Connecting MSU-M0149-1, MSU-M0107, and VOXL 2 Time of Flight (TOF) Depth Sensor

Moderator

We need to connect the following: Forward Facing MSU-M0149-1, MSU-M0107, and VOXL 2 Time of Flight (TOF) Depth Sensor
Sensor with Adapter PCB and M0177 Starling Flex (Molex 40-pin) and a second TOF Depth Sensor in the Rear of our platform as well facing downward. We seem to not be able to figure out which connector works from the TOF we have (MSU-M0178-1-01) with any of the connectors or adapter we have purchased. Do we need to instead be using the (MSU-M0169-1-01) TOF sensor and PCB? Or is there a way to buy the connector and PCB separately to use with the ones we have?

Moderator

The easiest way to connect an IMX412, AR0144 and TOF would be to follow the Starling 2 architecture found here: https://docs.modalai.com/voxl2-d0014/

To just connect the TOF directly to VOXL 2, the M0172 is likely what you are looking for: https://www.modalai.com/products/mdk-m0172-1-00

QSL

@Moderator So to confirm, we need the M0173 to connect the 3 front sensors then the M0172 for the single rear TOF, what cables would we use that are the longest ones available to then connect to the Voxl2 ports?

Thanks!

QSL

BTW We currently have a hadnful of what seems to be the incorrect adapters listed here:

2x VOXL 2 Mini 40-Pin Connector TOF Adapter (MDK-M0172-1-00)
2x VOXL to VOXL 2 Image Sensor Interposer
2x VOXL 2 Dual Image Sensor Expander
2x Cable 26-pin Micro-coax for Image Sensor Modules

TIA

Alex Kushleyev

@QSL

For connecting the second TOF to VOXL2, you would need to use VOXL2's J8 port because J6 and J7 will be taken up by the M0173 with the three front cameras.

So you need M0172 plugged into J8 and then plug in M0177 + M0171/M0178 interposer + (actual TOF sensor) assembly into M0172. You can also use an extension M0170 instead of M0177 (https://www.modalai.com/products/msu-m0170).

using M0177:

(voxl2 J8) <-> (M0172 J1L) <-> (M0177) <-> (M0171 / M0178) <-> (TOF Module)

using M0170

(voxl2 J8) <-> (M0172 J1L) <-> (M0170) <-> (M0171 / M0178) <-> (TOF Module)

Please keep in mind that M0177 and M0171 / M0178 and TOF module are usually sold as one unit. Also, M0171 and M0178 are identical except for mounting tabs which can be removed from one to make the other.

I hope that helps!

Alex

M0172

M0177

M0171 / M0178

Actual TOF Sensor Module

M0170

QSL

@Idan-Fiksel let me know what we need I can get it.

QSL

@Alex-Kushleyev This absolutely is very helpful. I still have some questions though about your documentation about extending sensors further than these cables allow. It says to contact you guys about potential solutions.

We have a decently large size platform that we really want to understand how to position sensors in optimal locations that are not very close to where the Voxl2 is located. This 70mm Cable will still be too short for us to mount the sensor where we would like to.

Our platform is a y6 that is 7" size propellers. We can use a 170mm coax for the front sensor package but for the rear TOF I am wanting to know how could we get it to have 170-250mm cable length so it can be routed to the best location?

Thank you again!

Alex Kushleyev

@QSL ,

TOF is running at a pretty low MIPI rate (i cant recall exactly what it is), so it is easier to make a longer flex for lower transmission rates. I think that for experimentation, we could try connecting several M0170 back to back, but that would not be recommended for anything other than one-off testing because you would need like 3 of these back-to-back and TOF already has a number of connections / interposers. Daisy chaining several extension cables will contribute to signal and power losses and will make the whole assembly less reliable.

For making a custom flex (a longer version of M0170), let's check with @Vinny :).

Maybe you can get a vendor to make a longer version of the cable based on our design.

Alex

Vinny

Hi @Alex-Kushleyev , @QSL 170-250mm is quite long. I'm not optimistic 250mm can even work, 170 would be risky.
We can offer our design services, but typically what that results in is a MOQ of a specific new item, such as 300-500pcs depending on the complexity (at normal MRSP which for flexes runs ~$50-80 each) and lead times would be ~14-18 weeks.
What we would need is a .dxf outline of your intended design and we can review that for feasibility and interest. If it really is 250mm, I'd prefer to no-bid it. 200mm might be the edge here (we do not have sophisticated Sigrity tools to confirm, so going on experience here).
M0170 is not ideally suited for back-to-back (the connectors are a bit offset from each other so the net result would be weird) but it may prove if 140mm can work + ~10 mm for the connector transition losses.
In situations like this, I encourage the ME/Industrial Design Team to reconsider placement of sensors and main electronics relative to each other. There are just some constraints the electronics cannot meet easily. Sometimes just simply re-prioritizing the system constraints helps solve the spatial/distance problems. To extend past ~180+mm, I would encourage you use an external design firm that knows how to do mipi repeaters and high speed design. We've had one customer successfully do that, but it takes some skill and we could do it ourselves, but we just do not have the design cycles to support it this calendar year.
Hope this helps and let us know what your thoughts are, and if pursuing us for a custom design is an option, we can reach out over email.