Arducam Mini 2MP camera module is obsolete the official demo seem not work with the new Arducam Mini 2MP Plus camera

[chanffdavid]

Since the Mini 2MP is obsolete

Via this linkhttps://www.amazon.com/Arducam-Module-Megapixels-Arduino-Mega2560/dp/B012UXNDOY   only can buy Mini-2MP-Plus

The official git source https://github.com/NordicPlayground/nrf52-ble-image-transfer-demo and Jimmy https://github.com/jimmywong2003/nrf52-ble-image-transfer-demo/network fork seem can't normally work with the APP source https://github.com/NordicPlayground/Android-Image-Transfer-Demo 

I already test the Mini-2MP-Plus device with Arduino and confirmed the camera work.

But run the demo whatever official or Jimmy fork the APP after connect have not any image display.

Thanks

Best Regards

David Chan

[ovrebekk]

Hi David

I have heard reports earlier that to make the Mini-2MP-Plus module work it is necessary to comment out the following line of code in the main.c file:

arducam_mini_2mp_fillBuffer(img_data_buffer, 1);

Can you try to make this change and see if it is sufficient?

The older module added a byte at the start of the buffer that needed to be flushed, while the plus module doesn't. 

Best regards
Torbjørn

[chanffdavid]

Hi Torbjørn

 

Jimmy already handle the first byte. We can get the JPEG header (ff d8 ff) normally

But the JPEG end (ff d9) never appear.

And away get the libjpeg error on the Android demo app

Compare Nordic demo and Arducam example the get image handle is difference

Arducam use SPI.transfer(0x00); get the camera image data 

Nordic use arducam_spiReadMulti(buffer, transactionLength);  get the camera image data

 

Base on Arducam example the image is complete have normal header "ff d8 ff" and the end "ff d9"

I guess via  arducam_spiReadMulti(buffer, transactionLength); will corrupt the image data mystery 

Can you help to solve?

[ovrebekk]

Hi David

I don't see why reading multiple bytes over the SPI should be an issue, unless you have a signalling issue between the DK and your sensor. 

Could you try to reduce the SPI frequency, and see if this makes a difference?

To do that just change this line in ArduCAM.c and recompile your code. 

You can try NRF_SPIM_FREQ_1M for instance. 

I will also reach out to Jimmy and hear if he encountered similar issues. 

Best regards
Torbjørn

[chanffdavid]

Hi Torbjørn

Thanks for your great help. 

When change the SPI frequency to NRF_SPIM_FREQ_1M the signal is stable and problem solve.

I think may be is the Dupont line problem.

I will try more freq and connection methods to investigate where the noise source.

Thanks

Best Regards

David Chan

[ovrebekk]

Hi David

Glad to hear you found the issue

If you have very long wires between the board and the sensor then this can be an issue. There might be something you can do on the hardware side to improve it. 

If you are able to run it at 2MHz then it should be quick enough, as the BLE link will have a slower transfer rate than the SPI anyway. 

With the SPI running at 1MHz it might be holding the BLE communication back, if you are connecting to a fast phone (such as the latest Samsung models). 

Best regards
Torbjørn