I m writing program for USB host Virtual com port(LPC1768). May be this question found silly but this is confusing me.
Im getting frames correctly upto get line coding After that host is not responding to the device.I m continously getting NACK after every IN after get line coding.
Second issue is i can see the comp port in com port list. I installed drivers through inf file. But when i tried to open the comp port it shows "error: unable to open the com port".reasone for this is the code issue or the drivers issue.
I m bit confuse with the flow of frames in the virtual com port. can any one tell me the flow of frames.which will be the next frame after get line coding.what happened when this frame comes in a picture in hardware point of view.
Hiii John
This is for the first time i m looking for USB.I m using nxpUSBlib v0.98 for reference.
www.lpcware.com/.../nxpusblib-v098
U can check the condition in .zip\libraries\LPCUSBLib\Drivers\USB\Class\Device\CDCClassDevice.c line number 47.
When host ask for get line coding device should response host with the settings of com port.This sholud happen right? I tried above code it is working fine but i didnt get these comp port settings anywhere in the program. Actually the program contains lib. We have to go through C files and decode what exactly is happenning.
nxpUSBlib v0.98 is not recommended.
http://www.keil.com/forum/24814/ www.lpcware.com/.../lpc1347-virtual-com-port-questions
Maybe it is designed to not work for LPC1768. If you insist to use NXP Library, try newer version of LPCOpen.
Try this: www.lpcware.com/.../lpcopen-software-development-platform-lpc17xx-packages www.lpcware.com/.../lpcopen
Use this example: \lpcopen_2_10_keil_iar_nxp_lpcxpresso_1769\applications\lpc17xx_40xx\keil_uvision_projects\nxp_lpcxpresso_1769\nxp_lpcxpresso_1769_usbd_lib_examples.uvmpw
thanx john for your help. I m looking for this. Will let u know.
Hi john thanx for number of replies. Today i finished with USB CDC i was mistaken in end point write.That is the main reason i didnt get the answer for get line coding and other silly reasons.Any ways thanx for help. My next work is USB mass storage device(LPC1768 as a mass storage device).If u have already worked on that i need your help.