CX3 with OV9724 Raw8 as grayscale streaming

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user_4665121
Level 2
Level 2

Hello,
I am trying to get mentioned setup (based on Denebola board with OV9724-EAAR board connected with twisted pairs) to work. I've changed VCCIO voltage on my board to 1.8V to directly interface I²C with sensor - and confirmed that it works (this would be also "production" voltage level). Sensor got its reference clock from free running 16MHz oscillator, XSHUT and PWNDB signals are hard wired to high level on sensor board.
For prototyping process I want to use 720p@15fps, so I went for the following sensor setup:

CSI Clock: 200MHz
H-Active: 1280px
H-Blanking: 296px
V-Active: 720 lines
V-blanking: 40 lines
Frame Rate: 15.0
Video support: true
THS-Prepare: 70ns (as set in corresponding sensor register)
THS-Zero: 150ns (also set in sensor)

Then I created profile for CX3 MIPI interface:

REFCLK: 19.2 MHz
Pre Divider Value: 3
PLL OutRange: 125-250M
Multiplier: 125
This gives: 200MHz PLL Out Clock
Output parallel Clock Divider: 4
CSI RX Clock Divider: 4
Fifo Delay: 50 byte

However, no image is being streamed.

Edit1:

After investigation, code never calls CyCx3_ImageSensor_Wakeup() neither CyCx3_ImageSensor_Set_720p_30() routines.

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6 Replies
Hemanth
Moderator
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First like given First question asked 750 replies posted

Hi,

Looks like SET_CUR COMMIT_CONTROL request did not come from Host.

Please check if there were any errors before this request comes from the Host.How many data lanes are you using?

Regards,

Hemanth

Hemanth
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Hello,
I am using single data lane (as sensor has only one). On CX3 side remaining data lanes are shorted to ground (with wire on ESD diode but still). I've seen sensor wakeup call when using linux, however no image was streamed anyways and no errors were reported by (enabled) mipi error thread. I wonder, if there is another descriptor I should use for windows.

Fun fact: when I attached oscilloscope probe to MDP/MDN there are some frame infos, along with errors; without probe there is no output at all

Prod = 0 Cons = 0  Prtl_Sz = 19872 Frm_Cnt = 477 Frm_Sz = 19872 B
3 0 6 0 0 193 9 52 238

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Hemanth
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Moderator
First like given First question asked 750 replies posted

With the cx3 configuration you provided, I think there is an error displayed at fifo delay. Can you please increase the fifo delay to 100 byte and check? currently what is the minimum fifo delay time displayed in your cx3 tool?

Regards,

Hemanth

Hemanth
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Hello, I decided to wire it up properly, i.e. with daughterboard. Due to covid it all took too long, but I can see test patterns, so lets say I got it covered. However still I cannot get any image output - but I believe it is due to the fact, I got only preliminary datasheet without proper application notes (OV will sell you sensors but no docs if you are not going for 10k monthly - and they seem not to understand that there is some research to be done first)

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Hemanth
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First like given First question asked 750 replies posted

Hi,

If the image format is mentioned as RAW8 in the UVC descriptors, then UVC driver will drop the frames as it does not support RAW8 and UVC based player will not display any data.

You can refer to Streaming RAW10 Format Input Data to 16/24-bit Output Format in CX3 MIPI CSI-2 - KBA224387

for the same.

Regards,

Hemanth

Hemanth
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user_4665121
Level 2
Level 2

It was incomplete datasheet. I found proper init sequence (for RAW10 however, which I can live with). Consider this thread closed.

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