OT: Lighting Effect Needed: is there a chip that...

[nirvanas silence]

I want to mod my car taillights to light up in series.  Basically, I want a chip that works so if the bulbs are set up 1-2-3-4, I want:
1 to light up first and remain lit the whole the cycle.  Then 2 to light and remain lit.  Then 3, then 4 flashes and the whole cycle restarts.  This is often done on cars with 3 taillight bulbs, but mine has 4 so its alot more difficult.  I designed something using a 555 timer per bulb, but thats 8 total (left and right) and a ton of troubleshooting.  I need to figuere the discharge time and adjust the rate just right.  If there is something that does it in one chip that would be perfect.  Any ideas?  Thanks.

[mikeb]

an OT addition to the title would be nice .....

Anyway, use a PIC,even the simplest ones have 4 output lines.

Mike

[niftydog]

why you would want to do this I'll never understand... but I guess that's just me showing my age! (I'm only 27! Sheesh!)

anywho...

This sounds like a job for a PICAXE. This example code is incredibly simple, and hooked up to appropriate relay circuits would do what you want.  You could even get fancy and have multiple sequences, with varying delays (as short as 1mS).

Code Select Expand

main:
symbol ONE = 6 'name the output pins
symbol TWO = 7
symbol THREE = 8
symbol FOUR = 9
if pin0 = 1 then light 'if pin0 high, start light sequence
light:
high ONE     'light one on
wait 1          'wait 1 second
high TWO      'light two on
wait 1            'wait 1 second
high THREE     'etc
wait 1
high FOUR
wait 1
low ONE 'light one off
low TWO 'etc
low THREE
low FOUR
goto main 'if pin0 still high, sequence continues

failing that, logic chips. Maybe a shift register, or a counter... even a quad flip flop chip hooked up together (ie; counter) But for flexibility you really want a PICAXE.

[nirvanas silence]

THanks Niftydog, you've been helping me alot today.  I really need to read through my books, its been forever since I've been through this stuff.  Right now I'm even lookin at 555 timers and relays so I could get away with just 4 small circuits (using DPDT relays).

I cant find any simpler PICAXE schematics, got any good resources?

[niftydog]

the trouble with four separate 555s is that they won't ever be in sync. They'll drift all over the shop and your sequence will essentially be psuedo-random.

If you've worked out the circuit to drive realys from a 555, just pick it up and plonk it on a PICAXE chip. Something like this would suffice (replace the motor with the coil of the relay);



The circuit for programming the PICAXE08 is simple, make up a simple serial cable, download the free software, make this circuit and go for it! Note that the program example I gave was not for the 08 chip, but it can be easily modified to suit. The programming resistors don't need to be there on the "application" circuit, hence freeing up 'out 0' for use.



The PICAXE website is a fantastic resource, perhaps search the forums for others doing similar things to their cars.

The software, whilst a large download, comes with a whole bunch of documentation to make the job easy.

[Torchy]

PIC is way ott. You need a 555 set up as a clock feeding either a 4017 decade counter or a LM3914.

This is what you want http://www3.telus.net/chemelec/Projects/Knight/Knight-Rider-Lights.jpg
but remember to use trannies for the bulb loads instead of LEDS. If you want more circuits like this try

http://www.uoguelph.ca/~antoon/circ/circuits.htm
http://www.4qdtec.com/
http://ourworld.compuserve.com/homepages/Bill_Bowden/homepage.htm
:lol:

[nirvanas silence]

Torchy, thanks!!!  That circuit is perfect.  This is actually going on my 1989 firebird, same body style as KITT.  Where in NE are you?

Thanks for the PICAXE reccomendations as well, I'm gonna read up on that for future reference.

[Torchy]

Between Sunderland  and Newcastle

[mikeb]

PIC is way ott. You need a 555 set up as a clock feeding either a 4017 decade counter or a LM3914.

I built a phaser around a LM3914, and being a software guy *I* still think a PIC would be easiest ... but that's just me!  

Mike

[Torchy]

MikeB ... Seemed to me like a pic would be too complicated (read expensive) for what is essentially a simple circuit that can be built with off-the-shelf components. A PIC starter kit here in the UK is like £100+.

Didn't mean to offend anyone  :oops:

[R.G.]

The 3914 does the job, just feed it a voltage ramp.

A CD4015 shift register ($0.30), a dual AND gate package ($0.20) and a 555 does it too. Tie the input data line high, take the light bulb drivers off the successive Q0,1,2,3 outputs, and use AND gates on all the output bits plus the clock to the reset line. The 555 makes the clock for the unit.

If the unit is at all 0's, then at each clock you clock in a 1. The outputs fill up with 1's in order, and when the fifth clock happens, the ones in all the outputs and the clock pulse the reset line and reset the chip to all 0's.

This is one of the few applications that are cheaper with hard logic than a PIC like the F629. It's almost a wash.

[Torchy]

Try this with a 4017 & 555 ....

//www.uoguelph.ca/~antoon/gadgets/kit.pdf

[mikeb]

MikeB ... Seemed to me like a pic would be too complicated (read expensive) for what is essentially a simple circuit that can be built with off-the-shelf components. A PIC starter kit here in the UK is like £100+.

Didn't mean to offend anyone  :oops:

100 pounds+? Crikey!

No offence taken or intended - the point was depending on your background some approaches might seem easier than others. And also, may well depend on what parts you have to hand (surveys floor of workroom covered with PICs of all descriptions and empty 555 component drawer) ...

Mike

[toneman]

can U say "sequencer"

good

now google it...

peace

[smoguzbenjamin]

a 4011 with 555 timer should also be able to dit it. Use it to drive relays and you can do Night Rider with your car

[lovekraft0]

This one doesn't even use a 555:
One 4011 and one 4017
And this one uses a ULN2001N Darlington array to drive 12 volt bulbs:
Knight Rider Lights Project

[niftydog]

A PIC starter kit here in the UK is like £100+.

Christ on a bike!

PICAXE!! Try more like 10 pounds for a starter kit. But, you don't even need it.

£1.50 for a chip, two resistors and a three wire serial cable is all you need to program it.  Software is a free download.

(incidentally, it's not that much different for a PIC in-circuit programmer)

One IC, fully customisable solution.  Just add a darlington array driving relays (or whatever) and you're done.

I even wrote some code to get the OP started! And you're not limited to a "knight rider" scanning display, you can virtually do anything you want, including having multiple sequences.

Hell, all of these suggestions are great! Just felt I had to set the record straight about that £100 thingo!

[nirvanas silence]

Ok, I need to use the LM3914 due to the fact that it allows the bar lighting feature and not just pulses like the 4017.  New question, can I use the ULN2001 to drive 2 bulbs?  I want to wire the left and right side bulb with the same driver/relay so I don't get any synching problems.  Or maybe use the LM3914 to drive two ULN2001 drivers?  ACtually the ULN2801 has 8 NPN darlington pairs as opposed to the ULN2001 only having 7.  So the 2801 I can use just 1 chip to drive both the left and right side.  If the LM3914 can drive a pair of darlington relays, I am really in luck.