This means that the RS-232 device here is guaranteed to never require any form of RS-232 flow control. So, as written above, is what I'm trying to do here even possible with the standard USB CDC protocol? Which endpoint should the "hold up" command be sent along, and what should it look like? Not looking for the complete answer, just some basic pointers would be greatly appreciated! EDIT: Here's a more concrete version of my question: In this hypothetical situation, we have a 1200 baud device that is fast enough to handle whatever a PC throws at it, because the 1200 baud channel is naturally quite limited, and the device can hypothetically handle each line/character as it comes. Alas, the code I see is vastly simpler in fact there's no ring buffer to speak of at all, and bytes are dropped. Perhaps I was expecting too much, but I was expecting the USB interrupt handlers to notice if the buffers were getting near full, and for them to tell the PC to hold up. Some test in others operational systems like Windows XP SP3 x86 and Windows 7 Ultimate 圆4 and my device works perfectly.Īt the present time, I don’t know if it’s a fail of the operational system that doesn’t permit the USB operation mode changes without reconnect the USB cable or it’s an error occasioned by the Windows 10 driver “usbser.sys”.TL DR: Does the USB CDC protocol support flow control (specifically, the MCU says "hold up", and any writes on the connected PC block)? How does the MCU say "hold up"? I just ran the USB CDC demo for my LPC Expresso LPC11U37H (an ARM cortex M0+ board fwiw), and I tested what happens when the UART's buffers fill up by adding long sleeps in my application code to simulate a complex operation. This problem occurs just in the Windows 10. The problem that is occurring is when my device changes the operation mode (USB Class) from “USB HID Device” to “USB CDC Serial” the computer doesn’t recognize the USB CDC Serial device.
Speed and flexibility in terms of data transfer between the embedded system and the computer. The system that I’m developing when connected to the computer is executed in USB HID mode, where I can change a series of parameters inside of my system, after that, my system enter in USB CDC Serial mode with the objective to obtain more The operational system doesn’t allow updating the driver provided by the microcontroller manufacturer. Recently the Windows 10 had a series of troubles with USB drivers. I’m embedded systems developer and I need to use the USB interface, it’s essentials for my applications.
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