AR0144 on voxl2 J8? Or alternative 4x AR0144 Config?

[jameskuesel]

Will an AR0144 work on J8? Would probably need a Micro-coax Adapter? Not sure if its one output maps to Lower or Upper.

But couldn't find anything about if J8 would support AR0144. At the very least i was able to configure the camera-server with a AR0144 on both J8 Upper and Lower and it succeeded (although cannot test since i cannot connect the actual sensor).

Is this something that has been tested in the past?

For some context, am trying to see if we can run 4 AR0144s, 1 imx412, and 1 pmd-tof-liow2. Potentially some other sorting of these would work. (Such as putting the imx412 on J8 and another AR0144 on J6. Totally okay if it isn't an officially supported config haha can internally test.

current config with the starling breakout board looks like, looking to add one more AR0144

J6_LOWER_SENSOR="ar0144-fsin-combo"
J6_LOWER_NAME="arone"
J6_LOWER_ROTATE="true"

J6_LOWER_COMBO1_SENSOR="ar0144-fsin-combo"
J6_LOWER_COMBO1_NAME="artwo"
J6_LOWER_COMBO1_ROTATE="false"

J6_UPPER_SENSOR="imx412-fpv"
J6_UPPER_NAME="hires"
J6_UPPER_ROTATE="false"

J7_LOWER_SENSOR="ar0144-fsin"
J7_LOWER_NAME="arthree"
J7_LOWER_ROTATE="true"

J7_UPPER_SENSOR="pmd-tof-liow2"
J7_UPPER_NAME="tof"
J7_UPPER_ROTATE="false"

J8_UPPER_SENSOR=""
J8_UPPER_NAME=""
J8_UPPER_ROTATE="false"

Any help much appreciated, Thanks!

Best,
James

[Alex Kushleyev]

Hi @jameskuesel ,

Please check these threads:

• https://forum.modalai.com/topic/5010/m0173-with-4-ar0144-tracking-cameras
• https://forum.modalai.com/topic/4491/ar0144-rgb-output-on-voxl2

Specifically, look for the post with these details:

OK, I was able to confirm this configuration:

VOXL2
M0173 + 3x AR0144 + 1x IMX412 (C27 config)
M0155 + 1x AR0144 plugged into J8
AR0144 i2c slave id change via resistor
small camera driver modification for new slave id
also verified the synchronization between the 4 AR0144

You will need to switch the CCI slave id of one of the AR0144 to avoid bus conflicts, as described in the posts, otherwise no issues.

Do you need all 4 AR0144 sync'ed to the same sync pulse (as normally is done in our dual AR0144 config) ? Please keep in mind that sync may not make sense if the 4 cameras are using different exposure values -- on AR0144 cameras, the sync pulse triggers Start of Exposure, so center of exposure could still be different in the "sync'ed" cameras if the exposure length is different. We can discuss more.

Alex

[jameskuesel]

Hi @Alex-Kushleyev,

Thanks for the reply.

The 4 AR0144 cameras would be used independently rather than as stereo pairs, so I don't believe strict synchronization is required for my use case. My main goal is to add a 4th AR0144 for an independent tracking/perception task.

As long as the 4th camera can be timestamped accurately and integrated alongside the other tracking cameras, I think that should be sufficient. The resistor swap seems a little tricky, so I might post again if I need help with that.

Thanks!

[Alex Kushleyev]

@jameskuesel ,

I think there is another option which i have not considered before. The first three cameras are the same as above:

: M0173 J1: AR0144 slot 0 : CCI0
: M0173 J2: AR0144 slot 6 : CCI1
: M0173 J5: AR0144 slot 2 : CCI2

Then if we use J8U (which can be done using M0181 - it allows you to connect a Boson sensor to lower slot, and a tracking / hires camera to upper slot). Then the fourth camera would be:

VOXL2 J8: M0181 Upper : AR0144 slot 5 : CCI3

And there are no CCI conflicts.

One issue is that we don't typically sell M0181 by itself (only in a kit). Instead you could use two other options, both of which allow connecting a tracking / hires camera to the upper slot:

• M0194 : https://www.modalai.com/products/m0194/
• M0172: https://docs.modalai.com/M0172/ / https://www.modalai.com/products/mdk-m0172-1-00

The only down side of using M0172 / M0194 instead of M0181 is that the two alternatives do not have a mounting hole that would align with VOXL2 mounting hole, but M0181 does have a tab with a mounting hole for VOXL2 J8, see below. The M0172 and M0194 were really designed as mainly options for VOXL2 mini.