[SOLVED] PIC18f4550 USB Not Recognised.

[pcsandhya82]

Hi,

I m trying to interface pic18f4550 USB to PC. I loaded the program for LED Blinking from OLIMEX (attached) and it worked fine. I m using the following circuit from eegeek.(attached). I loaded C:\MCHPFSUSB\fw\_factory_hex\picdemfsusb.hex from microsoft for USB testing.But USB Device is not being recognised by windows. Does it need an extra driver? Windows doesnt even ask for a driver. The LED at pin 19 keeps flashing when I connect USB. 20 MHz clock. Configuration bits attached. ICSP Programming was used.

Could someone tell what could be wrong? How to troubleshoot this? eegeek was offering a nice tutorial but it seems their web site is down.

Thanks in advance.

 

[horace1]

what is the connector X1 ?

This is a circuit I uses for a mini B connector


I would tend to test it with one of Microchip's simple test projects from
**broken link removed**

e.g. HID mouse
C:\Microchip Solutions v2011-10-18\USB\Device - HID - Mouse

it uses a standard mouse driver on the host and moves the mouse around the screen
there is example code for a PICDEM FS USB Demo Board based on PIC18F4550
check you have the oscillator settings correct to get the USB frequency

also have a look at circuit of the PIC18 Starter Kit Users guide on
**broken link removed**

 

[pcsandhya82]

Hi,

I ve already installed MCHPFSUSB Framework. I tested my board with one hex file from that. Didnt work.

 

[Easyrider83]

I loaded C:\MCHPFSUSB\fw\_factory_hex\picdemfsusb.hex from microsoft for USB testing.But USB Device is not being recognised by windows..

You attached only the program for led blinking and it works. Where your USB program?
If the device didn't recognized, possible many causes:
1) Wrong CPU/USB frequency
2) Mixed D+/D- connection
3) Wrong configuration bits
4) Wrong program

Attach your usb program please.

 

[pcsandhya82]

Hi,

I loaded C:\MCHPFSUSB\fw\_factory_hex\picdemfsusb.hex as per this tutorial:https://www.edaboard.com/threads/126795/
I did not bother about the source code, I just started off with a hex file.

When it did not work, I tried this tutorial:Building a PIC18F USB device - WFFwiki
I wired the circuit without the LED and switch on port B, and I could build the code successfully, but device was still not recognised.

code of the second tutorial can be downloaded at the site, but attaching here anyways.

Thanks.

 

[Easyrider83]

Where is hex file?

 

[pcsandhya82]

Hi,

Here is the hex file:

Thanks.

 

[Easyrider83]

Yes, it works. Check your connection. Possible, D+ and D- mixed.

 

[pcsandhya82]

Hi,

It worked too. It was a hardware issue.. Internal short in PCB. The USB data lines were getting shorted.

Thanks a lot for your help.. now I m gonna try and tweak the code.