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RE: USB virtual comm

Chinzei Tsuneo

Reply to a new post on the Read-Only thread,
http://www.keil.com/forum/21035/

Ramesh goud
> am working on IAR evalution board (LPC2148) for USB virtual com. The sample code from keil is not working in this board.

Did you really try it?
I believe the CDC example (Keil\ARM\Boards\Keil\MCB2140\RL\USB\Device\CDC\) works on the IAR board without any change.

Here is the schematics of both boards,

Keil MCB2140
http://www.keil.com/mcb2140/mcb2140-schematics.pdf

IAR LPC2148 Development board
old.iar.com/.../LPC2148-board-schematic.pdf

To run the CDC example,
- Both boards mount a 12MHz crystal
- MCU VBUS pin (P0.23) connects to VBUS pin of the USB connector over resistors.
- DB9 connector on UART1 (COM1 / RS232_1)

The difference is just USB_CONNECT (P0.31) pin. MCB2140 doesn't use USB_CONNECT, but IAR board requires it.
The example code enables USB_CONNECT function in USBD_Init(), usbd_LPC214x.c.

In these observations, I believe the Keil CDC example works on the IAR board as it is.

Tsuneo

Parents
  • 0 in reply to Andy Neil

    Hello, first step as you told that the pin for voltage changed to pin 31.

    then by downloading this hex file, it's recognized the com in device manager of PC. He had given a setup file(driver for host), in that you must match PID&VID of your USB_DeviceDescriptor in usbdesc.c

    He had provided two virtual com ports, u can turn it into single virtual com by changing the value of /* bNumInterfaces */ (0x02) to 0x01.

    It's better to change the class /* bInterfaceClass, */ to USB_DEVICE_CLASS_COMMUNICATIONS

    then it's working fine now,
    in my case my USB detected COM46, COM1(UART0) can communicate each. i.e what ever am sending the data from UARTO, am retriving on COM46(USB Buffer)

    here I noticied that if you want reset the board, first you've disconnect usb com port. then only you have to reset the board, otherwise once again it's asking for the host driver..

    That's all from my end....
    HAPPY NEW YEAR.....:)

Reply
  • 0 in reply to Andy Neil

    Hello, first step as you told that the pin for voltage changed to pin 31.

    then by downloading this hex file, it's recognized the com in device manager of PC. He had given a setup file(driver for host), in that you must match PID&VID of your USB_DeviceDescriptor in usbdesc.c

    He had provided two virtual com ports, u can turn it into single virtual com by changing the value of /* bNumInterfaces */ (0x02) to 0x01.

    It's better to change the class /* bInterfaceClass, */ to USB_DEVICE_CLASS_COMMUNICATIONS

    then it's working fine now,
    in my case my USB detected COM46, COM1(UART0) can communicate each. i.e what ever am sending the data from UARTO, am retriving on COM46(USB Buffer)

    here I noticied that if you want reset the board, first you've disconnect usb com port. then only you have to reset the board, otherwise once again it's asking for the host driver..

    That's all from my end....
    HAPPY NEW YEAR.....:)

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