3G/4G & LTE Base Hat USB connection and power supply

Good morning,

we are using a Raspberry Pi 3G/4G & LTE Base Hat, together with a Quectel EG25-G module.

We have seen, in the proper documentation section on your website, that there is the possibility to power-up the Base Hat and the Quectel module with an external 5V source.

Given the external 5V power source, if we connect the Base Hat to a Raspberry Pi 4 through the proper USB cable for data communication, where does the Base Hat take the power supply from?

Performing a test of the above case, we’ve seen that the power supply of the Base Hat is eventually taken from the USB connection. Could you please confirm (or not) that?

Would it be possible to “split” the power supply signals from the data communication signals of the USB connection from the Base Hat to Raspberry Pi (realizing a proper USB cable), powering-up the Base Hat through an external source and keeping the whole system working?

Thanks in advance for your replies.

Best regards

Hi @Andrea_Sqy,

Yes, we confirm it.

This can be done by removing the fuse from the HAT, as shown in the following figure.
Once it is removed, the 5V of USB will not power the Base HAT.

image

Hi @ensar,

thanks a lot for your answers, your help has been much appreciated.

Best regards