Bart said:
Hi all,
I want to make 4 LED's light up in the following sequence (looping):
O O _ _
_ O O _
_ _ O O
O _ _ O
O O _ _
_ O O _
_ _ O O
O _ _ O
<SNIP>
And WHEW what a journey I've had! Many thanks to all, including John
Fields, petrus bitbiter, and Terry Pinnell for their schematics. After
setting up my 555 for something close to 1 herz so I can visually verify the
sequencing, I began on the discrete portion of the logic firing (did I say
that right?). Thanks to petrus bitbiter's link to the AAcircuit software I
could read the text schematics supplied by he and John Fields (later I
learned about fixed font in Outlook Express, doh!). In acquiring AAcircuit I
also stumbled across CircuitMaker Student Version which resembled Terry
Pinnell's posted GIF schematic. I breadboarded Terry's configuration first,
unsuccessfully. After researching the 4017 chip I found I also had to hookup
Vdd and ground on the chip (pins 16 and 8) and it CAME TO LIFE! Feeling full
of myself, I breadboarded petrus bitbiter's schematic, unsuccessfully.
Taking what I learned in my first attempt and researching other unrelated
schematics using the 4013 chip I found it is popular to tie pins 4,6,8,12
(set/reset) to ground and it COMES TO LIFE! Now I'm a genius, a player, my
crotch is huge. I breadboard John's schematic unsuccessfully but I'm not
worried, I'm bulletproof, I'm the digital James Bond. After trying different
combos of Hi/Lo on S and S-not/R and R-not and pulling the led's from
different branches/pins, I was able to have eight leds, four running the
sequence forward and the other four running the sequence in reverse. Ah, my
first digital orgasm!
I'm going to hardsolder John's circuit and use it to drive opto isolators.
It will be a handheld encoder simulator to troubleshoot digital readouts and
CNC controls on machinetools (John recognized petrus' circuit, labelling it
a quadrature encoder which assured me I had come to the right place for
help).
Can any of you guys relate to my excitement at completing my very first
logic/gate/digital/flip-flop/nipple hardening/led experience? I have many
analog stories to tell but think this experience will lead me to many more
adventures in gating/counters/timers/binary/hex/etc.
THANKS SEB !!
Bart