Question.... Two programs running in the same time - Electronic Circuits Projects Diagrams Free

kikefasa · 11th October 2007, 07:59 PM

Hi,
I need to know, if is posible in the pic16f84a, to start a program, keep this program running, an start another, and Who?

Regards.

ronsimpson · 11th October 2007, 08:29 PM

YES-----Almost!
A 16F84 and most computers can only do one program at a time. Your PC may look like it is working on many programs but it is only working on one at a time.

I have a PIC16Fxxx running a program most of the time. Every 0.01 seconds the computer jumps to an interrupt program. It runs for about 0.001 seconds then goes back to the main program. To the human eye it appears that both programs are running at the same time.

**Nigel Goodwin** · 11th October 2007, 09:22 PM

Quote:

Originally Posted by kikefasa

Hi,
I need to know, if is posible in the pic16f84a, to start a program, keep this program running, an start another, and Who?

The main question is why?.

Generally you can do what you want in this sort of thing, but it's far better to be specific - you could write a real time multitasking OS, but you absolutely cripple performance, as Windows does!.

I suggest you ask us exactly what you're trying to do!.

kikefasa · 11th October 2007, 09:43 PM

I use RA0, RA1, RA2 and RA3, to control a step by step motor. RA0 goes to the first coil, Ra1 goes to the second coil and etc.

I need that RA0, RA1, RA2 and RA3 run always, because the others pins, RB0-RB7 as been used to sensors and switches.

How I do to keep RA0, RA1, RA2 and RA3 working ?

**Nigel Goodwin** · 11th October 2007, 09:51 PM

Dead simple, and standard programming - you use a timer interrupt to move the stepper.

It's basically how Windows (or Linux) does multi-tasking, but without the overhead.

kikefasa · 11th October 2007, 09:58 PM

Who I do that?

**Nigel Goodwin** · 11th October 2007, 10:13 PM

Quote:

Originally Posted by kikefasa

Who I do that?

Learn to program?.

For a start I would suggest dumping the antique 84?, it doesn't have a lot going for it - it's replacement the 16F628 is cheaper and higher spec.

My tutorials show how to use tmr2 to multiplex seven segment displays, or 64 LED's - similar timer code code be used to drive a stepper motor.

ssylee · 12th October 2007, 12:26 AM

You can also get some sample chips from microchip for free. That goes for antique chips to the really fancy chips. For programming, on top of learning on some hardware characteristics from sample code and datasheets, may be helpful to look at structures of c programs as well or assembly.

**3v0** · 12th October 2007, 01:35 AM

Quote:

Originally Posted by Nigel Goodwin

- you could write a real time multitasking OS, but you absolutely cripple performance

I would not suggest using a RTOS on the 16F84 but they do have their place.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Title	Starter	Forum	Replies	Latest
Using Oscilloscopes	mechie	Electronic Theory	9	29th November 2007 10:49 PM
10 MHz only WWW time signal receiver	atferrari	Electronic Projects	3	6th July 2007 02:17 AM
Logic switching time on an input port question	FusionITR	Micro Controllers	8	24th March 2006 03:58 PM
Multisim Simulation Speed Question	otacustes	Electronic Projects Design/Ideas/Reviews	8	23rd March 2006 07:20 PM
PBX question	waqar	Electronic Projects Design/Ideas/Reviews	0	30th March 2003 07:21 PM

11th October 2007, 07:59 PM	(permalink)
kikefasa	Question.... Two programs running in the same time Hi, I need to know, if is posible in the pic16f84a, to start a program, keep this program running, an start another, and Who? Regards.

11th October 2007, 08:29 PM	(permalink)
ronsimpson	YES-----Almost! A 16F84 and most computers can only do one program at a time. Your PC may look like it is working on many programs but it is only working on one at a time. I have a PIC16Fxxx running a program most of the time. Every 0.01 seconds the computer jumps to an interrupt program. It runs for about 0.001 seconds then goes back to the main program. To the human eye it appears that both programs are running at the same time.

11th October 2007, 09:43 PM	(permalink)
kikefasa	I use RA0, RA1, RA2 and RA3, to control a step by step motor. RA0 goes to the first coil, Ra1 goes to the second coil and etc. I need that RA0, RA1, RA2 and RA3 run always, because the others pins, RB0-RB7 as been used to sensors and switches. How I do to keep RA0, RA1, RA2 and RA3 working ?

11th October 2007, 09:51 PM	(permalink)
Nigel Goodwin	Dead simple, and standard programming - you use a timer interrupt to move the stepper. It's basically how Windows (or Linux) does multi-tasking, but without the overhead. __________________ PIC programmer software, and PIC Tutorials at: http://www.winpicprog.co.uk

11th October 2007, 09:58 PM	(permalink)
kikefasa	Who I do that?

12th October 2007, 12:26 AM	(permalink)
ssylee	You can also get some sample chips from microchip for free. That goes for antique chips to the really fancy chips. For programming, on top of learning on some hardware characteristics from sample code and datasheets, may be helpful to look at structures of c programs as well or assembly.