Connecting Otii, my laptop and the modem

Hi!

I have bought an Otii and now would like to use to measure power consumption of BG96 modem. I need to connect an external voltage to Otii and in the same time need the Otii to be connected with my laptop to collect data. On the other hand I need to connect my laptop to the modem over USB to send commands. So multiple voltage sources will be connected to the modem, i. 3.3V through the USB ii. another 5 v though the Otii (Otii is connected to both laptop and external source). Should it work, I am mostly scared if I fry the modem.

Hi and welcome to the forum!

I do not completely understand you connection. A block diagram or similar might help.
If you connect the way I guess, then you will get supply from both USB and Otii, but you don’t know how much from USB, so Otii measurement doesn’t say anything.
I might have misunderstood you setup.

Best regards,
Björn

Hi!

I tried to quickly draw the setup, let me know if it is readable.

Best,
Mohammad

Hi Mohammad,

I need to know more about the box Modem to give you an answer.
Hos is Power and micro USB connected in this box.

Best regards,
Björn

Yes the board that houses the modem has both power and micro usb socket.

Sorry, but I need a lot more information to be able to help you out.
How is USB power connected with the other power connector?

Best regards,
Björn

Sorry, which USB?

Here is the adapter https://techship.com/products/pci-express-mini-card-to-usb-adapter-with-external-voltage-and-casing/
With login it is also possible to see the schematic diagram of the internal circuit.