topic Re: usb_serial missing data in LPCXpresso IDE

usb_serial missing data

lpcware — Wed, 15 Jun 2016 23:30:34 GMT

Content originally posted in LPCWare by tgiacomelli on Fri Oct 14 02:26:42 MST 2011
Hello,

I have used the sample application RDB1768cmsis2_usbstack and RDB1768cmsis2_usb_serial to send 20000 bytes, however the data transfert fails, I only get part of the data. If add a tempo after each character sent, the transfert works but the speed is very low.

I have attached the file main_serial.c and a small python script used as hyperterminal. I have only replaced in the example the echo function with my function to send 20000 bytes.

I think there is something wrong in the communication protocol. I have also seen time to time that the transfert is almost completed only some chunk of 64byte are missing, then these missing bytes are send with the next data transfert.

Thank you for your help

Re: usb_serial missing data

lpcware — Wed, 15 Jun 2016 23:30:35 GMT

Content originally posted in LPCWare by Tsuneo on Sun Oct 16 13:04:37 MST 2011
Hi tgiacomelli,

Code Red is still based on the old release version of LPCUSB CDC, which applies NAK interrupt. This version didn't yet implement transfer termination on bulk IN by ZLP, and latency timer by SOF, too. I discussed on this issue with Bertrik on this thread,
http://tech.groups.yahoo.com/group/lpc2000/message/23422

His newer version on the sourceforge SVN has revised these problems perfectly.
https://lpcusb.svn.sourceforge.net/svnroot/lpcusb/trunk/target/examples/main_serial.c

I recommend you to replace the CDC code with this new one.

Tsuneo

Re: usb_serial missing data

lpcware — Wed, 15 Jun 2016 23:30:35 GMT

Content originally posted in LPCWare by tgiacomelli on Wed Oct 19 00:42:06 MST 2011
Thank you it has solved the problem.