Luckfox Forums

Hi Luckfox team,

I am trying to determine whether the Luckfox Pico Mini can detect if power is being supplied through USB-C VBUS or through VSYS/header input.

I searched the forum and found this related thread:

Is there a way to determine if USB-C connected?

In that thread, Luckfox mentioned that USB_VBUSDET is not exposed by default, and that using it on some boards may require jumper wiring.

However, I am specifically asking about the Luckfox Pico Mini schematic net USB_DET_IN.

In the Pico Mini schematic, USB_DET_IN appears in the USB power input section as a resistor divider from USB VBUS:

* R26 = 51 kΩ from VBUS to USB_DET_IN
* R28 = 100 kΩ from USB_DET_IN to GND

This gives approximately 3.3 V on USB_DET_IN when USB VBUS is present.

However, I cannot find where USB_DET_IN is connected elsewhere in the schematic. I do not see it connected to the RV1103/RV1106, PMIC, header pins, ADC, GPIO, or any test point.

Could you please confirm whether USB_DET_IN on the Pico Mini is physically connected to any of the following?

1. The RV1103/RV1106 USB_VBUSDET pin
2. A test point
3. A GPIO or ADC input
4. Another circuit block not clearly shown in the schematic
5. No destination / unused net

If it is connected to the SoC, could you also provide the corresponding pin name and the Linux GPIO / ADC / device-tree node needed to read it?

Goal: Detect in software whether USB-C VBUS is present, so the application can behave differently when running from VSYS/header power without USB connected.

Thanks.

USB_DET_IN is a single internal net that is not connected to any GPIO nor routed to any test point. It was kept as an early reserved design and serves no actual function.