topic Re: USB Detach in MQX Software Solutions

USB Detach

jmag99 — Tue, 22 Jul 2014 13:55:05 GMT

I am using the MQX USB device stack. I am wondering if there is a way to force the usb connection to detach and shut down until the user unplugs and re-plugs the USB cable to the device.

Re: USB Detach

CarlosCasillas — Wed, 23 Jul 2014 23:29:27 GMT

Hi,

If you want to reset the USB interface (resulting in a detach event), you could use the following functions (considering the CDC example):

USB_Class_CDC_DeInit --> for de-initialize the USB CDC (disappears from Device Manager).
USB_Class_CDC_Init --> for re-initialize the USB CDC (appears again on Device Manager).

Hope this will be useful for you.

Best regards!

/Carlos

Re: USB Detach

jmag99 — Thu, 24 Jul 2014 18:05:25 GMT

Unfortunately, the HID class does not have the same function. I added one, but it does not do what I needed. Instead, I have put the USB peripheral into standby and controlled the pull-ups manually. Removing the D+ pullup, using the OTGCTL register, causes the device to detach through a software means. It can be recovered by just putting the pull-up control back and re-enabling the peripheral (plus plugging in the cable).