Fixing flash in DM365 chip within Ph3 Pro gimbal

quaddamage · Dec 3, 2017

Here is a success story I wanted to share.

I had a Phantom 3 Pro gimbal which didn't allowed me to see the FPV feed. Photos and movies were recorded on sd-card, there was just no live video - only grey background - in Dji Go.

I explained the details, and the road to fixing the issue, here:

dji-technical-stuff/davinci-replace-nand-dji-phantom-3-gimbal.md at main · quaddama9e/dji-technical-stuff

Technical details and howtos about DJI drones. Contribute to quaddama9e/dji-technical-stuff development by creating an account on GitHub.

github.com

WV. Rootman · Dec 3, 2017

Thanks. Good research. I liked how you deliver the storyline.

quaddamage · Dec 7, 2017

Updated the story (see link in first post) with info on USB connection.

Now I only need the full image to flash.

WV. Rootman · Dec 7, 2017

It sounds like you are really having fun. lol

quaddamage · Dec 18, 2017

Time for a final act of the story.

The wiki was recently updated with downloads of all firmware partitions for the Gimbal Top board:
Flashing firmware on DaVinci media processors · mefistotelis/phantom-firmware-tools Wiki · GitHub

Based on that, I was able to fix my board. Details:

dji-technical-stuff/davinci-replace-nand-dji-phantom-3-gimbal.md at main · quaddama9e/dji-technical-stuff

Technical details and howtos about DJI drones. Contribute to quaddama9e/dji-technical-stuff development by creating an account on GitHub.

github.com

WV. Rootman · Dec 18, 2017

You put the puzzle together and got a picture. Really good going. You got tenacity.

quaddamage · Dec 18, 2017

Hopefully I also helped other people who might want to try their luck at repair.

If the repair would have failed, I'd probably modify the board to demote it from Ph3 Pro to Ph3 Advanced - it looks like this only requires moving a few resistors, plus updating the software within Ambarella.

2008jiayu · Dec 23, 2017

quaddamage said:
Hopefully I also helped other people who might want to try their luck at repair.

If the repair would have failed, I'd probably modify the board to demote it from Ph3 Pro to Ph3 Advanced - it looks like this only requires moving a few resistors, plus updating the software within Ambarella.

How to do that

2008jiayu · Dec 23, 2017

quaddamage said:
Hopefully I also helped other people who might want to try their luck at repair.

If the repair would have failed, I'd probably modify the board to demote it from Ph3 Pro to Ph3 Advanced - it looks like this only requires moving a few resistors, plus updating the software within Ambarella.

I have been done that way ,but the video delay and the frame is lower as previous,how to solve this problem

quaddamage · Dec 23, 2017

2008jiayu said:
How to do that [modify from Ph3 Pro to Ph3 Advanced]

Look at schematics:
dji-hardware-schematics/phantom_3_pro_gimbal_top_board at master · mefistotelis/dji-hardware-schematics · GitHub

Just use KiCad, not PDFs - PDFs are often outdated there.

2008jiayu said:
I have been done that way ,but the video delay and the frame is lower as previous,how to solve this problem

Details. What you did, what are you using, where are you testing, what tests you did, what is the issue.

2008jiayu · Dec 23, 2017

quaddamage said:
Look at schematics:
dji-hardware-schematics/phantom_3_pro_gimbal_top_board at master · mefistotelis/dji-hardware-schematics · GitHub

Just use KiCad, not PDFs - PDFs are often outdated there.

Details. What you did, what are you using, where are you testing, what tests you did, what is the issue.

2008jiayu · Dec 23, 2017

mefistotelis · GitHub

I replace the nand of dm365 and flash ubl uboot kenerl recovery secret ubi system

PriEgor · Dec 25, 2017

I wanna ask, after replace nand flash live feed was laggy? Like only 8fps

quaddamage · Dec 25, 2017

PriEgor said:
I wanna ask, after replace nand flash live feed was laggy? Like only 8fps

No. No issues.

For laggy live feed, I would blame either radio link or mobile device. It is unlikely that such issue originates at compression.

PriEgor · Dec 25, 2017

quaddamage said:
No. No issues.

For laggy live feed, I would blame either radio link or mobile device. It is unlikely that such issue originates at compression.

Code:

FPGA[190,100,1,0]-1.000000:19000000
hdmi status is 1
ARM Load: 18% Video fps: 8 fps Video bit rate: 1315 kbps PHY Bandwidth: 19000 kbps Time: 00:00:59 Resolution: 1280x720

Looks like DaVinci receive 8fps video from Ambarella. Why? This happened when replace Dm365 nand. The same happen when replace dm365 nand's between working units

quaddamage · Dec 25, 2017

PriEgor said:
Looks like DaVinci receive 8fps video from Ambarella. Why? This happened when replace Dm365 nand. The same happen when replace dm365 nand's between working units

Interesting. I will try to take a look at Ambarella when I'm able. Since we don't have any technical documentation of the chip, I don't know too much about it. I have no idea how this could have happened by change in software.

okstuv · Dec 31, 2017

@quaddamage
I'm attempting to repair the boot image on a p3pro top gimbal board as well. Your coverage of this and narrative has been helpful.

I get this response from the 368_u0 serial pins when booting up (below).
However, I am having trouble getting it into Boot flashing mode, aka to return "BOOT ME," so I can send it the proper boot images via Texas Instrument's flashing utilitity...

I've tried tying:

BT01 to 3.3VD
BT00 to 3.3VD
Boot0 to 3.3VD
BT01 and BT00 to 3.3VD
etc...

to no avail... Thoughts?

Code:

DM36x initialization passed!
UBL Product Vesion : DJI-NOHDMI-WM610-UBL-1.0-rc0(2015-01-13)
Dji UBL Version: 1.51(Jan 13 2015 - 16:42:11)
Booting Catalog Boot Loader
BootMode = NAND
Starting NAND Copy...
Valid magicnum, 0xA1ACED66, found in block 0x00000019.
Valid magicnum, 0xA1ACED66, found in block 0x0000001D.
No valid boot image found!
NAND Boot failed.
Aborting...

quaddamage · Dec 31, 2017

Check with multimeter whether the wires you soldered really provide 3.3V to the BT00/BT01 pins.

If they do, and the chip doesn't enter the boot mode - that would probably mean that the pins are not connected to the chip.

alokbhargava · Dec 31, 2017

I’m impressed with the work quaddamage did. Congrats.

okstuv · Dec 31, 2017

@quaddamage
Thanks for the tip. I checked that both bt00 and bt01 we're getting 3.3v and they were... Darn, guess thateans the pads aren't connected to the pins!

One last follow up: for the serial connection, I should be on the 368_u0_tx/rx pins correct?