Hi guys, I'm building an electrical device which will be controlled by computer. It will have an embedded microcontroller and will use USB to communicate with the PC. I believe this calls automatically for a device driver, correct? And for using the machine from the PC, interacting with it, that calls for a userspace program, correct? I mean, doing things differently, such as all in userspace or all in-kernel, would be bad form, right? My question is in case the machine is used in an industrial context where there is really only one usage and one kind of interaction that follows a pre-determined procedure (therefore totally automated). This could give extremely high priority of execution, I guess. Similar to a factory robot controlled by a computer. Would it make more sense to have everything in kernel space, while the userspace (if any) would only serve the purpose of reporting? To be a lot more general, I find it simple at first glance to understand what goes where between kernel and user space. But despite this, I often find myself in a gray zone (to my perspective) or I find myself trying to "fit" something I feel is the wrong place. I would need to read more on the philosophy of these different processing spaces, about the design behind them and the usage this philosophy prescribes. Anyone know where I could read about this in greater detail? Thanks, Simon