VID and PID for CP2102 - Page 1
Forum section: electronics / projects

author: Abhinav
author_rank: Contributor
timestamp: November 03, 2010, 09:06:23 pm
content: Hi all,We have done a simple project serial port relay control using AT89C2051. Now we need to use it via USB. We are not so good in using USB enabled microcontrollersand also not willing to use ready made USB to RS232 converter cables. After searching on net we found that FTDI and SI labs chips can be used for our purpose. We are liking Si labs CP2102 because it has very low external components. After reading its Datasheet we saw that we can change VID and PID of the chip by changing the data in inbuilt EEPROM of CP2102.Now our problem is we have only 2 pieces of CP2102 they are currently not available at our place. However their prices are quite low ($3.5 per unit). We have seen some people posted that their chip became unusable after changing VID and PID. So if someone has used the VID and PID changing utility available athttp://www.silabs.com/pages/DownloadDoc.aspx?FILEURL=Support%20Documents/Software/an144sw.zip&src=SupportDocLibrarythen please guide what we should not do while changing VID and PID.Thanking you all in anticipation.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 03, 2010, 11:47:57 pm
content: After changing VID/PID you will also need to update the .INF file that comes with the drivers to match the new VID/PID - you won't be able to load drivers unless you do this.

author: Abhinav
author_rank: Contributor
timestamp: November 04, 2010, 08:11:00 pm
content: Hello sir MikeLot of thanks for your reply.Sir we haven't got the .inf file along with the driver there is only a CP210x_VCP_Win2K.exe file. From where we can get this .inf file?Sir all the matter becomes pretty confusing as we found CustomUSBDriverWizard.exe available at ----------http://www.silabs.com/pages/DownloadDoc.aspx?FILEURL=Support%20Documents/Software/AN220SW.zip&src=SupportDocLibraryPlease let me know is this utility is compulsory for our purpose? We just want to show our team name while installing driver and under device manager.If there is any step by step guide available then please give me its link.Please don't get irritated with my silly questions.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 04, 2010, 11:24:39 pm
content: .inf file is used for FTDI drivers - I was assuming Silabs would be similar but maybe not...If silabs support changed VID/PID I'm sure there will be an appnote on their website about it...

author: Unknown
author_rank: Unknown
timestamp: November 05, 2010, 12:11:08 pm
content: There's probably an INF file in the installer package, the custom driver wizard might be the way to change this. Note that VID/PID's are assigned by the USB IF, so you either need to be a member or pay them some money to get one. Silabs may provide PID's to customers, I believe FTDI does.

author: Abhinav
author_rank: Contributor
timestamp: November 06, 2010, 07:56:53 am
content: Hello sir mike and alm,Thanks to both of you for replies.I think if i use custom driver building wizard than inf file will be automatically regenerated. am i right?Finally i think i need to use EEPROM programmer utility and than Custom driver utility with entering same VID and PID in both. please llet me know if i am right.Thank you.