Hi everyone,
I’m currently working with the MB1854 ST Camera module, which uses the Sony IMX335 CMOS sensor. I’ve managed to find the datasheet for this sensor.
At this point, I’ve successfully changed the image resolution from the default 2592x1944 to 256x256 using the window cropping mode. However, I’m currently stuck on how to change the frame rate.
On page 56 of the datasheet, it mentions:
I know the value of V_TTL, but I’m confused about the value of the 1H period. There is no "Operating Mode" table in the datasheet. I did find the Read Drive Mode table, which includes values for the 1H period, but they do not apply to my mode (Window Cropping) and appear to be fixed.
Additionally, there’s no mention of a formula for calculating this value.
Also, this datasheet appears to be version 0.2, which was last updated in 2017. I'm not sure if this is even the latest version. I tried to find a forum specifically for Sony camera sensors but couldn't find one.
Could someone please help clarify this?
I was able to change the frame rate using the following formula I found here.
The formula I used -
frame rate = inclk/(vmax*hmax)
However, I have a few doubts regarding this.
According to the IMX335 datasheet (page 57), we have:
VMAX = 0x08F0 = 2288
HMAX = 0x0226 = 550
INCLK = 74.25 MHz (default value)
frame rate = (74.25 * 10^6)/(2288*550)
= 59.003
But the datasheet mentions a frame rate of 118 fps for this configuration.
My question is:
Where does this factor of 2 discrepancy come from?
Is it due to the internal PLL within the sensor mentioned on Pg 9?
Kindly help.
