nRF52840 USB PHY feedback signal what power source is connected

RE: nRF52840 USB PHY feedback signal what power source is connected

Jared — Wed, 20 May 2020 12:40:23 GMT

Hi,

I'm sorry for the misunderstanding. I was a bit too quick on the reply. Anyways, to answer your question:

The USBD peripheral is USB 2.0 compliant, however it does not have built-in support for the Battery Charging specification. Which means that it will not recognize if it's connected to a CDP or a DCP.

regards

Jared

RE: nRF52840 USB PHY feedback signal what power source is connected

samsam — Tue, 19 May 2020 15:56:14 GMT

Hi Jared,

Sorry, some misunderstanding happens – I’m not interested in what currents nRF52840 consumes from VBUS line, but if nRF52840 could detect what is attached to USB port ( a host or a power adapter) and what power providing capabilities as per USB-IF Battery Charging specification it has?

Short resume on one of the possible ways I found here:

“… device, on seeing VBUS must apply 0.6V on D+ and a current sink on D-, and if it sees 0.6V coming back on D- then it knows that it may draw up to 1.5A. “

Thanks

RE: nRF52840 USB PHY feedback signal what power source is connected

Jared — Tue, 19 May 2020 09:01:17 GMT

Hi,

The current from VBUS supply for the different states are specified in the product specification.

regards

Jared

RE: nRF52840 USB PHY feedback signal what power source is connected

samsam — Tue, 19 May 2020 01:18:58 GMT

Here are Battery Charging v1.2 Spec (and Erratas) from usb.org