On 12/05/2013 03:31 PM, Matthias Weber wrote: >> we are a group of students from University of applied sciences in Augsburg. >> We're currently working on a project where we implement software for running >> a hardware board developed by another student as his bachelor thesies a few >> years ago. >> >> The current hardware consists of a ATmega32U4 microcontroller, an Altera Max >> II CPLD, 1 MB SRAM and some driver ICs - it is a 24 bit logic analyzer.
I doubt the ATmega32U4 will do you much service in getting 24 bits of data through a low-speed USB connection to the host computer. If you think bandwidth, you have too ask if you have enough available to have any usable sampling frequency. Of course, if you trigger and sample than you can transfer the buffer, and bandwidth is of less concern. I think it's doable. >> Control and data communication between PC and uC will be handled via a >> virtual serial interface (via USB). In my opinion, you should avoid this like a plague. Implement a proper USB protocol, and don't emulate over serial. It will take more effort to write a serial protocol and emulate it over USB, than it will to just implement pure USB. I did an LPC programmer this summer, pure USB, and the protocol was not at all complicated >> The control/ data transmission protocol is not defined yet, but I have taken >> a closer look at the currently supported hardware. Look at the fx2lafw protocol. I think it provides a good starting point. >> For the first few steps we will try to control the analyzer in a simple >> terminal, so we might use ASCII characters, I think it's a waste of resources to write an ASCII protocol only to replace it later. Write the firmware and software at the same time. It's fairly easy to do this with libusb. Getting a handshake might take some tinkering, but I think the rest is a piece of cake. >> Can you please give us a small hint where to start implementation/ >> integration in sigrok? I've seen that there is a demo device. Is it a good >> way to start here or is there any further documentation on how to integrate >> new devices? >> 'demo' is a different beast. I would start with a device that most closely matches what you are trying to create. Of the top of my head, I can think about buspirate (serial) and fx2lafw (USB). Good luck! Alex ------------------------------------------------------------------------------ Sponsored by Intel(R) XDK Develop, test and display web and hybrid apps with a single code base. Download it for free now! http://pubads.g.doubleclick.net/gampad/clk?id=111408631&iu=/4140/ostg.clktrk _______________________________________________ sigrok-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/sigrok-devel
