09-28-2021, 09:06 AM
(09-28-2021, 07:29 AM)dieselnutjob Wrote: I have been looking at the schematic.
Pin T38 on the RK3566 is labelled USB_OTG0_VBUSDET. It goes to capacitor C1400, R2501, through R2500 and to a "blob" labelled TP2202.
R2501 is 15K to ground.
Pin 10 on the USB2.0 HOST2 connector is labelled VBUS on the connector, goes to C2500 and a "blob" labelled VCC5V0_USB_OTG.
VCC5V0_USB_OTG doesn't seem to go anywhere on the schematic but I think that things work when I plug into the port (like my wireless keyboard dongle thing) so I guess it must really be 5V.
There seems no connection from USB_OTG0_VBUSDET on the SoC to VCC5V0_USB_OTG on the USB port.
I need to know whether USB_OTG0_VBUSDET on the SoC needs to be at 0V or at 5V for it to make it act as an OTG port.
R2501 appears to be not fitted on my board.
Is this why it isn't working as an OTG port?
TP2202 is at 3.3V.
Normally Android devices detect that they are supposed to be in OTG mode when the extra (5th) USB pin (I think called "ID") is shorted to earth by the OTG cable.
My suspicion is that this is what the USB_OTG0_VBUSDET pin on the SoC is for.
If so then the correct answer would be to short it to ground.