Downgrading firmware on P3P from 1.10.9 to 1.7.6

Hello,

Can somebody tell me why in my log file, the versions checking start with module 400 ? For any other log files starting with 305,306.
 

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Can somebody tell me why in my log file, the versions checking start with module 400 ?
Order doesn't matter.

And why - because this is how DJI programmed it. The order probably depends on order of responses from modules.
 
I have now succesfully downgraded my bird P3P from 1.11.30 -> 1.11.20 -> 1.10.9. In summer I got ESC error and updated to 1.11.30 and managed to fly again, but now when I tried again the error came back. So with fear I had to try and succeeded to downgrade. Thanks for instructions!
 
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I rolled back from 1.11 to 1.7 too with debug method. Can confirm it is working for me. I'm having the board P01012.09 .
I did it like:
1.11 -> 1.10 + Debug
1.10 -> 1.9 + Debug
1.9 -> 1.8
1.8 -> 1.8 + Debug
1.8 -> 1.7
1.7 -> 1.7 + Debug
The last step was important for me, every version step was fine without a + except for 1.8 -> 1.7. There I had to use again debug method on 1.7 itself otherwise I got a + .

EDIT: I have to say that I did the update from 1.10 to 1.11 within the day the update was released the first time on 06.07.2017. And the downgrade was done within the next two days. I don't know whether DJI modified 1.11 to prevent downgrading. I attached the 1.11 I downloaded at 06:30PM at the release day and which I used to upgrade. LINK
The link is nolonger available, do you still have that same version 1.11.0020 tt you uploaded
 
That debug_fw file trick is key! Had a P3A with 1.11 on it and an RC with 1.9 on it. After a few hours, I now have 1.7.6 on the drone and 1.5.8 on the RC. No more weak controller signal issues! Thanks for documenting this, OP!
 
hello all, hope u are fine ... am posting here instead of opening another thread cause the ingredients of the answer should be around, a friend's p 3A phantom 3 advanced is in my hands, he is asking about downgrading the fw from 1.11.20 , i wonder if the debug technique that applies to p3pro here on the thread applies to p3A ???? i once read that p3A downgrade can be done via forcing downgrade by putting fw just one earlier version on sd turning on p3A while pressing the link button, i wonder if this method is valid tested by users, and i read some where that it succeeds for one downgrade only but if true, why cannt it succeed several times i mean repeating this method every downgrade to earlier fw version?
 
One has to ask, why does he want to downgrade the firmware? I'm running 1.11.20 on my P3A with no problems at all from day one.

My set-up:
Firmware 1.11.20
App 3.1.59
RC 1.9.2
 
its worth to know the method! even if u dont need it. any way i read some 10 pages of the thread without noticing that p3A debug trick work to downgrade, only when i wanted to reply now i realized that one post before my question mentioned yesterday is about p3A o_O :mask: :coldsweat:, so the debug works to downgrade:smirk:
 
Really sorry to revive this thread but thinking about downgrading but have questions.
I am on the latest versions, will downgrading improve my transmission power / range?
How can I identify if my drone is suitable for a downgrade?
Hardware:
Phantom 3 Advanced from 2017
GL300C Controller

Thanks much
 
I am on the latest versions, will downgrading improve my transmission power / range?
GL300C Controller
Unlikely.

If you want to extend your range to max, you should modify the firmware in current version rather than downgrading.
This way you also do less firmware updates, so it's less dangerous (each flashing has a small chance of failing).

There is a tool which allows to modify attenuation values within the binary. These values are used to reduce RF power level to either FCC compliant or CE compliant values.
 
Unlikely.

If you want to extend your range to max, you should modify the firmware in current version rather than downgrading.
This way you also do less firmware updates, so it's less dangerous (each flashing has a small chance of failing).

There is a tool which allows to modify attenuation values within the binary. These values are used to reduce RF power level to either FCC compliant or CE compliant values.
Thanks for your reply, quad.
Regarding the tool, I have seen a github page with various codes but the manual was nonexistent. Would you mind pointing me to a manual where I can modify the signal/switch to FCC mode?
 
the manual was nonexistent. Would you mind pointing me to a manual where I can modify the signal/switch to FCC mode?
There are tests included in the repository - this is the easiest way to learn.

Look at `test_hardcoders_p3x.sh` for the air part, and `test_hardcoders_c1.sh` for the RC part.

I downloaded the required firmware files, and then just executed the scripts, capturing output. Then I used commands from that output to do the same manually.

The tests are doing exactly what you want - extract firmware parameters to JSON, modify that JSON, then put everything back together. You may only want to modify different parameters, and to different values; the rest is the same. Also, you only care for Lightbridge control modules - the tests extract other modules as well.

The extracted JSON files have some basic explanations within, ie:
Code:
    {
        "index" : 4,
        "description" : "Transceiver attenuation value for board type 0 with Artosyn chip, change by 1 means 1 dBm",
        "minValue" : 0,
        "maxValue" : 255,
        "defaultValue" : 6,
        "setValue" : 0,
        "name" : "og_hardcoded.lightbridge_stm32.board_ar0_attenuation_tx1_fcc"
    },

My remedy to not knowing which board type I have, was just to adjust the parameters for every board.

For downloading firmwares - nowadays people use DankDroneDownloader, another project on Github.
 
There are tests included in the repository - this is the easiest way to learn.

Look at `test_hardcoders_p3x.sh` for the air part, and `test_hardcoders_c1.sh` for the RC part.

I downloaded the required firmware files, and then just executed the scripts, capturing output. Then I used commands from that output to do the same manually.

The tests are doing exactly what you want - extract firmware parameters to JSON, modify that JSON, then put everything back together. You may only want to modify different parameters, and to different values; the rest is the same. Also, you only care for Lightbridge control modules - the tests extract other modules as well.

The extracted JSON files have some basic explanations within, ie:
Code:
    {
        "index" : 4,
        "description" : "Transceiver attenuation value for board type 0 with Artosyn chip, change by 1 means 1 dBm",
        "minValue" : 0,
        "maxValue" : 255,
        "defaultValue" : 6,
        "setValue" : 0,
        "name" : "og_hardcoded.lightbridge_stm32.board_ar0_attenuation_tx1_fcc"
    },

My remedy to not knowing which board type I have, was just to adjust the parameters for every board.

For downloading firmwares - nowadays people use DankDroneDownloader, another project on Github.
hi, i used the digdat0 method to modify my phantom3p height limit , as i own two p3p i notice one performs much more in terms of range, now it seems i need to modify thisattenuation parameter, first is there a thread or video or link to explain the values?? should the default be 255 for maxtransmission???
 

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