Hardware configuration for 2× M0014 tracking + 1× M0169 PMD ToF + 1× M0024 HiRes

Sarika Sharma

Hello Team, I’m working with a VOXL2 Mini and would like guidance on the correct hardware configuration (cables and ports) for the following camera setup:

Cameras

2× M0014 (OV7251 tracking cameras)
1× M0169 (PMD ToF camera)
1× M0024 (IMX214 high-resolution camera)

Available accessories

M0084 flex cables
M0135 interface board

Could you please confirm the correct physical connection / port mapping for this setup on VOXL2 Mini?

Alex Kushleyev

Hello @Sarika-Sharma ,

Do you have all these cameras already and are asking how to connect them, or are you looking to purchase them?

If you do have the M0169, can you please post the picture of the TOF module and attached adapters that came with it? I just want to make sure I know exactly what you have, since there are several adapter options.

Also, are you open to any updates to the camera selection, as I can make suggestions to use better cameras (both tracking cameras and hires cameras).

Alex

Sarika Sharma

Hello @Alex-Kushleyev
Thank you for getting back to me.

Yes, I already have the above cameras.I am attaching image of the PMD TOF image sensor along with the adapters that were included, so you can confirm exactly which configuration I have.

I would also be very open to your suggestions regarding updates or improvements to the camera selection. Please feel free to recommend better options based on your experience.

Looking forward to your guidance.

Sarika Sharma

@Sarika-Sharma and I also wanna tell you my goal i.e. stable indoor flight without GPS

Alex Kushleyev

@Sarika-Sharma , thanks for the sending the picture of the TOF module.

In terms of connecting all 4 cameras to VOXL2 Mini, there is a lot of flexibility:

both M0084 and M0135 provide two camera ports each
any camera can be connected to any port, but i would probably group two tracking cameras together and then TOF + IMX214
you could choose where to connect the cameras based on the mechanical integration requirements
you can replace M0084 with another M0135 if you do not need a longer extension that M0084 provides
depending on the actual locations of each camera, each camera will have a corresponding camera slot ID (0 through 3) and the camera drivers (sensormodules) will need to be set up correctly, but that is not difficult (we have a helper tools to help with that).
a few notes about the TOF sensor
- it needs external power (not from voxl), so you have to connect the red/black wire that branches off from the APM cable to the dark red power connector on the TOF module assembly
- TOF module is pretty powerful and can potentially overheat if uncooled (with a heat spreader). Please check notes here:
- https://docs.modalai.com/M0169/
- https://docs.modalai.com/M0178/ (this is slightly newer version of the assembly, but should have some applicable info as well)
- to prevent overheating, you can limit maximum "exposure" time for the ToF sensor (that is time the IR emitter is on), please see notes here : https://docs.modalai.com/M0178/#currentpower-consumption (the limit can be set in voxl-camera-server.conf.
- TOF temperature is currently not possible to display anywhere, but if the TOF sensor overheats, the camera server will show an error and the sensor will stop working until until camera server is reset.
- my suggestion is to limit the exposure to 2ms (2000us) instead of maximum 6ms in default mode if you do not have a heat spreader attached.
you can see the heat spreader we now provide with the bundle here (https://www.modalai.com/products/m0178), screenshot below - heat spreader shown in lower left. (note this is the updated adapter configuration for tof sensor, not requiring external power, but we can work with what you already have).

Please make sure as you are plugging in all the interposers / flex cables (M0135 and M0084) and cameras that you line up pin1 locations (marked with a dot), so that you can make the connections properly.

Once you connect everything, you can send a picture of the board, flexes and cameras, i can double check the orientation and provide instructions how to actually set up the camera server for your config.

Alex