Re: Need to generate sequence 001, 010, 100, 001, 010, 100, ...

On Tue, 29 Apr 2008 16:06:58 +0100, Eeyore
<rabbitsfriendsandrelations@xxxxxxxxxxx> wrote:



John Fields wrote:

Eeyore wrote:
John Fields wrote:
Eeyore wrote:
Rich Grise wrote:
Eeyore wrote:
"jalbers@xxxxxxx" wrote:

I am looking for the simplest collection of logic chips that would
produce the sequence 001, 010, 100, 001, 010, 100, ...

I know that a PIC could be programemd to do this.

Yes a PIC.

You're not allowed to say "use a pic" without providing a schematic
and full code listing.

OK, use an '8051' then. 63 cents indicative price for this one. I don't
do PIC code but I could ask my nephew to do that !.
http://www.nxp.com/pip/P89LPC901_902_903-05.html


My first thought was a 3-bit shift register.

Far too many parts !

---
Note that the OP was aware that a PIC could be used, but asked for
"the simplest collection of logic chips" which would do the job.

Oh, OK. A counter with auto-reset is the answer then.

---
More specifically, a 4017, which is one chip less than shown in my
earlier post.

You still need a clock source of course. The 89LPC901 can do the lot.

---
Not without a programmer it can't.

_And_ it's not what the OP asked for.

Here's a single-chip solution with no clock needed:

(View in Courier)



V+--+-------------+---------------+---------------+
| | | |
[100k] 1/4 553 [R] 1/4 553 [R] 1/4 553 [R]
| +-------+ | +-------+ | +-------+ |
| | T|--+ | T|--+ | T|--+
| | | | | | | | | |
| | | [C] | | [C] | | [C]
| |__ | | |__ | | |__ | |
+-O|TR OUT|--|-+-O|TR OUT|--|-+-O|TR OUT|--|-+
| +-------+ | | +-------+ | | +-------+ | |
| | | | | | |
+--[1N4148>]--|-|---[0.1µF]---|-|-------------|-+
| | | | | | |
[100nF] | | | | | |
| | | | | | |
| | | | | | |
GND>+-------------+-|-------------+-|-------------+ |
| | |
OUTA OUTB OUTC


JF
.

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