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74ls166 — Parallax Forums

74ls166

ArchiverArchiver Posts: 46,084
edited 2002-10-12 17:12 in General Discussion
Unfortunately I've not been able to find any of the parallel to
serial chips (in stock) mentioned in any of the appnotes or websites
I've checked. I do have a few PCF8574As on order (two weeks away).

In the meantime I found a chip, the 74LS166 that does parallel to
serial but my (fumbling) attempts at using it are going nowhere. I
can't seem to find an example of the chip in use on any sites.
Anyone have a link to one?

Here's a PDF link http://www.fairchildsemi.com/ds/DM/DM74LS166.pdf

I thought to try it like an SPI chip, using shiftin to read it. Not
sure if this is even appropriate.

Here's what I thought was the most likely setup.

Pin 1 (Serial in) to P10 on the stamp as Data_in
Pin 7 (Clock) to P9 on the stamp as Clock
Pin 15 (shift load) to P8 on the stamp as latch

P2-5 -> switches -> 10k resistors -> +5v
P6 (Clock inhibit) ground
P8 (ground) ground
P9 (clear) ground
P10-12 (inputs) ground
P13 (output) open
P14 (input) ground
P16 +5v

Hard to figure out these chips. Datasheets for similar chips from
the same manufacturer all use different terms for the same pin
functions etc...
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