knight rider light project

[gizmo13]

Hello again,

It's been a while since I have been able to post (let alone look at), this
board. I am glad to be back because I need some electronics geniuses to
help me.
I am building a basic chaser light "knight rider" lighting project. I already have
the controller and I am in the process of building the light bar itself.
Here is what I need: The basic outline of the project is that BEFORE the
system starts to go through it's back and forth sequence, I want all eight
lights to come on for about 2 to 3 seconds and then start sequencing
back and forth like normal.
In another forum a guy said he has done so " I used the 74LS138 decoder multiplexer chip. With that circuit I simply used a 555 timer setting the RC network to hold a relay for about 1/2 of a second. I simply pumped all the prestage transistors with a positive signal at the same time with the relay and used small signal diodes to prevent backflow during regular scan...".
I tried to get the guy to tell me how to do this but I got no answer so here
I am.
Would it be possible for someone to draw me a schematic of what he is
talking about (or if you have a simpler way of doing it, keep in mind I don't
have access to a pic programmer so I have to do things the old fashioned
way).
If you need specs, I am running led's for the lights (don't like halogen bulbs
they draw too much current), the ic's for the controller are:
cd4060be, cd4070be and cd4028be.
This WILL be installed in a car so it will be run off 12v.
I know enough to tinker around with a few things but I have no clue
on how to get this "all on " effect.
I do plan to save a little cash and start studying electronics so I don't have
to bug you guys for help (BELIEVE ME I APPRECIATE IT)!!!!!
Thanks for any help/suggestions (if any) and I look forward to being more
active on the boards.

Craig

 

[Hero999]

Why not use a microcontroller?

It's probably the moswt sensible option as it will save a lot of money, soldering and space.

 

[gizmo13]

Again, I am a modest hobbyist at best. I don't really understand when you
say use a microcontroller.
Could you elaborate???????????//
And this gives me alot more incentive to take this "hobby" more seriously.
I am currently looking at online courses.



Craig

 

[Nigel Goodwin]

Again, I am a modest hobbyist at best. I don't really understand when you
say use a microcontroller.

Check my PIC tutorials, the first ones include an 8 LED 'Knight Rider' type effect - it's really VERY simple to do with a PIC, and you can easily program it to do EXACTLY what you want. It also use very few components - just the PIC (an 18 pin chip), 8 x LED's, 8 x resistors, plus a 5V power supply (my tutorial board includes a suitable 7805 PSU).

 

[picasm]

Whilst it is possible to make it using just logic chips, you may find that it won't look so authentic using leds.
This is because the original had a nice fading effect due to using lamps.

The fading effect can be simulated with leds but it makes the project a lot more complicated for you as you will need to learn to write microcontroller programs.

I suggest that you consider using a pic microcontroller and then build or buy a simple programmer (they are not very expensive).

You can start by reading the beginners guide and Nigel's pic tutorials at the top of the microcontroller forum:
https://www.electro-tech-online.com/threads/pic-newcomers-please-read-upd-0xd1.15035/

 

[gizmo13]

I already have a nice trail effect using caps so that's not an issue.
I was hoping to not have to spend any significant money on buying any kind
of programming device yet.
I wanted to throw this circuit together for a quick project to show some
people.



Craig

 

[kchriste]

Show us your circuit diagram since you already have a working circuit. It should be pretty easy to modify as the "other guy in another forum" has mentioned. How it's modified depends on how you are driving the LEDs. (I'm going camping for a week so I probably won't reply, but someone else may, once you provide a diagram of what you already have)

 

[gizmo13]

I'll draw up the diagram and post it in the next couple of days.
I know it would be easier to use microcontrollers to get my "all on effect"
but I am on a very tight budget and there is a time restraint (trying to get
this built for the 29th of september.
And remember the fading isn't the issue with my limited know-how of
electronics, I have already achieved a nice trail. Just need to get the
all on effect.

Thanks all.


Craig

 

[Nigel Goodwin]

I already have a nice trail effect using caps so that's not an issue.
I was hoping to not have to spend any significant money on buying any kind
of programming device yet.
I wanted to throw this circuit together for a quick project to show some
people.

Check https://www.electro-tech-online.com/custompdfs/2007/09/micro_pricelist.pdf, a PICAXE 18 costs £2.50, and no programmer required, everything else needed is a free download.

It's all you need for your project, it has 8 outputs you can use.

 

[gizmo13]

Thanks I will check it out.


Craig

 

[gizmo13]

ok.

I have finally gotten a chance to gets some pics of the two projects
I am trying to incorporate this effect on. I hope these come up correctly.



I hope this helps.


Thanks.
Craig