topic nxpUSBLIB: OTG socket not powered in host mode in LPC Microcontrollers

nxpUSBLIB: OTG socket not powered in host mode

lpcware — Wed, 15 Jun 2016 16:44:31 GMT

Content originally posted in LPCWare by dima2611 on Fri Feb 24 06:11:22 MST 2012
Hi there,

I try the example of MassStorageHost with LPC4350 (board LPC-4350-DB1). I use a "A-Socket to mini-B-plug" cable. I connected pins #4 and #5 to make it look like "mini-A". So, USB0_ID is connected to GND.

I miss the point where in the software the VBUS is switched on. Currently, I have no power there, so an attached device cannot be detected.

No VBUS power => no call of USB0_IRQHandler() => no checking for EHC_USBSTS_PortChangeDetect.. etc.

There are a couple of calls which can be thought of as if they could manage VBUS:
(located in Drivers/USB/Core/LPC/Host_LPC.c)

- USB_Host_VBUS_Manual_Off
- USB_OTGPAD_On
- USB_Host_VBUS_Auto_Enable
- USB_Host_VBUS_Auto_On

But... 1st: they are empty (see macros in ..../Host_LPC.h) 2nd: they are intended to be called in
Host_LPC.c: USB_Host_ProcessNextHostState: HOST_State_Powered which is set through
HcdIrqHandler => PortStatusChangeIsr => USB_Host_Enumerate

But as I said HcdIrqHandler does nothing because unpowered USB OTG socket sees no change.

I hope it is only a configuration problem. Please help! :)

/Dima

Re: nxpUSBLIB: OTG socket not powered in host mode

lpcware — Wed, 15 Jun 2016 16:44:32 GMT

Content originally posted in LPCWare by dima2611 on Sat Feb 25 12:59:02 MST 2012
Hi all,

this new LPC-4350-DB1 board has no power supply for VBUS line which could deliver 5VDC for the device when enabled by HI at usb0_PWR_EN pin. Since I only wanted a host, I supplied the power directly. The quick-n-dirty workaround can be seen at the attached picture. BEWARE that your external power supply may not exceed 5VDC.

/Dima

Re: nxpUSBLIB: OTG socket not powered in host mode

lpcware — Wed, 15 Jun 2016 16:44:32 GMT

Content originally posted in LPCWare by tuong on Mon Mar 26 20:30:49 MST 2012
Dear Dima2611,

Currently the stack configures P6_3 as USB0_VBUS_EN pin, this pin used to drive 5VDC out on USB connector vbus pin, together with a MOSFET or equal parts, after every initiation has finished.

Your board, LPC-4350-DB1, is designed for USB device only, so there is no 5VDC supply on VBUS. Your workarround is simple but, I think, the best way to use host function in this case.

With best regards,
Tuong Nguyen