Microhard module integration with VOXL2

[Jetson Nano]

@Vinny Thanks for sharing across a detailed response. I'll test the setup and get back in case of any doubts.

[Jetson Nano]

@Vinny I have a doubt. Can I use MH module on a different light weight carrier instead of the once provided by ModalAI and have the UART line connected to VOXL2?

I also looked into this topic also for reference, link

Would this type of configuration work?

[Vinny]

Hi @Jetson-Nano
I think that can work. As long as your UART matches the voltage levels indicated here: https://docs.modalai.com/voxl2-connectors/ Voxl 2 does not know (or care) which carrier board you are using.
However, we cannot speak to the quality of that carrier board and if it can provide you all the features you desire, but we trust you know this already as a seasoned user

[Jetson Nano]

@Vinny Thanks. Also I have another doubt. My main use-case for moving to a different module was considering a scenario in my custom air frame where due to space constraints I can't place the MH module on the J3 port. In this case, I'm planning to power the MH module from ModalAI seperately at the rated voltage from the main power line and for communication with VOXL2, I'm planning to rely on the USB peripherals available on the MH module through 4-pin 4-pin JST Type connector heads.

In simpler words, can I use the MH module without J3 port(i.e. the ground unit which can be connected to Laptop) as air unit on the system as well?

[Vinny]

Hi @Jetson-Nano
If you do not use the J3 from VOXL 2 to power your Microhard that is the "-1" variant, you cannot power peripherals. You'll need to use the -2 variant with the red connector: https://www.modalai.com/collections/modems/products/mdk-m0048-2

VBUS in to the MH is not used for powering downstream USB VBUS ports.

[Jetson Nano]

@Vinny Thanks for reverting. I'm little confused now. So when using "-2" variant with the red connector, can the peripherals be powered?

[Vinny]

Hi @Jetson-Nano
Let me try to clarify to help:
The "-3" Plug in board variant https://www.modalai.com/collections/expansion-board/products/voxl-microhard-modem-usb-hub does this:

• Power to MH Modem, USB Interface, USB Power to Downstream Peripherals, and interfaces all through the J3 interface to VOXL 2

However, the "-2" Standalone Module https://www.modalai.com/collections/modems/products/mdk-m0048-2

• brings only USB over the J7 4-pin USB Interface .
• There is not enough power over that VBUS to power the MH Module and downstream peripherals. That is where the red 2-pin JST J8 comes in... That connector provides power to the MH radio AND power to Downstream USB devices.

So, if you originally had a -1 variant that you plugged into VOXL 2's J3, and you want to remove that interface, you will need to switch over to the -3 hardware variant product.

I think that was the info you were looking for and I hope I clarified that for you.

[Jetson Nano]

@Vinny Thanks a lot for the detailed response. You made it very clear. However, My confusions started as I am planning on flying my system using variant "-2" on VOXL 2 only due to space constraints to use "-3", although "-3" is the ideal choice.
Hence, my last set of doubts are:

1. Can I power MH over VBUS if I am not using any other downstream peripherals? Is it reliable / advisable ?
2. Is there a difference in data transfer rates using "-2" over "-3" ?
3. Can I go ahead and use two of "-2" variants - One for air and one for ground and expect same results as using "-3" for air?

[Jetson Nano]

@Vinny My bad, I guess question 1 is moot. Just realised that MH does not accept power over VBUS.

[Vinny]

Hi @Jetson-Nano
No difference in data rate on any MH board. They are all USB2 rates.

Hope that helped!