weirdgyn
Posts: 19
Joined: Thu Oct 24, 2019 10:00 am
Location: Follo (SP), Italy

CM3+ vs RaspiCam V2 issues

Thu May 06, 2021 7:58 am

I'm trying to use two RaspiCam V2 with CM3+ and Computer Module 3+ Development Kit board (original components).
I followed instructions provided in official links:
And then I followed camera setup procedure provided here .
As a first try I focused on single camera procedure, unluckly I immediately stumbled on a first issue:

Image

On this forum I found a matching solution here , but following it I got this:

Image

It seems that camera is not found and moreover that I2C bus is supposed to be on GPIO 2 and 3 while the procedure was asking to connect wires on GPIO 0 and 1. I connected I2C bus wires on GPIO 2 and 3 and made a check over I2C trough the following command:

Code: Select all

sudo i2c-detect -y 1
now it seems that camera is found (If I'm understanding the follwing message correctly):

Image

but even with such wiring I'm not able to complete the camera setup procedure because I always get the first message (first issue picture).

This's the content of config.txt (pretty stock):

Code: Select all

# Enable audio (loads snd_bcm2835)
dtparam=audio=on

[pi4]
# Enable DRM VC4 V3D driver on top of the dispmanx display stack
dtoverlay=vc4-fkms-v3d
max_framebuffers=2

[all]
#dtoverlay=vc4-fkms-v3d
start_x=1
gpu_mem=128
Is there a way to fix this and make RaspiCam work with CM3+ ?

Please note that I'm using two different camera units (both RaspiCam V2) and different sets of cables/adapters but I always got the same error.
Last edited by weirdgyn on Thu May 06, 2021 9:59 am, edited 1 time in total.
bye by[t]e{s}... Weirdgyn!

PhilE
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 3876
Joined: Mon Sep 29, 2014 1:07 pm
Location: Cambridge

Re: CM3+ vs RaspiCam V2 issues

Thu May 06, 2021 8:27 am

You need to follow the official guide here: https://www.raspberrypi.org/documentati ... -camera.md

In particular, you need a custom dt-blob.bin to (at least) set the number of cameras, otherwise the "supported" value will always be zero.

Note also that the firmware camera support uses I2C0 - the GPIO usage is controlled by the dt-blob and varies between models.

weirdgyn
Posts: 19
Joined: Thu Oct 24, 2019 10:00 am
Location: Follo (SP), Italy

Re: CM3+ vs RaspiCam V2 issues

Thu May 06, 2021 10:07 am

Yes I followed the guide you referred in the link (I posted the wrong link on my message) and I got the error I showed up.
When you talk about custom dt-blob.bin you mean I need to get it the way the guide suggest i.e.:

Code: Select all

sudo wget http://goo.gl/U4t12b -O /boot/dt-blob.bin
Or I need to do it in another way? Do I have to change file attributes once downloaded or it is superflous?

Regarding I2C0 and GPIO you mean I cannot change the GPIO ports (0,1 -> 2,3) unless I make a custom dt-blob.bin ?

Thnx.
bye by[t]e{s}... Weirdgyn!

PhilE
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 3876
Joined: Mon Sep 29, 2014 1:07 pm
Location: Cambridge

Re: CM3+ vs RaspiCam V2 issues

Thu May 06, 2021 10:47 am

The wget command looks correct. The blob at that link declares a single camera on GPIOs 0 & 1 using I2C0. If you wanted to use GPIOs 2 & 3 that would require you to change the GPIOs and the interface to I2C1 (I2C0 is not available on 2 & 3). If you do this then you won't be able to (or at least you shouldn't) drive I2C1 from Linux - it will fight with the firmware and the result won't be pretty.

weirdgyn
Posts: 19
Joined: Thu Oct 24, 2019 10:00 am
Location: Follo (SP), Italy

Re: CM3+ vs RaspiCam V2 issues

Thu May 06, 2021 12:49 pm

Yes! Downloading it again made it work maybe we had an error downloading it or I made a typo and the result .bin was invalid .
In our configuration we don't really need to change I2C port settings (that was suggested in one of the forum post I read ) we only need to remap GPIO pins to control the camera because we need to reserve such pins for another application.
bye by[t]e{s}... Weirdgyn!

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