Getting USB to work on Explorer 16/32 with PIC32MZ2048EFH100 PIM
I have a question on how P1_VBUS is supposed to work on the Explorer 16/32 development board. I'm not an expert on USB, but I have spent a good amount of timing studying the PIC32MZ datasheet and the USB specifications.
I have the USB-A connector working now, but I had to disconnect the USB-C VBUS (cut trace) and wire P1_VBUS at PIM pin 1 directly to J32-1. Details:
1. Cut trace from PIM pin 1 on top side of board. It's the wire near the white triangle pin-1 indicator.
2. Wire a jumper on back side of board from J32 pin 1 to PIM pin 1.
! Note/warning that this also moves P1_VBUS_E over to this new VBUS.
I believe that VBUS has to get to +5V, but I don't find enough details on how VBUS is used inside the PIC32MZ USB module to confirm. I can confirm the bringing it to +5V got the USB bus working for me.
In looking at the Explorer 16/32 schematic (USB-C section) I see that P1_VBUS is connected through a diode to the +3.3V supply. This clamps it at about 3.9V, so I don't see how it can ever get to +5V. There are a lot of options with USB what with legacy plus USB-C plus device/host mode, so there certainly may be circuit details I've missed.
Can anyone shed light on how this should work? Does anyone have the on-board USB working as-is? I understand there is a PicTail USB adapter, but the USB-A port should have everything I need.