@Rick_2047 I'm really thinking about a programmer that supports debugWire, but they cost a lot of money and I doubt if I can reproduce this problem well enough to catch it
But I am convinced that I understand what is happening, I just need to adjust a 'calibration' parameter :)
As I look at it from a 'calibration' point of view and probably being able calculate the calibration values automatically after compile, I can easily store them in EEPROM. Hence my EEPROM questions :)
It's just that when I change the code (or perhaps compiler) the required values may change :-/ Hence my thought of using assembler.
That example program uses the same mechanism I use. It mentiones fuzz = 8, I came up with a pretty similar mechanism, I just have to figure out what exact number I need.
@Rick_2047 Do you know how I would include assembler in the C-source?
@Rick_2047 I agree, but i know my ISR will only be called every 20000 clock cycles. That equals some 15000 instruction. So a single if/then should not be an issue.
@jippie, missed you but yep was just wondering about how the eeprom defaults from C went. Sounds like good advice from @Rick_2047 and @StaceyAnne above on your ZCD project, I'd expect to get in the order of 1uS accuracy so trying to calibrate will probably hide a logic problem that'll bite you later.
@StaceyAnne, can't help there, my most complex FPGA / VHDL code counted from 0-9999 on a 7-segment display and while it worked it consumed about 25K gates so I'm guessing it wasn't good code at that.
@PeterJ, It's amazing how far FPGAs have come, It's easy to get away now with coding completely in C for most applications using the uBlaze. All of the VHDL is pre-written by Xilinx. I'm a bit torn about it though, since I prefer VHDL over C.
@Kortuk I think i have a solution to Davids answer in this meta question. We could have a blog with articles ranging from simple how-tos, tutorials through to more complex things like choosing a FPGA for a project.
@StaceyAnne, I'm a bit the other way having more of a software background. I bought a Digilent board a few years back for general learning to have an extra skill, but every time so far I have a real project where I think an FPGA would be a great solution I seem to think of a way to use say an ARM and some simple extra logic / clever programming to do it.
That's just me though of course they have their place depending on what you're doing.
@PeterJ, I work mostly in the aerospace/defence/medical industries, where they're mostly used for pre-processing high speed data in preparation for CPU processing.
@StaceyAnne, sounds cool, they certainly are good for high-performance / relatively low volume applications, what I work on is normally too mundane to really need them, normally either not enough high speed requirements or something near enough off the shelf.
It is a good starting point, I'm inclined to prefer Xilinx FPGAs, and I like how they have a wrapper around the code, that really helps (initially) with the HDL
@Rick_2047, while a 8080 here's something I've been meaning to try on my 3E, space invaders fpgaarcade.com/spc_main.htm but it's probably a good indication a processor of roughly that complexity will fit with some other logic
@BMitch We have had the exact same question 3 or 4 times on EE.SE, it is not that niche. People want to do it, it just does not fit our site. Moding the battery for your computer seems like Super User but I have been wrong on that more then once.
@W5VO Awesome, I ordered something I could not find at my house for my project, so i am looking forward to spending that hour goofing with things also.
@W5VO I ran into him once at a hotdog stand. He dropped by on his Segway. And by "ran into", I mean I was eating my hotdog and he showed up and ordered a hotdog, and then he went on his way wherever he was going.
@Kortuk It was a deep connection, because it was at Top Dog. I went there because Top Dog was the local hot dog stand at Berkeley, and I was having a nostalgic hot dog. And the guy at the counter told me Woz drops by there every week or so for a nostalgic Berkeley-style hot dog as well.
Unfortunately San Jose Top Dog is closed now (or renamed to Supreme Dog so its not the same at all) and so Woz and I can only get our nostalgic hot dogs when we are actually in Berkeley.
@Kortuk you may want to edit the pinned message above to be a bit more explanatory about the event. (Also, you may want to unpin your other "I'm leaving the google hangout on Saturday"... message)
@Kortuk Nah, your choice. Just that I wasn't sure if you wanted both -- one had a link and one didn't. Wasn't sure if you knew that you could edit other people's chat messages :)
