BGS5 USB cold-plug vs hot-plug | Thales IoT Developer Community
September 13, 2016 - 3:05pm, 2291 views
When starting a BGS5 by providing BATT+ and 600ms later an IGNITION pulse while the USB connection to a PC is present (cold-plug), sometimes the BGS5 doesn't enumerate in Windows 7 (unknown device detected and no modem device is in device manager).
If in this situation, we remove the USB connection and restore the USB connection (so hot-plug), the BGS5 always enumerates in Windows 7.
Is there a difference in the USB stack of the BGS5 between cold and hot-plug?
Hello,
Are you sure that when it happens there is no USB connection to the module established? Because if there would be a connection open in Windows the USB ports would be available. In case of re-plugging the cable in such a situation the USB connection could enumerate on some other COM port.
Other thing would be the hardware - could you describe a little bit what hardware you are using especially the USB part?
Regards,
Bartłomiej
Yes I'm sure there is no USB port. I found out by experiments that the 600ms is directly related to this behavior. I changed the 600ms to 290ms (the release notes mention > 285ms) and in this case the device enumerates correctly for at least 200 ***** in a row using cold-plug.
So it appears there isn't only a minimum time but also a undocumented maximum time.
Thank you for this information. Good that it's working. So it seems that it was a hardware problem.
On the other hand as far as I know in the concept board for example the BATT+ line is always connected. Didn't you change anything else in your HW?
Regards,
Bartłomiej
No, we didn't change anything else. The problem must be in the BGS5 bootloader code.