Hello, I bought Logic Pirate from Seeed Studio. It works, but one thing is unexpected to me - noise before trigger. When I ground input 0 and hit record on OLS 0.9.7.2, I can see noise before time zero:[attachment=5] After zoom-in, I can see regular square wave[attachment=4]
The same goes when using the internal test signal and setting trigger on channel one:[attachment=3] Triggering works as expected, but the waveform before trigger is just wrong.[attachment=2] I assume trying to run UART analysis or something would lead to a lot of garbage here. It seems like I'm running the newest firmware https://code.google.com/p/dangerous-pro ... %2F_output [attachment=0]
Honestly, I have no idea what's going on here. I'm long-time user of logic shrimp viewtopic.php?f=58&t=2396 and this is something I didn't expect. On logic shrimp, the same waveform looks like this:[attachment=1]
sqk: you will not find much fanboys over here. Here is a lot of engineers, doing engineering work and fanboy / blogger crowd is afraid of those things. Try to write such as comment on hackaday or so and you'll se more of excitement.
Yes, I read that page - but I ended on statement "Alternatively, such a system is one that can simulate a universal Turing machine.". For me it sounded a bit recursive :-) So, can we consider writing BF machine for particular CPU as "good enough" validation for Turing completeness? BF is good known, so it seems like good reference. And what about machine that can hold only limited amount of program (long time ago I designed 4-bit CPU with 16 words of program memory), but whose instruction set would allow writing BF machine, if there would be more memory available?
Which date is competition deadline? :-) I'm definitely interested.
I'm probably going to look like complete idiot, but could anybody bring more light on Turing completeness? I tried to google for it, but I'm unsure. I have some understanding what it means, but I'm not sure how to validate, whether chosen CPU is turing complete. For example, my Fourbit computer - http://jaromir.xf.cz/fourbit/fourbit.html How can I prove Turing completeness?
But I'm definitely interested in contest. It's more that one year since I designed my last CPU, that's a rather long time.
By the way - I would suggest to ban PLDs from contest.
Now I want to try to configure it with BP. I downloaded package from here http://code.google.com/p/the-bus-pirate ... p&can=2&q= uploaded code to BP, converted svf file from Altera Quartus to xsvf file using converter in BP package, ran bpxsvfplayer and... error. [attachment=1]
[quote author="Bertho"]The real kicker is that a 32bit ARM is cheaper than an 8bit PIC/AVR for the number of gpios and functions I need.[/quote] Just curious, what was the GPIO count and features list you needed? I'm not going to persuade you to use another MCU, only doing my own personal research, this is another case study ;-)
Seems like you are going to have different usage patterns compared to me - I use only Microchip XC8/16/32 compilers and no external editors - so your mileage may vary.
Well, when it comes to speed, MPLABX works much better in Linux. I use it at home el-cheapo computer (250EUR in parts) and I'm absolutely happy with it. Much more powerful and expensive work computer got its power killed with Windows7 and MPLABX is not so comfortable here, but it is still "workable".
Regarding the functionality, no problems at all. Editor is much better compared to MPLAB8, navigation in projects too.
Bertho - you are right about tme PSP in those small PIC devices. I forgot about RS and RW. Those in bigger packages do have 16-bit PMP, but this is probably out of question for now. So, extra latch will be needed, probably.
Regarding the latch - some PIC18F, like PIC18F4620 do have PSP - paralell slave port, which seems to be suited for this task. MCUs like 18F46J11 do have paralell master port (PMP), which can be configured to PSP-like fashion.
But after all, I would use some 16-bit PIC (PIC24 or even dsPIC33). Those are really simple to program in assembly language (very nice instruction set, IMHO better than 8-bitters I worked with), quite powerful, but yet easy to calculate timing (no prefetch cache and stuff to make it complicated). And there is paralell master/slave port too. Just for inspiration http://benryves.com/journal/3672273
