Hello all
I am Raju Kamal, a Student from University of offenburg, Germany. Now I am faceing a problem to implement the USB-CDC protocal by using MAX3420e interface with our Microprocessor. Can any body send me the c source code for MAX3420e for USB-CDC. It will be gratefull from me!!!
Best regards Raju Kamal
First i would like to say sorry because of some miscommunication and some bad posting. Now whatever i have send is my code, some of them i have found from this forum and some from maxim. As well as i also need to change some to compatible with our compiler.
So Now i am faceing a problem for writing by the usb. For my project i need to use the hyperterminal com. for coummincation i am using Docklight Scripting software. the final position is now if i send any data by the docklight or windows hyperterminal, it shows me transfer data but does not show receiving data. If it is still confuse please inform me i will try to explain it more.
my problem is now i can read but cannot write
the final position is now if i send any data by the docklight or windows hyperterminal, it shows me transfer data but does not show receiving data.
The above statements are very confusing to me.
I don't know much about this, but normally, you should use an USB Analyzer to analyze what happens during the USB communication.
A. USB Host to USB device -> OK. USB device to USB Host -> Failed.
B. USB Host to USB device -> Failed. USB device to USB Host -> OK.
Your problem is A or B? How do you know/confirm that, it is OK/Failed?
Did you put a breakpoint at the beginning of the USB ISR to see what happens?
Does anybody get the idea what is the problem?? My communication between PC (host) to usb is ok but USB to PC (host) is not ok. For CDC shall i need to use the endpoint2 for Output? The last function "void USB_writeln2" use for writing. here i use Endpoint2, is it ok? i also check with other Endpoint but its remain same no improvement.
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"A. USB Host to USB device -> OK. USB device to USB Host -> Failed.
Your problem is A or B?" My problem is A. My "USB device to USB host is not ok". I have checked with USB analyzer and found USB Host to USB device is ok but the other direction is not ok!! I have also used some break point for debugging. can you tell me how can do the "bulk transfer". So far i understand there is a interrupt transfer and bulk transfer. i need to know about the bulk transfer. If it is still confuse i can write my testing procedure in details.
I don't know much about USB/USBCDC. And I am not familiar with your MCU and your USB solution (Library/Source Code).
But I think/guess that, for most USBCDC device, the Data Flow for sending data from Device to Host (Bulk-In) is:
1. Host polls Device regularly. 2. The USB ISR of the device handles such a polling. (USB frame interrupt handler) 3. The USB ISR of the device puts data into Bulk-In EP. (USB frame interrupt handler) 4. When Bulk-In EP finishes the data sending, another interrupt triggered. (Interrupt driven data sending) 5. The USB ISR of the device handles the next Bulk-In. (USB Bulk-In interrupt handler) It puts more data into Bulk-In EP. (Go to Step 4)
With the USB Analyzer, did you see some regular IN-Packets? How did you respond to such a IN-Packet?
-> With the USB Analyzer, did you see some regular IN-Packets? How did you respond to such a IN-Packet? <-
The above question is incorrect.
It should be:
With the USB Analyzer, did you see some regular IN-NAKs?
With the USB Analyzer, could you see your Endpoint Descriptor of the Bulk-In EP?
Now i can get the both way communication by changing in the Endpoint descriptor on "bmAttributes". But faceing a new problem: During writing in the usb getting extra constant value. for example: i want to write on usb "12345". then i get "X.2345". This "X." all the time comes and "1" is missing.
This problem i am faceing for anykind of string, Missing first charcter and giving "X." instead of First character.
Did you put a breakpoint at where the program starts to get the string?