Content originally posted in LPCWare by kpa on Fri Mar 02 08:22:37 MST 2012 Hello all,
I have ported the DualVirtualSerial example to my LPCxpresso LPC11U14. When I connect my board to a computer (RunningLinux) I could see that two new tty are detected and /dev/ttyACM0 and /dev/ttyACM1 are automatically added.
When I try top open them using a terminal (like picocom) I am not able to communicate with the board. On the second port the board should echo every received data. And port one I have replaced the original CheckJoystickMovement()by a function that send a constant string.
Content originally posted in LPCWare by kpa on Wed May 09 06:21:48 MST 2012 I am facing the same problem on LPC11U24xx. Any patch or clean solution is available ?
Content originally posted in LPCWare by smoorby on Thu Apr 19 23:25:08 MST 2012 Hi, this will work but I'm wondering about the use of globals for usb_data_buffer_index and usb_data_buffer_count. In a full usb serial application the data can only be consumed at the UART line rate. Isn't it possible that another USB transfer may complete and overwrite these globals before the first buffer is finished with? Why not do away with the globals and access the data through the currently selected (and retired) DMA descriptor.
Content originally posted in LPCWare by vu on Thu Apr 19 20:10:40 MST 2012 You can try these steps :
1. In Endpoint_LPC17xx.h you can see function Endpoint_BytesInEndpoint(), replace " return (dmaDescriptor[ endpointhandle[endpointselected] ].PresentCount)" with " return usb_data_buffer_size ".
2. And in Endpoint_LPC17xx.c with function DMAEndTransferISR(), you add " usb_data_buffer_size = dmaDescriptor[PhyEP].PresentCount " for OUT Endpoint.
Content originally posted in LPCWare by smoorby on Wed Apr 18 05:36:42 MST 2012 Have looked at the code and think I can see the problem. In the function CDC_Device_ReceiveByte(), whether a byte is read is determined by Endpoint_BytesInEndpoint() which accesses the PresentCount field of the DMA descriptor. The function Endpoint_Read_8() consumes the byte by
usb_data_buffer_index++; usb_data_buffer_size--;
However, this has no effect on what is returned by Endpoint_BytesInEndpoint() as PresentCount in the DMA descriptor is not modified.
I see usb_data_buffer_size is new to v0.94. Doesn't seem to be used consistently. This is related to the "Endpoint_Read_Stream_LE()" topic in this forum.
Content originally posted in LPCWare by smoorby on Wed Apr 18 04:59:30 MST 2012 Hi all,
I have a similar problem with "Example_VirtualSerialDevice". I'm trying to get this as a working example before I try with MIDI device class. It builds without problems configured for LPC17XX / LPCXpressoRevB. It connects and enumerates as a serial device /dev/ttyACM0. I can open this device ok with minicom and then send a single character 'a'. What I get echoed back appears to be an infinite supply of 'a's. Using the LPCXpresso debugger I see CDC_Device_BytesReceived() always returns something > 0 after the first 'a' is received.
Content originally posted in LPCWare by kpa on Wed Apr 04 00:46:41 MST 2012 Ok thanks for your help. There is no check or warning about this. It could be a nice addition.
Content originally posted in LPCWare by kpa on Tue Apr 03 02:02:16 MST 2012 Ok I have tried the DualVirtualSerialDevice demo on myLPCExpresso LPC11U14 with the nxpUSBlib 0.93 The edited sources are attached.
The first VirtualCom work nicely, the second one is visible on my system (ubuntu 11.04), I can open it but it doesn't work when writing or reading from it...
Content originally posted in LPCWare by kpa on Tue Apr 03 01:13:48 MST 2012 Good idea, that was the problem. I have set the CPU only for the Example...
I will now make a try with the DualVirtualSerial example
Content originally posted in LPCWare by kpa on Mon Apr 02 06:55:02 MST 2012 Hello,
I have tested the Example_VirtualSerial on my LPCExpresso LPC11U14 and it doesn't work. When I start the program it jump to the HardFault_Handler. I have executed in step-by-step and it's seems that the issue come from the line "USB_IsInitialized = true;" in the USB_Init() function (line 38 from USBController_LPC.h).
