PORTS Forum

Ports and Interfaces => USB => Topic started by: nikhil_jain on March 11, 2011, 05:03:47 am

Title: Circuit for PIC18F4550 firmware
Post by: nikhil_jain on March 11, 2011, 05:03:47 am: The firmware for PIC18F4550 is available on the link http://www.lvr.com/hidpage.htm but this works for PICDEM FS USB Demo Board.

I checked the schematics for this board as made available by Microchip but that is a generic scheme. I want to build my own circuit to test this firmware. Can you please provide me the circuit for my purpose?

Thanks
Title: Re: Circuit for PIC18F4550 firmware
Post by: Jan Axelson on March 11, 2011, 11:40:50 am: I think just about any circuit for this chip that has a USB connection would work.

Jan
Title: Re: Circuit for PIC18F4550 firmware
Post by: nikhil_jain on March 12, 2011, 02:38:56 pm: yes.. but i am looking for an exact circuit to run your firmware.

i have found different circuits and i am confused now which one to use.
There's one simple circuit given on this mikroe's page at last (http://www.mikroe.com/esupport/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=158) which i guess works with their library functions.

another one is on this page (http://pwc.theclarkwebsite.com/PIC18F4550usb.php)

basically no one has explained why they have used specific components (esp. capacitors) at diff pins of pic. shall i just go for any of hese circuits?
Title: Re: Circuit for PIC18F4550 firmware
Post by: Jan Axelson on March 13, 2011, 12:10:08 pm: yes

Jan
Title: Re: Circuit for PIC18F4550 firmware
Post by: nikhil_jain on March 16, 2011, 02:44:50 am: I tried the firmware with the first circuit i mentioned above, but it does not seem to work. If I use the sample library code provided by Mikroelektronika, its working perfectly fine. But not your firmware. The host is not even detecting the device. Please help.
Title: Re: Circuit for PIC18F4550 firmware
Post by: Jan Axelson on March 16, 2011, 10:39:55 am: Take a look at the settings in main.c for the crystal frequency and bootloader and be sure they match what you're using.

Jan