GPS power LED dim

General
1

Hi,

I wired the Quescan AN182 gps module to DakeFPVF405 flight controller.

the power LED is on but dim .

for trouble shooting I used a second DakeFPVF405 flight controller and wired it to that , again same result. dim power led.

Then I wired it to F4V3S Plus flight flight controller with Betaflight software. The same GPS works perfectly fine.

Can anybody suggest any trouble shooting ideas including any mission planner parameters.

I am pretty sure I solder it correctly even used the connector provided on the flight controller , set the recommended parameters on SERIAL1_PROTOCOL.

Thanks

2

I don’t think that the PWR LED on the GPS is controlable by the FC. So if it seems to be dimmed you have a power (connection) problem.

3

I have tried connecting to two different flight controllers boards of the same model.
Cleaned the soldering and resoldered.

Used the jst connector on the dakefpv405. Same dim light even then.

Even used a different flight controller board , different firmware (betaflight)

same gps

Just to eliminate the possibility of bad connection.

4

You only repeated what you already described before.Normally the PWR LED is not controlled by any protocol or any firmware.
So check first the power of the module under the different conditions.

5

Yes, check if there is 5V at the connector. After that, why not test it and see if it works?

6

I have used the connector and the pads as shown here on the wiring diagrams.

F405 Flight Stack / F405 Flight Control / 55A 60A ESC ICM42688 Gyro for RC Drone | eBay UK https://share.google/SPaGYWe9nVZNDfZvo

Mission planner is showing no gps.

7

General picture from the web don’t show your real connections and work.
Also measure the voltage on the GPS module. All information I have at the moment show a power problem

8

Please images of connection with two different fc boards and three different connection.

Screenshot_20260604_205345_Gallery
Screenshot_20260604_205345_Gallery1080Ă—2640 317 KB

9

20260604_205308
20260604_2053081920Ă—2560 656 KB

20260604_204656
20260604_2046561920Ă—2560 721 KB

20260604_205224
20260604_2052241920Ă—2560 748 KB

10

It doesn’t look like the connector is properly seated at the module in any of those photos. Don’t make another reply until you have measured the Vcc voltage as asked.
As far as wiring it’s this:

GPS
GPS375Ă—287 16.7 KB

11

That’s a HIT!

There was hardly 2v coming out from that pad. So I tested another Pad before soldering. Now works perfect.

I am over the moon I got a cheap GPS to work with cheap flight controllers from ebay.

Big Thanks Gentlemen.

12

Here is a pic of the new soldering connection

20260605_042015
20260605_0420151920Ă—2560 715 KB

13

If our 5V pads on the FC is going down to 2V only something is really wrong. Check this again so that you don’t have damaged your FCs

14

Were you always only connected to USB when you were using the 5V pin or did you try with a battery connected? The 4V5 pin will definitely be powered thru USB, the 5V pin probably not. Connect a battery and test it again.

15

The crux of the problem appears to be , if connected via usb then the pads are generating 2v but connected via a battery then the 5v pads are generating 5v . Even the GPS led is nice and bright.

I feel this is unusual behaviour, it is certainly not mentioned in any of the youtube , although they do mention make sure the usb cable is a data cable.

[Also cant load photo of less 5MB to show

]

Regards

Zahid

16

That certainly is weird. If your FC gets 5V from USB, then something is wrong in the power path circuit

17

There is no problem. I have Matek H743 boards with the same behavior and fixed with the same solution. But Matek gives a clue:

4V5

18

This fc

did supply the 5v to the gps , although it was running using betaflight.

19

So what? All manufactures have different power strategies. The problem you had is understood and fixed. Move on with the build.

20

You mean the voltage sag is due to excessive current draw?