Z90 Master with RC5 rear cam sync issue

[navarch]

Hi everyone,


I recently purchased a DDPAI Z90 Master with the RC5 rear camera from Amazon US, and I’m experiencing two issues. Both the dashcam and the RC5 are running the latest firmware.


Issue 1 – Front and rear camera synchronization


The front camera starts recording immediately after the dashcam powers on, but the RC5 rear camera consistently starts recording about 5–6 seconds later.


Because of this:

• Every front and rear video pair is permanently 5–6 seconds out of sync.
• This is not just a timestamp issue. The actual video content is delayed by about 5–6 seconds as well.
• The delay starts when the camera powers on and remains the same throughout all recordings.

I have already tried:

• Updating both devices to the latest firmware.
• Factory reset.
• Reformatting the microSD card.
• Rebooting the camera multiple times.

The problem remains exactly the same.


Issue 2 – Internal storage vs. microSD card


I’m also confused about the storage behavior.


I’m using a SanDisk High Endurance 256GB U3/V30 microSD card, and the camera detects it correctly.


However, the camera still records to the internal eMMC storage.


Is there any option to:

• Record only to the microSD card?
• Disable recording to the internal storage?

I couldn’t find such a setting in the app or the user manual.


My questions

1. Has anyone experienced the 5–6 second synchronization delay between the Z90 Master and the RC5?
2. Is this a known firmware issue or a hardware defect?
3. Is it possible to configure the Z90 Master to record only to the microSD card?

Any help or suggestions would be greatly appreciated.


Thank you.

 

[DDPAI_Official]

Hello,

Regarding issue 1, we suggest connecting the dashcam to the DDPAI app to sync the system, or trying to unplug and firmly reconnect the rear camera cable. This should reslove the problem.

For issue 2, the Z90 Master is working under our D²save dual-storage logic. Regular videos write to the built-in eMMC first and automatically transfer to the MicroSD card once the eMMC is full, while emergency videos are saved only on the eMMC for data safety.

 

[navarch]

Hello,

Regarding issue 1, we suggest connecting the dashcam to the DDPAI app to sync the system, or trying to unplug and firmly reconnect the rear camera cable. This should reslove the problem.

For issue 2, the Z90 Master is working under our D²save dual-storage logic. Regular videos write to the built-in eMMC first and automatically transfer to the MicroSD card once the eMMC is full, while emergency videos are saved only on the eMMC for data safety.

Hello,


Thank you for your reply.


I have already completed the steps you suggested:

• Connected the dashcam to the DDPAI app.
• Updated both the Z90 Master and RC5 to the latest firmware.
• Unplugged and firmly reconnected the RC5 cable.
• Performed a factory reset.
• Verified that my SanDisk High Endurance 256GB U3/V30 microSD card is detected correctly.

Unfortunately, the issue still persists.


However, I discovered an important clue that may help identify the problem.


The synchronization issue only occurs during the very first recording after the dashcam powers on.


When the vehicle starts:

• The front camera starts recording immediately.
• The RC5 rear camera starts recording approximately 5–6 seconds later.
• Because of this, the front and rear recordings remain permanently 5–6 seconds out of sync.

However, if I stop the recording and let it start again (for example, by entering and exiting the Album using the buttons on the dashcam, or through the DDPAI app), both the front and rear cameras start recording at exactly the same time, and the recordings are perfectly synchronized.


This makes me believe that the RC5 itself is working correctly. The problem seems to occur only during the initial startup recording sequence, where the rear camera is initialized or starts recording several seconds later than the front camera.


Could you please confirm whether this is a known firmware issue related to the startup process, or could it indicate a hardware problem with the main unit or the RC5?


Regarding the storage behavior, thank you for explaining the D²Save dual-storage logic. I now understand that this is the intended behavior.


I would appreciate any further assistance regarding the synchronization issue.


Thank you.


Kind regards,

 

[DDPAI_Official]

Hello,


However, I discovered an important clue that may help identify the problem.


The synchronization issue only occurs during the very first recording after the dashcam powers on.


When the vehicle starts:

• The front camera starts recording immediately.
• The RC5 rear camera starts recording approximately 5–6 seconds later.
• Because of this, the front and rear recordings remain permanently 5–6 seconds out of sync.

However, if I stop the recording and let it start again (for example, by entering and exiting the Album using the buttons on the dashcam, or through the DDPAI app), both the front and rear cameras start recording at exactly the same time, and the recordings are perfectly synchronized.


This makes me believe that the RC5 itself is working correctly. The problem seems to occur only during the initial startup recording sequence, where the rear camera is initialized or starts recording several seconds later than the front camera.


Could you please confirm whether this is a known firmware issue related to the startup process, or could it indicate a hardware problem with the main unit or the RC5?


I would appreciate any further assistance regarding the synchronization issue.

Hello,

We are sorry to hear that the issue persists after trying theese steps. Also, thank you for providing such a detailed breakdown of the recording sequence.

We have shared your findings and feedback directly with our product and development team. They will look into this and work on optimizing the camera synchronization in a future firmware update.

 

[navarch]

I’d also like to share some usability feedback about the Z90 Master.


Overall, I think the image quality is excellent, but I believe there are a few areas where the user experience could be improved.


