RAW-MIPI-SC132M on 1.8V I2C bus

[desperex]

Hello, is it possible to use the camera on device with 1.8V I2C bus?
I've just made a test on Orange Pi 4 LTS with two cameras:

1. Raspberry Pi Camera v2.1 (IMX219), camera is detected OK and registered as a subdevice though it's designed to work on 3.3V I2C bus.
2. Your RAW-MIPI-SC132M is not detected. Is it the issue with camera's I2C logic level or I need to search somewhere else for the cause? In case it's I2C voltage issue will I2C level shifter solve this?

Any may I have camera's electric schematics to discuss it on relevant forum?

[veye_xumm]

@desperex
RAW-MIPI-SC132M do not support 1.8V I2C bus. Raspberry Pi Camera v2.1 (IMX219)
The IMX219 is the same. Due to the circuit below, I think the I2C of the Orange Pi is a 3.3V level too.

For the rk3399 platform, we do not provide a driver for RAW-MIPI-SC132M now.

[desperex]

@veye_xumm that's really strange but IMX219's I2C DOES work just fine with 1.8V I2C bus.
Orange Pi 4 LTS uses 1.8V I2C bus, I did the measuring and here's a pic:

I don't know where you got this screenshot from, here is a link to their schematics - link

So my question was: is I2C level shifter is of any good here? and may I have your cam schematics?

[veye_xumm]

@desperex
I simply found a schematic on the orange pi website and looked at it. What you may see is not the schematic of the board you have.
One thing is for sure, is that our camera module does not support 1.8V I2C level standard.

[desperex]

@veye_xumm That's why I measured SDA and SCL with multimeter.
Anyway it seems you're not going to help me here with I2C schematics of your cam or any other way.

[veye_xumm]

@desperex The i2c pins of the RAW-MIPI-SC132M are directly connected to the master mcu chip.

[desperex]

@veye_xumm So there's no pull-ups on camera's pcb side on I2C rails?
And hey, if you (your company) really intend to support Rockchip SBCs, it's something that I'm going through with all things asked.
BTW Just looked into Orange Pi 5's datasheet and it also uses 1.8V I2C bus for cams.

[veye_xumm]

@desperex
The right side of the picture below shows the external I2C circuit of the RAW-MIPI-SC132M.

We have no plans to connect to the orange pi for now. We are porting our MV and RAW cameras to firefly's ROC-RK3566-PC and ROC-RK3588S-PC, and we have already made an adapter board for them.

[desperex]

@veye_xumm Thanks, just used a PCA9306 level shifter and it works perfectly.
I was also looking at ROC-RK3588S-PC but it's a closed linux source targeting mostly Android with weird file structure, partitioning and mounting approaches so it's a no go.

Thanks!

[veye_xumm]

@desperex The linux of this board is open source. firefly has contact information on the wiki page, and you can get a download link to the material after you purchase it and consult it.