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ReddyK

Fri Aug 18 2006, 03:07PM

Registered Member #92 Joined: Thu Feb 09 2006, 03:11PM
Location: Indian Trail, NC
Posts: 39

Hello,
I do not know the first thing about PICs however, it seems that a PIC would be the best solution to my problem. I want to turn on 10 leds in succession and then reset and do it again. I tend to be 'a search the internet until I find it and then copy it kind of guy'. I have searched but not found any PIC programs that do what I want. If someone would be willing to write the code for me I would gladly pay them for thier time.

I have a universal programmer that I bought to burn chips for my car and it does PICs. I would love to learn C language or somthing like it but it just does not seem to make sense to me yet. I found a C language class to download but it only works on XP which I don't have. I have gone through two tutorials on programming they just didn't have much on the code and what it means. They quickly went to how to burn a chip or talk about problems with the programmers.

Any help would be appreciated.
Thanks,
Steve

Wolfram

Fri Aug 18 2006, 04:14PM

Registered Member #33 Joined: Sat Feb 04 2006, 01:31PM
Location: Norway
Posts: 971

A simple running light? A CMOS 4017 would propably be the simplest solution to that. However, making it with a microcontroller would give a lot more flexibility (different patterns etc.). I'd suggest learing assembly language, as PIC assembly is quite easy to learn (only 35 instructions, and many of them are in the same group, so if you know one of them you know all of them).

ReddyK

Fri Aug 18 2006, 07:07PM

Registered Member #92 Joined: Thu Feb 09 2006, 03:11PM
Location: Indian Trail, NC
Posts: 39

A running light is all I can seem to find however, I need the lights to come on in succession and stay on until all are lit and then reset. I find alot of sequence light variations but, none keep the light on they just flash them.
Thanks,
Steve

Jrz126

Fri Aug 18 2006, 08:20PM

Registered Member #242 Joined: Thu Feb 23 2006, 11:37PM
Location: Erie PA
Posts: 210

do you need 10? or you be able to get away with 8?

You could do this pretty easy with a single 8 bit shift register.
The shift input would be connected to +5V, and the reset pin would be connected to the last output. then drive the clock signal (from a 555 or whatever). On each clock pulse, another '1' would be shifted in, turning on the next LED. When a '1' is shifted into the last bit, it will trigger the circuit to reset and start again.

Though you really arent limited to 8, you could cascade as many shift registers as you wanted.

ReddyK

Fri Aug 18 2006, 10:30PM

Registered Member #92 Joined: Thu Feb 09 2006, 03:11PM
Location: Indian Trail, NC
Posts: 39

Yea I really need at least 10 leds and 12 would probibly look better. They are for turn signals on my bike. I made led turn signals and a 120 surface mount led tail light. I didn't think the turn signals were flashy enough and decided to make them sequence somehow. So here I am looking for help to accomplish this.
Thanks,
Steve

Bjørn

Fri Aug 18 2006, 11:32PM

Registered Member #27 Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058

The line should read "include <p16f84.inc>", the forum software is buggy. I have not tested it, I just wrote it down.

list    p=16f84
	include <p16f84.inc>
	__config _XT_OSC & _WDT_OFF & _PWRTE_ON & _CP_OFF

	CBLOCK	.12
	  t1
	  t2
	ENDC



main	movlw	.0
	banksel	TRISA
	movwf	TRISA
	banksel	TRISB
	movwf	TRISB
	banksel 0

loop	clrf	PORTA
	clrf	PORTB

	bsf	PORTA,0
	call	pause
	bsf	PORTA,1
	call	pause
	bsf	PORTA,2
	call	pause
	bsf	PORTA,3
	call	pause

	bsf	PORTB,0
	call	pause
	bsf	PORTB,1
	call	pause
	bsf	PORTB,2
	call	pause
	bsf	PORTB,3
	call	pause
	bsf	PORTB,4
	call	pausw
	bsf	PORTB,5
	call	pause
	bsf	PORTB,6
	call	pause
	bsf	PORTA,7
	call	pause

	goto	loop


pause	clrf	t1
pl1	clrf	t2
pl2	decfsz	t2
	goto	pl2
	decfsz	t1
	goto	pl1
	return

	end

McFluffin

Sat Aug 19 2006, 07:22AM

Registered Member #119 Joined: Fri Feb 10 2006, 06:26AM
Location: USA
Posts: 114

I'd go for the micro just because I'm a C programmer and its good experience, but, that aside, there is a fairly easy way to do 10 as Jrz126 said. Use a 4017 decade counter chip and drive it with a 555. That will give you 10 outputs and is easy to set up.

phil

Sun Aug 27 2006, 06:28AM

Registered Member #314 Joined: Mon Mar 13 2006, 03:12AM
Location:
Posts: 52

This is the chip i normally use, supports 33 I/O 's so you have a little room to expand if you'd like

. just go here

. and if you only need one chip you can create an account and "sample" up to 4 chips a month. just go under the "samples" section of the web and look up the chip in the link i posted. It also has an ICSP, also known as an "in circuit serial programmer", so you don't need an expensive PIC programmer to program it. The serial port hookup is in the datasheet which can also be found on the site.

tecNik

Wed Aug 30 2006, 10:21AM

Registered Member #77 Joined: Thu Feb 09 2006, 10:24AM
Location: Leicestershire, England
Posts: 26

The LM3916 bargraph display driver supports 10 outputs, can drive LED's directly and can be sampled from National. You just need to provide a rising analog input for what you want. Easy with simple cap charge/discharge circuit (or 555).

ReddyK

Wed Aug 30 2006, 04:05PM

Registered Member #92 Joined: Thu Feb 09 2006, 03:11PM
Location: Indian Trail, NC
Posts: 39

Thanks for the advice. I have power 8-bit shift registers and an assortment if pics on order. My led's are 80ma so I have to be careful what I am driving them through. I'll let you know how it's going when I get the parts.
Thanks,
Steve

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