P3P, Gimbal Disconnected, No SD, No Video

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#41
If i tap Ambarella Uart under board using U0_T and U0_R on either of the boards should i get any output on putty ?
 
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#44
View attachment 101900
If I tap Ambarella on advanced board with putty it gives this output not sure it tells us much
Looking at the wiki, there's a partial output which shows your output lacks logs with timestamps in square brackets:
o-gs/dji-firmware-tools

Logs starting with timestamp in squares are probably OS kernel logs - this is how it works for Linux, so it is kind of standard. The OS which should be visible there is ThreadX:
o-gs/dji-firmware-tools

So I think Ambarella bootloader works and displays the above messages, but then it hangs while trying to load the kernel. At least we know that the chip and its RAM as working, only programming in NAND is damaged.

on the pro board there is no output at all.
This means bootloader does not work. Its programming may be damaged, or one of the chips does not work at all.
 
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#45
So I need to work out how to program ambarella nand while it’s onboard if possible. So find the wiki on the a7 and hope the a9 is similar.
 
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#46
So I need to work out how to program ambarella nand while it’s onboard if possible. So find the wiki on the a7 and hope the a9 is similar.
Yep. What I was able to find is only:
A7L / A7L(M) RM: System Hardware
But there's also:
A7L Chip Datasheet
A7L Hardware Programming Reference Manual
A7L RM: Firmware and System Boot


For A9SE - I don't even know names of the documents. But I searched for the over a year ago, so maybe something leaked in the meantime?
The "Firmware and System Boot" document would be a best find.
 
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#47
Yep. What I was able to find is only:
A7L / A7L(M) RM: System Hardware
But there's also:
A7L Chip Datasheet
A7L Hardware Programming Reference Manual
A7L RM: Firmware and System Boot


For A9SE - I don't even know names of the documents. But I searched for the over a year ago, so maybe something leaked in the meantime?
The "Firmware and System Boot" document would be a best find.
This is from RC forum translated from Polish is go pro hacking software going to be a help or is this referring to a different part of the software.

Well, it's a pity that the topic is not mentioned that this is about p3 pro / adv. For the 'standard' version the method is known. Generally, in the moments of inspiration, I am slowly picking something up with this topic; first and foremost, I look at the firmware that is part of the drone. It seems that there are a few basic 'types' of components that are in the firmware package in different versions depending on the version of the hardware: main controller ldr main controller app gimbal battery controller electronic speed control radio transmitter vps camera vps sonar FPGA air camera (and camera encoder) video transcoder MCU (I got the name from some Russian which also played with it) For now, I looked at the camera firmware in more detail (it's the largest one - I thought it was from RC before). This is the firmware for the Ambarella A9SE SoC chip, and therefore the same as in the GoPro Hero4. Firmware contains a posix RTOS system, so there is also a network stack - but I do not know if it is controlled by a transciever in the drone. In any case, GoPro is popular and many people are modifying them, hence there are tools to play with this particular block.
 
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#48
This is from RC forum translated from Polish is go pro hacking software going to be a help or is this referring to a different part of the software.
Most of that is public knowledge now. We have the tools to extract modules:
o-gs/dji-firmware-tools

And descriptions of firmware modules:
o-gs/dji-firmware-tools

Plus specific tools for the Ambarella module (m0100):
o-gs/dji-firmware-tools

But we still don't know how to re-flash the firmware if Ambarella isn't booting.
 
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#49
View attachment 100640 Gimbal diode is off. There is 12v at the test pad as is 5v 3.3v and 1.8v at respective pads. Only failed points are on 3.3v on opposite side of board near sd slot it reads 0v not sure if this is relevant. Flowchart indicates problem with voltage regulators or Ambarella chip itself.Does anyone know if the 3.3v pad on other side should be at 3.3v when powered up. View attachment 100637

On the same track is a component with -3.3v on the left and 0v on the right is that correct or has this failed ?
also in my board there is -3.3V
 
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#50
i want to ask you all, the pad signed with "G" at the top of your pic is a ground or what? Because if i mesure between 3V3VD and G there is not 3.3V but 0,30V, they are the pads for the FAN. Thx
 
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#51
i want to ask you all, the pad signed with "G" at the top of your pic is a ground or what? Because if i mesure between 3V3VD and G there is not 3.3V but 0,30V, they are the pads for the FAN. Thx
Voltage drop .3V is common on some transistors. And the fan is software-controlled.
 
