How to read unique identifier for each Raspberry Pi IMX477 camera (B0270)?

Raspberry Pi Cameras
1

Hi, I need to read the unique identifier (serial number) for each of my cameras. Is there a way to do that? I’ve got a batch of Raspberry Pi IMX477 cameras, the B0270 model specifically, and I need to tell them apart programmatically. How can we do that?

2

Hey, happy to help. A couple of quick questions so I point you in the right direction:

  1. Roughly how many cameras are in the batch?
  2. Are you running these on Raspberry Pi (libcamera / v4l2) or on a host via USB/UVC?
  3. Do you just need to read an existing unique ID, or do you also want to assign/modify one per camera?

If you can also share the output of v4l2-ctl --list-devices and dmesg | grep -i imx477, that’d help a lot.

3

We have a number of them, not just one. All Raspberry Pi IMX477 (B0270), running on Raspberry Pi boards, so libcamera/v4l2 on the CSI connector, not USB/UVC.

Ideally I want to read a serial number off each one. If reading isn’t possible I’d also consider writing my own so I can track them. Here’s what I get:

$ v4l2-ctl --list-devices
unicam (platform:fe801000.csi):
/dev/video0
/dev/video1
/dev/v4l-subdev2

And a chip id:

$ i2cget -y 10 0x1a 0x0000 w
0x0477

That 0x0477 is the same on every camera I try, so it’s not unique per unit.

4

Right, that 0x0477 is just the sensor ID for the IMX477 itself, not a per-unit serial. There isn’t a factory-programmed unique serial in the sensor registers on the IMX477 modules, so every camera returns the same value.

Can you dump the device tree and see if anything looks unit-specific?

$ dtc -I fs /proc/device-tree | grep -i -E ‘serial|eeprom|camera’
$ cat /proc/device-tree/model

Also, are you on a camera (like the Raspberry Pi Camera Module) or a custom board? Some Arducam boards carry a small EEPROM, but the B0270 typically doesn’t have one.

5

Here’s what I get:

$ cat /proc/device-tree/model
Raspberry Pi 4 Model B Rev 1.4

$ dtc -I fs /proc/device-tree | grep -i -E ‘serial|eeprom|camera’
(nothing relevant)

No EEPROM on the module as far as I can tell. So to confirm — is there really no unique serial stored anywhere on the B0270? If not, I’d like to write my own serial number to each camera so I can distinguish them. Is there a tool to modify the serial number on this camera?

6

Short answer up front: for the B0270 (Raspberry Pi IMX477) we don’t have a tool that can modify the serial number. The tool that lets you read/write the serial number only exists for our UVC cameras. The B0270 is a raw MIPI sensor module on the CSI bus, so it doesn’t expose a serial-number field you can overwrite.

The UVC cameras have a small onboard controller with a configurable serial string (that’s why they show up with distinct serials and why the tool works on them). The B0270 has no such controller — the IMX477 is connected directly to the Pi’s CSI, so there’s nothing to store a per-unit serial in.

That’s why all of your boards return the same 0x0477. I don’t want to send you down a path that won’t work, so I’d rather tell you now that there’s no write tool for this model.

7

Understood, but let me make sure I’m not missing something. Just to be thorough I tried a few things:

  • media-ctl -p -d /dev/media0 — shows the sensor entity but no serial field
  • v4l2-ctl -d /dev/v4l-subdev2 --all — only the usual sensor controls
  • Read a bunch of registers over i2c, all identical across units

All the same on every camera. So there’s genuinely no per-unit ID I can pull, and no way for me to write one. Is that the final answer?

8

Yes, that matches what we see. Summarizing where this lands:

  • The B0270 (Raspberry Pi IMX477) has no factory unique serial number. The only identifier is the shared sensor ID 0x0477, which is identical on every unit.
  • There is no serial-number field exposed over v4l2/i2c on this module, so nothing to read per camera.
  • The tool to modify/assign a serial number exists only for our UVC cameras, not for the B0270. So there’s no supported way for us to write a unique serial onto the B0270 either.
  • Nothing in the device tree or sensor registers lets you distinguish individual B0270 boards.

So unfortunately there’s no tool or method available on our side to read or modify a serial number for the B0270. If your setup needs per-camera identification, you’d have to track it externally (e.g. label each board and map it to a physical port or host), since the camera itself can’t report a unique ID. If you later move to one of our UVC models, the serial read/write tool would work there. Sorry I can’t give you a cleaner answer on this one.