I need to write a custom USB controller to communicate with a PC. Over the USB we will perform firmware upgrades, upload new operating parameters, download device performance data, etc. The PC side will use WinUSB mechanism to manage the USB device. I need to implement the USB control using a single interface with 2 bulf transfer endpoints, input and output. Have experimented with the USB CDC device example that came with the Keil toolset. I was thinking of taking that example and modify the descriptors and remove any unneeded logic that implemeted the CDC device and add what I need for my project.
Does this seem like a reasonebly place to start? For example, are the handling of the control endpoint esentially the same regardless of device class type?
Not sending the 0 length packet was indeed the problem. By the way my last post was misleading, I never attempt to send more than 64 bytes, larger packets are first broken up to smaller (max 64 bytes) packets and sent individually.
Thanks again for your repsonse.