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#52
Voltage drop .3V is common on some transistors. And the fan is software-controlled.
yes sure, fan is controlled.... ok, but where there is printed "G" should not be a ground?
Anyway, i did not explain my problems with Ph3 Pro.... simply i do not have live cam on tablet, i do not see any led green/red on gimbal top board, the fan (of gimbal board) does not work and the SD slot does not work.
I do not know, but i think all theese things not working for the same issue.... and i would like really get the reason why. I measured all the voltages on the gold pad and all of them give me back exsattly the voltages printed on the pcb (12V - 5V-3.3V-18V), i measured also the 4 coils and they are shorted. If i measure the voltage on the Led (+) and a Gnd it measure 3.3V, if i measure the (+) on the SD slot it is 3.3V and also on the Fan pin (+).... so i was thinking a ground was missing..... anyway... i'm confused.
 
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#53
yes sure, fan is controlled.... ok, but where there is printed "G" should not be a ground?
Don't ask me. In sometwisted way it is "almost ground" - full ground should be "GND" after all.

Anyway, i did not explain my problems with Ph3 Pro.... simply i do not have live cam on tablet, i do not see any led green/red on gimbal top board, the fan (of gimbal board) does not work and the SD slot does not work.
So Ambarella is not booting. Ambarella controls the LED and the sd-card.

I measured all the voltages on the gold pad and all of them give me back exsattly the voltages printed on the pcb (12V - 5V-3.3V-18V), i measured also the 4 coils and they are shorted. If i measure the voltage on the Led (+) and a Gnd it measure 3.3V, if i measure the (+) on the SD slot it is 3.3V and also on the Fan pin (+).... so i was thinking a ground was missing..... anyway... i'm confused.
You can try shorting the "g" to ground, that shouldn't hurt.

But probably the cause will be in Ambarella pipeline being damaged - it gets power, but it isn't starting. Read about module m0100 on the Github wiki - that's the Ambarella module.

Ambarella consists of the main SoC, external RAM and external NAND storage. Usually the NAND gets damaged, or simply de-programmed.

But the conclusion is - bad news, we don't have a method of re-programming Ambarella. We don't even have full image of the NAND.
And Ambarella Programing Manual is distributed under NDA - we don't have it.
 
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#54
Don't ask me. In sometwisted way it is "almost ground" - full ground should be "GND" after all.



So Ambarella is not booting. Ambarella controls the LED and the sd-card.



You can try shorting the "g" to ground, that shouldn't hurt.

But probably the cause will be in Ambarella pipeline being damaged - it gets power, but it isthn't starting. Read about module m0100 on the Github wiki - that's the Ambarella module.

Ambarella consists of the main SoC, external RAM and external NAND storage. Usually the NAND gets damaged, or simply de-programmed.

But the conclusion is - bad news, we don't have a method of re-programming Ambarella. We don't even have full image of the NAND.
And Ambarella Programing Manual is distributed under NDA - we don't have it.
i flashed the Nand with u-boot.img and ubl1.img and programming was sussesfully, but without resolve the problems. If Ambarella controls the SD and the led, why also the Fan does not work? Thx for replay
 
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#59
That's sure, but we were talking to flash the NAND, is not plugged to Ambarella?
NANDs, RAMs and buck converters are just auxiliary devices which help the Main Computation Unit work.

You have a computer, right? It's got CPU on a main board. The main board contains chipset, and sockets for additional devices: RAM sticks, disks, and power supply of course.

Here you have exactly the same thing, just smaller. So CPU and chipset are integrated into one SoC, but they still need external RAM and external disk (aka storage), and stable power from buck converters.

On the Ph3 Pro Gimbal Top Board, you have two SoCs of the above mentioned manufacturers. You probably know you can't connect a disk to two computers at the same time, right? Two computers mean two storage devices. And in this implementation NAND chip is the storage.
 
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#60
NANDs, RAMs and buck converters are just auxiliary devices which help the Main Computation Unit work.

You have a computer, right? It's got CPU on a main board. The main board contains chipset, and sockets for additional devices: RAM sticks, disks, and power supply of course.

Here you have exactly the same thing, just smaller. So CPU and chipset are integrated into one SoC, but they still need external RAM and external disk (aka storage), and stable power from buck converters.

On the Ph3 Pro Gimbal Top Board, you have two SoCs of the above mentioned manufacturers. You probably know you can't connect a disk to two computers at the same time, right? Two computers mean two storage devices. And in this implementation NAND chip is the storage.
Sorry, but i do not really think you have to teach me what a computer is.... my first notebook i have since 1990... so, i'm here just to ask things to resolve with my board, i'm not experienced about drones and for that reason i was asking if there is a rapid solution to make my gimbal works again.
 

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