Currently running a Tmotor F4 FC and have been unable to get OSD in the goggles. I've read the tutorials on this forum to include freefly-fpv's great work, videos posted by DJI and others on youtube but I cannot seem to get the OSD to work no matter what configuration I do on the FC. Anybody else using this FC and have success? Below is a reference diagram from GetFPV where I bought the FC. I've tried OSD on each UART TX/RX making sure to enable MSP connection and even swapped grey and white in each scenario to rule out accidently swapping wires. Everything else seems to work but would like to know batt volt or a timer at least. The only thing I have not done is upgrade to firmware 4.1 with a development betaflight to enable DJI DHL but from my understanding it should work with standard SBUS protocol. Thanks for any help.

Hello! did you figure out how to connect the Tmotor f4 controller with the air unit? I just bought the same controller and I'm not sure how to connect it , could you share me how you wired it? thanks

fanse5c34158 Posted at 9-14 17:07
Hello! did you figure out how to connect the Tmotor f4 controller with the air unit? I just bought the same controller and I'm not sure how to connect it , could you share me how you wired it? thanks

So turns out I have a bad Air Unit. I had it wired and set up correctly all along. Below is a diagram I made for how to hook it up. The LIGHT gray is the WHITE wire of your 3-in-1 cable. I only used gray to make it easier to see.



Make sure you enable SERIAL RX for UART 5 on the configuration page of betaflight and CONFIGURATION/MSP for UART 3.


Btw just for future reference Tmotor now sells a Tmotor F4 HD flight controller that has a prebuilt wiring harness for the DJI system so no soldering needed to connect to the air unit.

Thanks for the quick reply!! Another doubt, to power the air unit it would be necessary to bridge the two left pads of the CAM bat output to get the 14.8V direct from the battery, right?

Alejandro Iskander Posted at 9-15 06:07
Thanks for the quick reply!!  Another doubt, to power the air unit it would be necessary to bridge the two left pads of the CAM bat output to get the 14.8V direct from the battery, right?

Yes, bridge those two pads. If you're looking at the BAT 5V CAM pads and consider them 1, 2 and 3 from left to right you would bridge pad 1 and 2 together for that 14.8V from a 4S batt.

Charmande Posted at 9-14 19:57
So turns out I have a bad Air Unit. I had it wired and set up correctly all along. Below is a diagram I made for how to hook it up. The LIGHT gray is the WHITE wire of your 3-in-1 cable. I only used gray to make it easier to see.

[view_image]

You mention that you had a bad Air Unit. I am suspecting I am experiencing the same issue as you. I actually wired up mine identically to the image you drew, and only on the very first boot of Betaflight Configurator did I see that the Controller was reading the input. After flashing the firmware and trying all combinations of Serial RX and MSP, I have not been able to get the Flight controller to register input from the DJI Controller. I even tried resoldering the RX/TX from the Air Unit to R4/T4 and setting accordingly in Betaflight Configurator, but still no success. Also tried swapping 'Normal' and 'DJI HDL' in the OSD menu on the goggles. Betaflight Configurator is able to spin the props and get gryo, so I am inclined to think the Flight controller is working.

Is this similar to your experience? Any assistance is greatly appreciated!

helobye Posted at 9-16 13:19
You mention that you had a bad Air Unit. I am suspecting I am experiencing the same issue as you. I actually wired up mine identically to the image you drew, and only on the very first boot of Betaflight Configurator did I see that the Controller was reading the input. After flashing the firmware and trying all combinations of Serial RX and MSP, I have not been able to get the Flight controller to register input from the DJI Controller. I even tried resoldering the RX/TX from the Air Unit to R4/T4 and setting accordingly in Betaflight Configurator, but still no success. Also tried swapping 'Normal' and 'DJI HDL' in the OSD menu on the goggles. Betaflight Configurator is able to spin the props and get gryo, so I am inclined to think the Flight controller is working.

Is this similar to your experience? Any assistance is greatly appreciated!

The issue I'm experiencing is that my Air Unit does not show the drone battery voltage at the bottom right of the screen. It also does not allow me to change PIDs via the in goggle user interface. Your issue sounds a bit different. Below are some suggestions to try and below that is the link to DJI's official tutorials.

1. Rewire back to diagram settings that I posted (YELLOW wire only goes to R5 which is SBUS for that flight controller), make sure your grounds are good, enabled NORMAL in the goggle
2. Make sure the air unit, controller and goggles are activated
3. Resync the air unit to the controller
4. In betaflight make sure you're set to SBUS under Receiver in the Configuration page
5. If you're testing while your drone is connected to the comp make sure you plug in battery to test controller


https://forum.dji.com/forum.php? ... D708%26typeid%3D708

Thanks for sharing

No osd on my unit tried several flight controllers f4 & f7 . Tried all baud rates and different uarts I'm out of ideas. Emailed dji support waiting on a response.

djiuser_5pqw7dGEwOgh Posted at 9-23 08:47
No osd on my unit tried several flight controllers f4 & f7 . Tried all baud rates and different uarts I'm out of ideas. Emailed dji support waiting on a response.

