M0173 with 4 AR0144 Tracking cameras

cbay

Hi,

Currently in the process of trying to integrate 4 AR0144 tracking camera's with the M0173 on the VOXL2. I have the camera in Slot 0 working and sending video but the rest are proving difficult. I have all of the sensor modules moved to /usr/lib/camera (all the ones found in /usr/share/modalai/chi-cdk/ar0144, not sure what to do wiht the other ar0144 folders). I am able to see another ar0144 connected to slot 2 when running voxl-camera-server -l but it "does not seem to be alive" when starting the server.

Any support would be helpful, I am on the newest SDK. I currently have them setup to be stereo pairs but don't require them to be used that way and may move them later, the plan is to use them all for VIO.

Cheers
Carson

cbay

Seems like its due to my Kernel Config being 0, instead of 1. I can't seem to find documentation on how to update it to 1.

cbay

@cbay welp, Echo 1 worked, worried was going to brick something but it seemed to work. I think this only allows me to use 3/4 AR0144's so will still need support for the 4th

cbay

@cbay echoing 1 into /sys/module/voxl_platform_mod/parameters doesnt persist, so another method is required

Alex Kushleyev

@cbay , you need to flash the kernel for VOXL2 that supports M0173. It is part of the SDK install (there are only two options). Then the selection will persist.

Regarding running 4 Tracking cameras, it is only possible if you change the i2c slave address of one of the cameras (using a hardware modification to move the "slave ID selection" resistor on the AR0144 camera module. In addition to that, you will need updated camera driver (sensormodule) to use the alternate slave ID for the AR0144 camera.

This has been done in another thread:
https://forum.modalai.com/topic/4491/ar0144-rgb-output-on-voxl2

If you look at M0173 connectors (https://docs.modalai.com/M0173/) you can see which I2C (CCI) bus is used for which connector on M0173. There are only 4 unique CCI buses on VOXL2 and unfortunately with M0173, one of them (CCI3 is used for the TOF camera, which uses another connector). So that is why it is not possible to have 4 cameras with the same slave ID when using M0173 approach.

So here is the CCI bus usage for your use case (C27 + AR0144 instead of IMX412 in M0173 J4 (camera slot 1))

: M0173 J1: AR0144 slot 0 : CCI0
: M0173 J2: AR0144 slot 6 : CCI1
: M0173 J5: AR0144 slot 2 : CCI2
: M0173 J4: AR0144 slot 1 : CCI1 *** this is the one that uses duplicated CCI1 bus, so you need to change it's slave address to avoid conflict with AR0144 in slot 6.
: M0173 J3: Unused or TOF (slot 3) : CCI3

(also this is helpful https://docs.modalai.com/voxl2-connectors/)

My suggestion: since you dont have a hires camera, you can connect all 4 cameras to M0173, basically C27 but instead of hires, you have another AR0144 (in slot 1). You will need the AR0144 driver for slot 1 with alt slave address from here : https://storage.googleapis.com/modalai_public/temp/ar0144/ar0144_drivers_alt_slave_addr_0x20_20250709.zip . And make the resistor change on one of the AR0144 cameras and plug it into slot 1 (J4 on M0173).

If you want to use a hires camera as well, then you can use exactly C27 and add another tracking camera to VOXL2 J8 using an adapter such as M0155 or M0181 (use J2 on M0181 for camera slot 5, since M0181 J1 is for boson only) , or similar.

You will find the following image as well as more details for changing the i2c slave id of AR0144 in the forum post mentioned above. Please do this at your own risk as it will void the warranty, since you would be performing hardware modifications to the camera module.

Alex

cbay

@Alex-Kushleyev

This is awesome thank you! Will attempt this and let you know my results. It looks like in the future we will be moving forward with the M0188 on the mini for 4 tracking, 2 lepton and a boson. Our main focus is getting these 4 tracking working with possibly 2 leptons.

Alex Kushleyev

@cbay , M0188 (with voxl2 mini) would allow you to use 4 tracking without changing the CCI slave address, you just use AR0144 instead of Hires Sensor ID3:

https://docs.modalai.com/M0188/

And, you could either use a hires camera in ID1 or another (5th) AR0144 with alt slave address.

By the way, Tracking Sensor ID8 on M0188 is untested and is not available.

Alex

Alex Kushleyev

One last detail,

I will need to check for you whether the M0173 (ID1) and M0188 (ID1 , ID3) have the sync line connected to corresponding coax ports. Worst case scenario you may need to add a 0402 0 ohm resistor (or use unsync'ed AR0144 driver).

I will get back to you about that. If i dont get back to you before you test, you can just use the unsync'ed driver for the camera with alt slave (instead of combo/fsin, use just ..sensormodule.ar0144_0x20_x.bin -- both variants are present in the zip with drivers for alt address)

If you use a combo / fsync variant of the AR0144 driver (both set up the camera to expect a sync signal from the host), but the sync line is not coming through to the camera, you will not get any frames (this is how this particular camera does sync, as it starts the exposure).

Alex

cbay

@Alex-Kushleyev If I dont need to change the CCI to use 4 tracking camera's with M0188, then I am not going to bother to do so with the M0173, I will just run 3 cameras in the meantime.

Am I right to believe that M0188 can allow me to run 4-AR0144, 2-Leptons and 1-Boson+?

Alex Kushleyev

@cbay , M0188 does NOT support a Boson sensor, which has different power requirements and uses different pinout of the same micro coax port type.

M0195 supports 4 cameras + Boson https://docs.modalai.com/M0195/ , but the Boson takes ID2 (CCI2), meaning you would have to put AR0144 cameras on IDs 0,1,3,6 and IDs 1 and 6 would still have a CCI conflict (CCI1). So you would still need the alt slave address for one AR0144.

Boson can only be connected to J2 of M0195, as documented.

Let me check about the dual lepton. It is documented, but i just want to confirm that it works.

Alex