Search the Community

New Digital Discovery user. I did not purchase this device for its excellent documentation or thorough applications examples (which are not so great), but because it can capture SPI at 800MHz with the special adapter. I understand that the Digital Discovery will stream the captured data to memory and I can save it to disk. I'm debugging a difficult SPI issue, and need to see as much detail as possible (hence the 800MHz). Out test code captures some 30,000 rows of 14 consecutive 14-bit reads at an SPI clock speed of 27.5 MHz. This is a whole lot of data. We need to see the protocol capture results and compare it with what our embedded system is reporting. We read a very slow, clean R/C ramp (falling), gather all the data, and create a statistical plot which tells us how many "hits" we get on a certain bin value. Here's a snip: In this example, and despite the fact that our input ramp is changing in a very linear fashion (and therefore we should see equal distribution), decimal 4083 (ending in 100011) has far fewer hits than those adjacent. Each column (in the green) is a single SPI read of our ADC. We do 14 through DMA (very fast), and then repeat without much delay. I thought Digital Discovery would (a) trigger on the falling chip select, and (b) keep recording the data stream (ignoring subsequent chip select cycles). It doesn't. Instead, it captures the first 14 samples and no more data after that. Hopefully it's possible to trigger on CS (going low) and just keep sampling until I press stop. (Ideally if there's a timeout value allowing us to stop once CS stays high for a certain duration, that would be ideal). Finally, I have no idea how to save my data to a file and in a certain format. My setup: Please help this new user. I suspect it's simple, but the online docs are not very revealing, and experimentation isn't getting me far. Thanks!

I have a Digilent Nexys 4 board with me, and a medical device that provides streaming data via USB slave out, and I understand that my board has a USB HID, but it is connected to a PIC uC which converts it to PS/2 signal for me to use it. I was trying to implement a PS/2 controller to read this but then I came across this post on your forums where a Digilent technician said that video cameras are not supported, only mice and keyboards are. So I'd like to know how to connect a non mouse, non keyboard USB device to my board. This isn't an easy thing to Google so apologies if the answer was in the open. Regards