P4 Firmware GL300B Interesting USB fault and weird fix

[Jimmy6616]

I cant quite get my head around this one.

Issue: GL300B with no Go 4 app or Go App comms via the USB port
Tried the app and the cable in another GL300C and all works fine so i know the device and cable are good.
Tried a good working usb module and ribbon cable - Same issue
Tried all the button toggles for reset and blue led trigger - Same issue
Read on the forums a multitude of others with the same issue and no apparent fix

Now the strange , very strage part

I replaced the standard GL300B USB module with Inspire (GL658) USB and HDMI modules I had just as a try - It worked immediatly
The controller connects to Go4 and reports firmware 1.9.2, its now connected to my test P4 and fully functional

If I put the original USB module back into the GL300B I get no device connection, but strangly i get a flashing green led showing firmware mismatch, if i put the same module in my GL300C it works fine

I know on the GL658 you can get a corupt HDMI module which will stop the USB port from working, so my thoughts might be a hardware failure on the main controller motherboard which is now relying on the Inspire modules to do the decoding

Any ideas why

 

[Capt KO]

No clue, but glad you found a solution

 

[Jimmy6616]

Would love to have a root cause as I don’t want to waste a HDMI module

 

[Jimmy6616]

Donnie, did you comment buddy?

 

[Harleydude]

My speculation...

This isn't really a mystery at all, as these different DJI controllers have different hardware architectures. The GL300B is different from the A which is different from the C. Same goes with the Inspire 1 family of controllers. It just happens, by dumb luck, that the Inspire 1 HDMI module works in the GL300B (which is actually good to know!). Both families of controllers have slightly different frequency ranges and transmission strengths and, more importantly, different processors! So that is why not all USB modules are compatible with all controllers.

D

 

[Jimmy6616]

The question still is, is why does the standard usb module not work in the GL300B, or maybe someone replaced it with the wrong item. Have you any idea what model of USB module is standard in a GL300B?

 

[Harleydude]

Donnie, did you comment buddy?

I did. For some reason my comment got separated from the original text. That's weird. I'll delete the superfluous post.

D

 

[Harleydude]

The question still is, is why does the standard usb module not work in the GL300B, or maybe someone replaced it with the wrong item. Have you any idea what model of USB module is standard in a GL300B?

I don't know the specifics...but I DO know that the different controllers have different processors, which are naturally going to have to match the installed USB module. Simply stated, you're just experiencing a hardware mismatch. Just because the plugs physically fit doesn't mean the modules are compatible.

Now if you had experienced this across two controllers of the SAME model, then I agree that that would be weird. But I honestly see nothing strange about incompatibility across different controllers, which are ultimately different platforms.

I do not know which USB modules match which controllers. But I think if you research it there will be different USB modules for different controllers.

I will add that perhaps you were dealing with a firmware mismatch. Are both Phantom controllers on the same firmware version??

D

 

[Jimmy6616]

I will do some digging now Donnie. As ever many thanks

 

[Harleydude]

Doing some research...

It seems the P6C-USB is the correct USB module for all 3 P4 controllers. I have 2 theories on this:

1) I honestly don't trust DJI to not sell slightly different versions of these USB modules.
2) Until you can confirm that both controllers have the same firmware versions, I'm still entertaining the possibility that there may be a firmware mismatch.

D