Please. Stop digging a bigger hole for your self. There is a reason you have not had a single positive comment about the example you posted.
Please. Stop digging a bigger hole for your self. There is a reason you have not had a single positive comment about the example you posted.
Absolutely right. What Bruno has done is to combine the scheduler and despatcher into a single ISR. It would make better use of resources and make the system more responsive if only the scheduler were in the ISR.
Ian
This is something I would like to build. It will not be a timer, it will count objects passing a point.
I have several chips on order: 7447, 7448, 74192, etc... I'm looking for something I can work up on a bread board and then possibly put on a small project PC board from Radio Shack.
It will eventually go into a paintball marker that has been built to look like the Pulse Rifle from Aliens.
First off, join the 21st Century and use 'HC parts ;-)
...Jim Thompson
-- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | It's what you learn, after you know it all, that counts.
At the suggested speeds, the CD4000 series would be a better option. You don't need to worry as much about the voltage regulation.
-- -- kensmith@rahul.net forging knowledge
Thanks, but I need a display. Preferably 3 digits using 7-segment LEDs.
I have a schematic from an OLD Radio Shack book that uses a 555 to drive a 7490 that dumps into either a 7447 or 7448 and then into a
7-segment LED. I'd like to get THIS to count down and it would be great if I could get it to use DIP switches to preset a number using binary.I'm going to use an IR LED emitter and receiver to count objects passing a point (piantballs leaving the barrel or hopper).
In article , Bob Monsen wrote: [....]
I assume that on a PIC, you can't push a value onto the stack so as to force the non-interrupt level to call the desired routine. If this is true then using the busy loop idea is a good one. Without it, your timed routines will be harder to code.
-- -- kensmith@rahul.net forging knowledge
don't need to worry as much about the voltage regulation.
What ever it takes... I just need a schematic.
Really, I'm not looking to count more than 15 objects per second...
Check out the 74HC192. It may be the right part for you.
-- -- kensmith@rahul.net forging knowledge
Do you want the up-down feature too at this time?
It makes a difference in what I'd suggest.
-- -- kensmith@rahul.net forging knowledge
Counting down is more inportant than presetting the max count.
I don't know about the larger PICs, but for the 12 and 16 series, the call stack is in hardware, and is not accessible to the programmer (it is also limited to 8 calls, and wraps. Sigh...).
-- Regards, Bob Monsen If my theory of relativity proves to be correct, Germany will claim me a German, and France will claim me a citizen of the world. However, if it proves wrong, France will say I¡Çm a German, and Germany will say that I¡Çm a jew. Albert Einstein (1879 - 1955)
The 18 chips, have larger stacks. Typically perhaps 20 deep (still not large to handle anything other than call/return operations). You can also access the 'top of stack' value, and the stack pointer. This allows you to write a software stack, to extend the existing stack if required. However it takes several instructions to access a single value (typically three read or write operations on the larger chips - the stack is 21 bits wide on these), then the I/O to the pointer.
Best Wishes
"Ken Smith" a écrit dans le message de news: dums6n$3fl$ snipped-for-privacy@blue.rahul.net...
Yes, push and pop instructions do not exist on pic MCUs, they have to be made by software. Otherwise, cheating with stack return values is a good assembler trick, but it would be risky to use it with a high-level language as C because low-level registers are controlled by compiler.
Bruno
Some of the 8051 C compilers have special "not really C" stuff added to them to make such stuff safe to do. They usually appear as some sort of magic variable.
-- -- kensmith@rahul.net forging knowledge
thatr method has disadvantages too, what if the routine that's being called should be uninterruptable?
Bye. Jasen
RoutineName: CLR EA ... etc ...
-- -- kensmith@rahul.net forging knowledge
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