Hello Everyone,
I have downlaoded sample code of USB HID of LPC2368 and I am using to test it with LPC2387. But code is not working properly.
LED of USB connect is blink while I am attaching USB that means it connects properly But its not able to transfer data. I don't know what is wrong in my code or I am doing something wrong.
Please if anybody had done this before it please suggest me what is wrong.
Thanks in advance.
Hi Tsuneo
I have download latest firmware from C:\Keil\ARM\Boards\Keil\MCB2300\USBHID. But when I tried to connect my board with pc using USB cable(A-type to B-type)it shows an error that driver for this device is not installed. Its documents say that there is no need for any external driver.
Let me know what is wrong I am doing.
Thanks
> it shows an error that driver for this device is not installed.
Sound like D+/D- connection is swapped at the USB connector.
Run USBView while the device is connected to the PC. If you see this symptom on USBView, D+/D- connection is swapped - The device appears as an Unknown Device on the left connection tree pane - VID/PID (idVendor / idProduct) is read out as 0x0000/0x0000 - Device Bus Speed is Low
USBView output when D+/D- connection is swapped - Unknown device Device Descriptor: bcdUSB: 0x0000 bDeviceClass: 0x00 bDeviceSubClass: 0x00 bDeviceProtocol: 0x00 bMaxPacketSize0: 0x00 (0) idVendor: 0x0000 <---------- idProduct: 0x0000 <---------- bcdDevice: 0x0000 iManufacturer: 0x00 iProduct: 0x00 iSerialNumber: 0x00 bNumConfigurations: 0x00 ConnectionStatus: DeviceFailedEnumeration Current Config Value: 0x00 Device Bus Speed: Low <---------- Device Address: 0x00 Open Pipes: 0
USBView on FTDI site www.ftdichip.com/.../usbview.zip
The original USBView is distributed by MS as a part of WDK (Windows Driver Kit) msdn.microsoft.com/.../gg454513
Tsuneo
Hi Tsuneo,
Thanks for the help. Yes the symptom is same as you said in USBview. But I had check connection of D+ and D- and its perfectly connected with microcontroller's pins. I mean D+ is connected with pin29 which is USB D+ bidirectional line and D- is connected with pin30 which is USB D- bidirectional line. So I think it should not create any problems.
Is there any other way? Regards Dhaval
> Yes the symptom is same as you said in USBview.
The point of above diagnosis is "Device Bus Speed is Low" Do you see exactly this evidence? If so, the D+/D- lines are certainly swapped at the USB connector.
I am confused in this matter. I had checked my connections and D+ line of connector is connected to D+ line of microcontroller and same for D- line.
You said that lines are swapped so I have to change that connection and if I do this means I have to connect D+ line of connector to D- line of controller. But I don't understand how it will work if I make this type of reverse connection..
Let me know the logic behind it.
Thanks & Regards Dhaval
I have swapped connection of D+ and D- but still the problem is same.. I don't know what should be the next step. any suggestion?
Thanks Dhaval
1) Is the 1.5k pull-up resistor connects to the D+ pin (P0.29) of the MCU? 2) Does USBView reports "Device Bus Speed is Full"
"Device Bus Speed is Low" suggests that the pull-up resistor connects to D- line of the PC side - wrong connection. Until above 1) 2) are satisfied, try connection combinations :-)
While you are checking the connections as suggested, maybe you should check the values of the series resistors R43 and R49. You schematic calls for 33 ohm resistor which is correct. But are they really 33 ohm? I had a few boards where the resistors where incorrectly populated with 33K resistors. The symptoms were similiar to what you describe in you posts.
Bradford
Hi
Thanks for help. My hardware connections are perfect but may be I have make mistake in download sample code from keil or may be it is copy paste errors. I have again download the code and its working nicely. Obveiously its my mistake and sorry for your inconvenience.
Anyways thanks for all your time and help. You were very helpful. Thanks a lot. Regards Dhaval