Request an immediate replacement. Hopefully you're still within your 15 day window from when you received the unit. I did the same exact thing and now I'm having to go through their RMA process which is UNBELIEVABLY slow. Do not let them string you around saying they need to "ask an engineer" and pausing a few days to respond, request the replacement ASAP. It's the air unit. I'm seeing more and more of these cases since I've had my issue and mine even caused problems with my FCs. Replace immediately.

Got a replacement DJI FPV air unit today in the mail. Surprising how well things work when you don't have a faulty unit lol. Just thought I'd update this post for anybody that looks at it. Make sure if you're not getting battery voltage, proper range, or ability to change PIDs/controls in the goggles that you first check basic settings and connections but then immediately start a return with DJI. Seems to be a few of these faulty units floating around. Best of luck to all of you and thanks for your inputs.

Hi,

When trying to select the dji hdl setting in the goggle settings the two options normal and dji hdl jump like crazy and I cant pick one of them, any ideas?

I am using the t motor f4 and f55 pro II; my remote controller doesn't connect to the FC, swapped air unit, didn't change anything, FC is connected the right way with R5 being SBUS, and SBUS enabled and ports assigned correctly. Firm wares are updated and all parts are activated and linked properly.

Cheers!

Pls help

Albert90 Posted at 9-27 12:55
Pls help

I replied to you on another post that you had commented on and will continue to post from that forum post to reduce double posting, thank you.

Charmande Posted at 9-23 17:51
Request an immediate replacement. Hopefully you're still within your 15 day window from when you received the unit. I did the same exact thing and now I'm having to go through their RMA process which is UNBELIEVABLY slow. Do not let them string you around saying they need to "ask an engineer" and pausing a few days to respond, request the replacement ASAP. It's the air unit. I'm seeing more and more of these cases since I've had my issue and mine even caused problems with my FCs. Replace immediately.

Just an update, dji refused to replace the air unit as it was over the replacement time period. So it was returned for repair under warrenty. They found no fault. The engineer report said voltage timer and pids were all available.So I've had the unit sent back to me and I'm in the same situation. Which leaves me thinking the goggles have an issue.

djiuser_5pqw7dGEwOgh Posted at 10-11 14:25
Just an update, dji refused to replace the air unit as it was over the replacement time period. So it was returned for repair under warrenty. They found no fault. The engineer report said voltage timer and pids were all available.So I've had the unit sent back to me and I'm in the same situation. Which leaves me thinking the goggles have an issue.

Would you be willing to share your exact setup perhaps with screenshots and pictures of your betaflight configuration, and Flight Controller wiring? Just to double check to ensure we're not skipping anything basic. Do the goggles display at all? Do you get good video? Is this an on screen display in the goggles just with blank information? Just trying to help troubleshoot.

Charmande Posted at 9-14 19:57
So turns out I have a bad Air Unit. I had it wired and set up correctly all along. Below is a diagram I made for how to hook it up. The LIGHT gray is the WHITE wire of your 3-in-1 cable. I only used gray to make it easier to see.

[view_image]

Can you confirm the T-Motor stack on DJI.com comes with the pre-built wiring harness? I need more info on this please!

ehcropydoc Posted at 10-31 04:36
Can you confirm the T-Motor stack on DJI.com comes with the pre-built wiring harness? I need more info on this please!

I did not purchase from DJI for my stack. I linked the version I bought on GetFPV.com. Ensure that it says T-Motor F4 Stack - HD ... the HD for high definition is your key that it is build for DJI's system with prebuilt harness. That seems to be the trend with a lot of flight controller manufacturer's now, if you want their DJI specific build then buy their HD version. As always read the specifications to be sure but hope you find what you need and safe flying.


https://www.getfpv.com/t-motor-f ... in-1-esc-combo.html

Albert90 Posted at 2019-9-27 12:55
Hi,

When trying to select the dji hdl setting in the goggle settings the two options normal and dji hdl jump like crazy and I cant pick one of them, any ideas?

Hey there. Did you find solution to your issue? I got Tmotor 55A F7 stack for DJI and my remote doesnt move the sticks in the servo set up or in Beta Flight. Please share with your experience.

Hello was wondering if anyone could help me with connecting my dji Rc controller with the Tmotors f4 Rc . I’ve sure I have the right ports on because I wouldn’t be able to see the video on my goggles . Can’t seem to get it working in beta flight. My sbus and uart is set in the configurator.

Di anyone find a solution on this? It is a very old post but I am having exactly the same problem with the T-MOTOR F722 V1.1. I noticed conflicts with the SBUS and Ground so I remove those two wires from the FC. I had to do this because I couldn't connect my ELRS receiver. Now I have the receiver working but I cannot get OSD. I move to another RX3 & TX3 to see if the issue was with the FC but no luck. I am working with Betaflight 4.4.3 and looks like it is a bug. I will try to downgrade the version to see if it works.