cases it won't give you a reliable or correct reading, and if it gets used for GPS Rescue with an incorrect reading you risk a flyaway.

Unless you have a specific use case for a compass on your quad then I would either abandon the idea entirely and just leave the compass SDA and SCL connections disconnected, or consider using INAV instead of Betaflight.

I agree the compass is not useful with Betaflight right now, but the barometer is very helpful for altitude and RTH.

Hey guys, thank you so much for your feedback and responses. I'm still new to all this, but if I understand things correctly can I do the following for the soldering:

GPS      FC
TX  ->  RX1
RX  ->  TX1
GND-> GND
5V   -> 5V 
SDA -> RX3
SCL  -> TX3

Thanks again!

(27-Jul-2023, 01:59 PM)sdtrent Wrote: Hey guys, thank you so much for your feedback and responses. I'm still new to all this, but if I understand things correctly can I do the following for the soldering:

GPS      FC
TX  ->  RX1
RX  ->  TX1
GND-> GND
5V   -> 5V 
SDA -> RX3
SCL  -> TX3

Thanks again!

This is correct.

I would not bother with SDA -> RX3 and SCL -> TX3, in other words I'd just wire it like the M10 (non DQ version).

However, it does have a barometer, you might want to use it. You can solder them but first concentrate on getting the GPS unit working, then fiddle around with the other stuff.

(27-Jul-2023, 08:20 PM)Mike C Wrote: I would not bother with SDA -> RX3 and SCL -> TX3, in other words I'd just wire it like the M10 (non DQ version).

However, it does have a barometer, you might want to use it. You can solder them but first concentrate on getting the GPS unit working, then fiddle around with the other stuff.

Hmm ya that would be a smart move. Once my drone comes in next month I will be sure to report back. Thanks again for the tips and advice everyone!

Hi guys, I have the similar problem. I have mark5 quad with F722-BT-HD v2 and ELRS RX which is connected to UART3. So I can't use it for SDA and SCL. UART 2 is also occupied by O3 unit. So I'm a bit confused where I have to wire at least a barometer. Can someone help me?

(15-Oct-2023, 03:07 PM)helgi Wrote: Hi guys, I have the similar problem. I have mark5 quad with F722-BT-HD v2 and ELRS RX which is connected to UART3. So I can't use it for SDA and SCL. UART 2 is also occupied by O3 unit. So I'm a bit confused where I have to wire at least a barometer. Can someone help me?

You've got 5 UARTs to play with on the GEPRC SPAN F722-BT HD V2 FC. Assuming you purchased the BNF version of the GEPRC Mark5 HD O3, it comes from the factory with the O3 Air Unit connected to either UART1 or UART4, and the receiver connected to UART3. Unless you've already used UART2 and UART5 for something, you can connect the main communication wires of the GPS module to one of those two spare UARTs. If you're using Betaflight then don't bother wiring the compass SCL and SDA connections because a magnetometer is effectively useless under Betaflight and will cause more problems than benefits, with the potential for a flyaway.

Thank you for response! Yes, I bought BNF Mark5. Corresponding to FC manual, DJI O3 unit uses UART1 and RX2 for SBUS. I have no idea where UART4 pads are located on board and not count on them. So, both of those connections SCL and SDA are related to compass, correct? And if i leave them unplugged i will lose only magnetometer but barometer will work, right?

(26-Jul-2023, 05:40 PM)SnowLeopardFPV Wrote: A compass is pretty much useless in Betaflight unless all you want is a visual indicator in the OSD for the compass direction you are heading, but unless you put the module up high well away from the quad electronics and mount it at the right angle for level orientation when flying forwards, in most cases it won't give you a reliable or correct reading, and if it gets used for GPS Rescue with an incorrect reading you risk a flyaway.

Unless you have a specific use case for a compass on your quad then I would either abandon the idea entirely and just leave the compass SDA and SCL connections disconnected, or consider using INAV instead of Betaflight.

For those who aren't aware, Betaflight will figure out heading after about 3 seconds of flying in a straight line. Then the accelerometer keeps track of it.

(15-Oct-2023, 04:51 PM)helgi Wrote: Yes, I bought BNF Mark5. Corresponding to FC manual, DJI O3 unit uses UART1 and RX2 for SBUS. I have no idea where UART4 pads are located on board and not count on them. So, both of those connections SCL and SDA are related to compass, correct? And if i leave them unplugged i will lose only magnetometer but barometer will work, right?

Use the UART5 pads for the GPS module. Those are on the top side of the board on the opposite edge from the USB-C port. Just connect the 5V, GND, TX, and RX to the FC. Leave the SCL and SDA pads disconnected. The GPS will still work. You just won't get any compass (magnetometer) functionality. I recommend that you also switch the Magnetometer OFF in the Configuration tab so the MCU doesn't waste any CPU processing time trying to look for it.

(26-Jul-2023, 03:51 PM)sdtrent Wrote: I ordered a GEP-M10-DQ GPS module from GEPRC and the pinout diagram shows that it needs connections to the SDA and SLC pins on my flight controller. The controller that I have is a GEP-F722-45A AIO V2 (Cinebot 30) and I don't see how/anywhere to connect the SDA and SCL pins on the flight controller. Where are these pins located, or does my flight controller not support these connections?

Thanks in advance.

GPS Module
Flight Controller

In similar fashion to the OP, I have the GEP-M10-DQ GPS Module and am trying to figure out which ports are available on my GEP-F722-45A AIO V2 FC.  But my the drone is the Cinelog35 v2 with DJI and ELRS.

It seems like mine is configured to use T2/R2, T5/R5 for the DJI Air Unit (left side, twisted wires go to the Air Unit) and T4/R4 (top) for the receiver, but I'm new to this so I'm just not sure. Can someone please help me confirm that I could use T3/R3 for GPS and T1/R1 for the barometer/compass?



Another newb question - does it matter which (of the available) pads I use for 5V and GND?

Finally, would I just have to enable the ports in BetaFlight (I'm on 4.4.2) and configure?

Thanks!