1. Option to record directly to the microSD card


The current D²Save design records normal videos to the internal eMMC first and only transfers them to the microSD card later.


Personally, I would prefer an option to record directly to the microSD card.


For example, if I remove the microSD card to review footage on my computer, the latest recordings are still stored in the internal memory, so I have to connect to the dashcam over Wi-Fi and download them first.


It would be great if users could choose between:

• D²Save mode (current behavior)
• Direct microSD recording

2. Preserve the original recording date when exporting videos


When I download a video to my iPhone, the Photos app uses the download date instead of the original recording date.


As a result, videos appear in the wrong position in my gallery, making it difficult to organize recordings.


It would be much better if the exported file preserved the original recording timestamp.


3. Better file management


Since the camera has both internal storage and a microSD card, it would be helpful to have clearer storage management in the app, such as:

• Where each recording is stored.
• Which files are still on the internal memory.
• Which files have already been transferred to the microSD card.

I believe these improvements would make the Z90 Master much more user-friendly.


Thank you for considering this feedback

 

[DDPAI_Official]

I’d also like to share some usability feedback about the Z90 Master.


Overall, I think the image quality is excellent, but I believe there are a few areas where the user experience could be improved.


1. Option to record directly to the microSD card


The current D²Save design records normal videos to the internal eMMC first and only transfers them to the microSD card later.


Personally, I would prefer an option to record directly to the microSD card.


For example, if I remove the microSD card to review footage on my computer, the latest recordings are still stored in the internal memory, so I have to connect to the dashcam over Wi-Fi and download them first.


It would be great if users could choose between:

• D²Save mode (current behavior)
• Direct microSD recording

2. Preserve the original recording date when exporting videos


When I download a video to my iPhone, the Photos app uses the download date instead of the original recording date.


As a result, videos appear in the wrong position in my gallery, making it difficult to organize recordings.


It would be much better if the exported file preserved the original recording timestamp.


3. Better file management


Since the camera has both internal storage and a microSD card, it would be helpful to have clearer storage management in the app, such as:

• Where each recording is stored.
• Which files are still on the internal memory.
• Which files have already been transferred to the microSD card.

I believe these improvements would make the Z90 Master much more user-friendly.


Thank you for considering this feedback

Hi there,

Thank you very much for taking the time to put together such detailed suggestions on how to improve the overall experience.

Your points regarding the option to record directly to the microSD card, preserving the original recording timestamp when exporting videos, and improving storage management between the internal eMMC and the microSD card are all very practical suggestions. Feedback like this helps us better understand what matters most to our users.

I will share your feedback with our product and R&D teams for evaluation.

Thank you again for your support and for helping us make our dashcams more user-friendly.

 

[navarch]

Hi there,

Thank you very much for taking the time to put together such detailed suggestions on how to improve the overall experience.

Your points regarding the option to record directly to the microSD card, preserving the original recording timestamp when exporting videos, and improving storage management between the internal eMMC and the microSD card are all very practical suggestions. Feedback like this helps us better understand what matters most to our users.

I will share your feedback with our product and R&D teams for evaluation.

Thank you again for your support and for helping us make our dashcams more user-friendly.

I would like to clarify the storage behavior I am experiencing.


I understand your explanation of the D²Save dual-storage logic: regular videos are written to the built-in eMMC first and are supposed to be automatically transferred to the microSD card once the eMMC becomes full.


However, this is not what is happening with my Z90 Master.


The internal eMMC becomes full, and instead of transferring the recordings to the microSD card, the camera simply deletes the older recordings from the internal eMMC and continues recording new videos to the eMMC.


The microSD card remains empty and no regular recordings are transferred to it.


The microSD card is correctly detected by the camera and is a SanDisk High Endurance 256GB U3/V30 card.


Could you please clarify why the recordings are not being transferred to the microSD card when the eMMC becomes full?


Is there any setting that needs to be enabled to activate the eMMC-to-microSD transfer function?


If this is not the expected behavior, could this indicate a problem with the microSD card handling or the Z90 Master’s storage system?


Thank you.

 

[DDPAI_Official]

I would like to clarify the storage behavior I am experiencing.


I understand your explanation of the D²Save dual-storage logic: regular videos are written to the built-in eMMC first and are supposed to be automatically transferred to the microSD card once the eMMC becomes full.


However, this is not what is happening with my Z90 Master.


The internal eMMC becomes full, and instead of transferring the recordings to the microSD card, the camera simply deletes the older recordings from the internal eMMC and continues recording new videos to the eMMC.


The microSD card remains empty and no regular recordings are transferred to it.


The microSD card is correctly detected by the camera and is a SanDisk High Endurance 256GB U3/V30 card.


Could you please clarify why the recordings are not being transferred to the microSD card when the eMMC becomes full?


Is there any setting that needs to be enabled to activate the eMMC-to-microSD transfer function?


If this is not the expected behavior, could this indicate a problem with the microSD card handling or the Z90 Master’s storage system?


Thank you.

Hello,

Thank you for the detailed information.

We suggest trying another microSD card to see if the issue persists.

If the issue also occurs with another card and no recordings are stored on the microSD card, please keep the microSD card inserted and continue using the camera for some time until the eMMC starts overwriting older recordings.

After that, please submit a Feedback through the DDPAI app while keeping the microSD card inserted. This will help our technical team further investigate the issue.