Can anyone recommend an I2C parallel to serial chip?

Archiver

I want to try making a keyboard out of pushbuttons (matrix type).
But I can't seem to find an I2C chip to do this. Basically the
opposite of a shift register.

I have seen the PCF8574A but that requires an extra latch line to
toggle it over to inputs. I can use it no sweat if needed. Just
seeing how pin-economic I can be.

Archiver

The PCF8574 will be fine and requires no extra line (just the I2C clock and
data lines). When you do a device read, it will tell you what it "sees" on
its pins. To be accurate, it is a shift register and each read is internally
buffered. To get the current state of the pins, do two reads and use the
second.

-- Jon Williams
-- Parallax


In a message dated 10/10/02 10:41:29 AM Central Daylight Time,
ghidera2000@y... writes:


> I want to try making a keyboard out of pushbuttons (matrix type).
> But I can't seem to find an I2C chip to do this. Basically the
> opposite of a shift register.
>
> I have seen the PCF8574A but that requires an extra latch line to
> toggle it over to inputs. I can use it no sweat if needed. Just
>




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