Problems with the USB initialization

wolfen · ‎2007-11-27

Posted on November 28, 2007 at 06:58

ben2 · ‎2007-08-05

Posted on August 06, 2007 at 07:20

Do you have access to a usb bus analyzer ? Is the PC seeing the device inserted ?

Also do you have control of the pull up resistor on the USB line (I cant remember which off hand) On my board I set up all of the end points and configured everything and then enabled the pull up. The PC then configured the address, which is what your while loop is waiting for.

If you are not getting an interrupt it is most likely that the PC is not seeing your device.

Ben

wolfen · ‎2007-08-05

Posted on August 06, 2007 at 07:49

sjo > OK now I see 😉 I'm using Metrowerks CodeWarrior, so I don't use gcc as a compilator... The variable is declared with the u16 type only.

ben_fnr > When I connect the card to the computer, my PC tells me it sees an unknown USB device... Else I don't know anything about this pull-up resistor :-? I need to get some information about this...

I have another question : do I have to connect the interface to get the program working ? I think this may be a silly question, and I have tried before to execute the whole thing with and without the connection... But I have to be fixed 🙂

ben2 · ‎2007-08-05

Posted on August 06, 2007 at 08:02

Yes you will need to connect the USB cable to a PC in order to get the software working. Make sure the STR7 is running before inserting the USB cable.

The pull up resistor is used to indicated to the PC that a device has been inserted. It is possible that you can get away with not having one. Check the USB spec. If you connect the resistor between the USB D line (not sure which one) and a GPIO port you can fool the PC into thinking the USB device has been removed/inserted by pulling the line low or high without having to remove the cable.

Ben

wolfen · ‎2007-08-08

Posted on August 09, 2007 at 08:18

Another question : when I enable the interruptions, instead of staying around the while loop I am not been able to go out, sometimes the program seems to ''crash''. When I stop it during debug, I am into a list of dci instructions or andeq... That means the call of the interruptions is not done in the right place...

What can be the cause of this ? A bad assignation of the memory ? A problem related to the clocks ? If I can avoid the modification of the .s files in ADS, I'll be happy :-]

Seriously, this problem begins to be boring. I have taken the work of someone else, who was able in a few days to make the examples work, and I have not been able yet to do the same thing, I have taken some ''clean'' code from the ST website, and I can't see what is wrong...

[ This message was edited by: Wolfen on 09-08-2007 11:51 ]

lodedeschepper · ‎2007-11-27

Posted on November 28, 2007 at 06:58

Wolfen,

Is this problem already solved? And if so, what was the solution? I have a similar problem.

Best regards,

Louis XIV