impulseballer

ok i want to build a chase like knight rider. i've seen the diagrams etc. for say a 20 led one etc. i want to do a larger one maybe around 40 leds or so long stacked by 2. can anyone tell me or maybe make a diagram and a printable circuit layout that i could make a PCB with. thanks in advance.

Gayan Soyza

For a bidirectional running system it needs more components & a large circuit.

A simple johnson counters like 4017 can drive 10 outputs but its shifting one side unless you add some diodes to the output to move them both sides.

If you need more outputs you need to cascade them.

Just search "cascading 4017" or similar.

__________________
Gayan
Forum Supporter

davidbball13

if i wanted to do the knight rider with 10 LEDs how would i add the diodes could i use a 4148 switching diode if so how would i do it. or if i had to how would i use it with 6LEDs

3v0

In the first issue of JPUG I wrote an article on how to sequence the 6 LEDs on the Junebug. If you set the speed and number of LEDs illuminated at once it is the same effect. Even if you do not use a junebug it will show you how to sequence LEDs using a PIC.

The Junebug LEDs are Charlieplexed. But you can get the same result with similar (less complex) code for for LEDs hooked directly to IO pins.

If you are new to uC's check out the tutorials in my signature.

__________________
To control the world from your PC with USB I suggest USB Bit Wacker

3v0's Tutorials for ABSOLUTE BEGINNER
C, PIC 18F, MPLAB® and MCC18 Compiler

blueroomelectronics

Using Charlieplexing 5 I/O pins can control 20LEDs

__________________
Bill
Smart Kits build Smart People
http://www.blueroomelectronics.com

synthius

I was able to do this with an atmel microcontroller. Along with several other sequences.

http://youtube.com/watch?v=0MSzyGse7g0

Ubergeek63

Why?

A 74HC193 bidirectional counter, a 74HC4067 demux, and a F/F for feedback from the demux to the direction pins will work fine.

While it is easy to extend to 40 LEDs, it would make more sense to increase the direction logic, and multiplex them. Of course he did not say if you wanted more than one on at a time either.

impulseballer

yeah guys keep in mind i hardly no squat about electronics etc. i look at this site http://www.bit-tech.net/modding/2002...knight_rider/3 which shows how to make 10 LED ones etc. The only thing I can do is actually make the PCB with the diagram and PCB graphic provided on that link. I can soldier all the pieces etc. Anyone could possibly make me a PCB printout and diagram like the one on the site for 2 rows or 40 leds?

like this:

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

gramo

Sounds like you need a breadboard


Google image "electronic breadboard" to get an idea of what I'm talking about.


Then grab a Protoboard PCB - its a generic PCB with etched traces and drilled holes with similar use as a breadboard, but more permanent

__________________
Spency.

How many PC programs are developed with assembler? Then why use it with PIC's?

PIC's and interfacing with other devices - a PIC Basic Guide @ digital-diy.net

impulseballer

i know wut a bread board is. what i really need is some electronics genius to supply me with a parts list, and a component and track layout. i can build it but i don't know how to engineer it or what specific things i need to put it together.