Downgrading firmware on P3P from 1.10.9 to 1.7.6

[quaddamage]

Yeah.

For some details, looks like m0900 is the Main Controller Unit on the OFDM board:

P3X OFDM Receiver board · o-gs/dji-firmware-tools Wiki

Tools for handling firmwares of DJI products, with focus on quadcopters. - P3X OFDM Receiver board · o-gs/dji-firmware-tools Wiki

github.com

So my educated guess would be that the MCU sends configuration to transceiver.
The transciever - AD9363 - is listed here:

P3X OFDM Receiver board · o-gs/dji-firmware-tools Wiki

Tools for handling firmwares of DJI products, with focus on quadcopters. - P3X OFDM Receiver board · o-gs/dji-firmware-tools Wiki

github.com

If we follow the link and get its datasheet, there is some info on the attenuation:

And also on how it is set:

So the Python tool must be modifying SPI commands which configure AD9363, by allowing to set the attenuation.

We could even go deeper, checking which registers are responsible for that, and how to set them - that is not directly in the datasheet, but it points to such info:

 

[mj2019]

man , its so complicated!!! i thought itsa parameter like height max, i edit it in note pad then recompile it to a fw then update the p3 (digdat0 method and some of his friends tools on github)!! ill not touch it for nowits beyond my knowledge!!

 

[quaddamage]

i thought itsa parameter like height max, i edit it in note pad then recompile it to a fw then update the p3

What I described above is not how to use it, but how it works inside.
And actually, I skipped the complicated bits.

 

[mj2019]

What I described above is not how to use it, but how it works inside.
And actually, I skipped the complicated bits.

i understand whatu said, actually ur a treasure in this high end technical language, but i need a simple method if any exists to get rid of the attenuation, more power means more robust connection, i dont care for fcc and others no one will check ur power, i will not fly inside an er room or hospital to hurt equipment with my higher few aditional db power i would get,
i need the method of changing this parameter as par digdat0 if that isever possible!!

 

[mj2019]

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if the attenuation factor is a parameter so it is possible to do its mod using same method ?

 

[Grumpy]

Thoughts on roll back. I was thinking back to 1.6 which offers the 32 channel hack. With the controller at 2.4.3. Is that not the best option? I see where some went to 1.5 for the increased TX output... but then I see dont use 1.5 due to known bug. Can someone clarify what would be the ideal FW for the aircraft and SW version for the app? Thank you.

 

[mj2019]

hi every one, hope ur all fine. a new challenge if u like to contribute

Dji smart battery replacement attempt

hi every one, since am along some one else who may think that phantom 3 is still air worthy, and since not a lot of batteries are still available for this craft in market or if any is still there the quality or price maybe a concern so i tried to solve this by using our hobby avalable 4s lipo s...

phantompilots.com

 

[syclone50]

Hello everyone, I am not very computer savvy and was wondering if anyone has made a step by step video of the downgrade process. Obviously seeing someone walk you through it is much easier than reading the steps. Thanks

 

[mj2019]

hi there , still flying the phantom3 se,s pro and adv through 2024
this drone no matter what u invest in newer ones cannot be forgotten, may still fly as sexy as the first days, actually i modded it by digdat0 methods on u tube for increased speed and no altitude restrictions

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..

. i have a question too much out of topic i will post it here hopping some one is still interested in the phantom 3 as i am...
my objective is to remove the drone id of the phantom3 that it sends to dji aeroscope .
using the above method of modding in video the parameters of flight controller of the phantom3 are all able to be edited... but i donot see any parameter mentioning drone id , id, i hope fully can find some one who can help ... which parameter sends out the drone id of the phantom 3





a ward of caution not to get me wrong in terms of my intentions "am not in the US and no regulations for drones are there in my country, i rarely fly out of line of sight only filming nature like cliffs mountains or in nature away from cities, and advice not to be smart and fly drones near airports"

 

[Starbase]

Hi all,

is there any new available about how a downgrade a P3P from v1.11.20 below? The only issue I'm currently having is the warning that because of a replaced battery I have to upgrade my firmware and in changelog i read that DJI suddenly implemented a downgrade-prevention in this latest firmware. I don't like that and would like to try a downgrade.

Some pages previously I read something about "DJI admitted that Vers 1 particularly is vulnerable to failure with forward as well as backward FW change" and I want to ask how I can check if I'm having those problematic vers 1 hard- or firmware. If so I think it would be the safest way to stay on v1.11.20 or?

Thanks in advanced.

 

[quaddamage]

in changelog i read that DJI suddenly implemented a downgrade-prevention in this latest firmware.

They tried to expand the protection, by allowing the app to disable your drone (disallow starting motors) if not upgraded.

Simple software-based downgrade protection was there from the beginning, I think.

More advanced protection - by burning fuses - was not possible in Phantoms because the chips inside don't have efuses yet.

But DJI implemented a backdoor to their protection, and didn't removed that in official releases of the firmware - it's the '*_FW_DEBUG" file.

I want to ask how I can check if I'm having those problematic vers 1 hard- or firmware

Not sure what exactly you've found. FW change is always a risk, on any device and in any direction. It's a process which will brick your device if something goes wrong. And Phantoms consisting of many independent modules, have many possible points of failure, making the process more risky than your typical laptop or smartphone.

Some people recommended to do down one version at a time, to minimize the risk. Though I think it's a bit overkill, at least shifting 1.11 to 1.07 always worked for me directly. Below 1.07 I didn't tried, there were some changes to radio transmission in the versions below and I didn't wanted to risk with that. Maybe if going below 1.07 you should go down by one version.

If you want to increase TX power, it's better to mod 1.07 than to go down to 1.05 (if I remember right 1.05 is the version where transmission setup is buggy and it never switches to CE). You can mod your FW by using "hardcoder" scripts from `dji-firmware-tools` repo.
I remember O-Gs had a 2nd wiki (separate to the github wiki) where they explained the simpler things, such as the modding.

 

[Starbase]

Thanks @quaddamage for your reply. I think I will no longer try to find a suitable way to do the downgrade. Feels a bit too risky. I think I will just flash the latest one again for every new battery I bought nowdays to have it all synced and voilà.

Think it's better to spend my time into other projects like building a new - more open source - bird. Propably based on arudupilot but with DYI FPV parts like the DJI O3 Air Unit maybe. Therefore I will check out other threads or maybe create one to check if other members also sucessfully reused an existing Flame Wheel F450 while using modern parts like flight controller etc..