william
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Posted
9 years ago
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I have a thread in the software which outputs a packet of data every 100ms. This works great if I boot the NXP and the host application. When I disconnect the USB cable I see the host handle the disconnection and null out fields in the UI. However, when I reconnect the cable, I can no longer attach to the USB connection. I have tried pretty much everything I can think of, but cannot make this work. If I build the NXP without the device spewing over the USB, I can re-connect and everything picks back up...
The only thing I could not try was to detect in the firmware if there was a USB connection and in which case turn off the thread which broadcasts. I tried to use the USB_VBUS, but the soft connect is keeping the signal of the VBUS high enough that I never get a firm 0 on the signal. I did place the function into USB_VBUS and tried it as a general I/O, but neither worked. If I could detect the connection was gone it would allow me to delay the thread after a reconnection to allow the handshake messages to get through, but I am guessing the issue is one of bus contention. Any ideas?
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Tyler
DZX Support
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Posted
9 years ago
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When the USB cable is re-connected does the device establish a connection and just no more messages are being sent across? Or does it actually fail to connect (i.e. does the PC software think it is connected?).
If the device is reconnecting, but just not able to send any further messages, I am looking into the variable 'usbTransmitting' in usbport.c. It doesn't appear to be getting reset properly in the event a transmit occurs while disconnected. We will investigate further and keep you posted.
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