AnsweredAssumed Answered

Keyboard Disables When No USB Connection In MC9S08JM60 Demo board

Question asked by Reza Davar on Apr 20, 2010
Latest reply on May 5, 2010 by Reza Davar

Hi All,


Using  MC9S08JM60 chip and DEMOJM Kit, I wrote a software in C# similar to the Freescale GUI for USB application Training, which can be found in the following link:


In the microcontroller code I used the firmware example in the above link and wrote my functions for the keyboards in it.


Now the problem is when I use an external power supply and disconnect the USB cable, the keys are not functioning at all as there are when the USB cable is connected. I have found out that the function in main.c called Check_USBBus_Status() is causing this issue. I don't exactly know how this function helps the keyboards interrupt  to fail. When I remove the function, the USB port won't work even when the connection exists.

It is so appreciated if someone let me know how I am going to fix this problem.


Thanks alot,