FW: ECM Bench Problem

[Don.F.Broadus at ucm.com]

> -----Original Message-----
> From:	Roger Heflin [SMTP:rah at horizon.hit.net]
> Sent:	Thursday, December 09, 1999 9:32 PM
> To:	gmecm at efi332.eng.ohio-state.edu
> Subject:	Re: ECM Bench Problem
> 
>  Right on the money Roger ,  74LS164   8 bit shift registers work great in
> cascade .outputs through 150 ohm resistor to drive led's.
> Pin 8 is clock input  pin 14,2,7  ground  pin 1 is the data input ( tie
> high). Clear tie  low to shift , (high to clear)
> Outputs a,b,c,d,e,f,g,h,   pins 3,4,5,6,10,11,12,13,   the output of the
> first 74LS164  (pin 13)  goes to( pin 8) of the next 74LS164 .You can make
> the register string reset it self by tying all of the clear lines to the
> last register (pin 10)     (8 bits X 5 chips= 40 bits) Each time a clock
> pulse is received the FF will toggle and light the LED. after 32 clocks
> All LED's will be on then on #33 clock all will reset.      
> 
> On Thu, 9 Dec 1999, Bruce Plecan wrote:
> 
> > Anyone know of a very simple cheap electronic way to illuminate 36 leds
> in
> > sync.
> > 
> > I need to pick the signal off of the 1-3-6-12-18-24-30,
> > Like for a 2.8/3.1L, DIS,  crank sensor would generate.
> 
> Use  a pic?  That seems to be the answer for almost anything.
> 
> Using discrete logic you owuld want to use a
> parallel-in/parallel-out shift register.  You would need 4-8bt ones,
> and 1 4-bit one, or 9 4-bit ones.   Use th parallel in to load the
> initial state and the parallel out for the signal you want to out.
> The shift-in/shift-out is cascaded from the previous to the next one
> and each time the input clock triggers it willl shift if setup
> correctly.  That is if you can still get discrete logic.  You will
> also have to carefully setup hte LEDs to not sink too much current
> into the outputs.
> 
> 				Roger