Binary, BCD, Counter ???

[Phld]

Hi,

I'm currently working on a project where I'm running out of pins on a
PIC. This is one of the bigger PICS so I am unable to expand on the
processor. Basically I need to be able to signal 8 outputs from a
single pin on the PIC. This is what I need in a nutshell:

Pulse on a single pin from the PIC to set a number of outputs (upto 8+)
Once set pulse another pin to enable the selected outputs.
Have the ability to reset the chip.
Be able to set all 8 (or more) outputs indipendantely.

Does anyone know of such a chip?

Please excuse my lack of electronics speak. I'm new to electronics!

TIA

Phil.

 

[Spehro Pefhany]

Hi,

I'm currently working on a project where I'm running out of pins on a
PIC. This is one of the bigger PICS so I am unable to expand on the
processor.

So, you've used up all 68~70 I/O pins on an 18F8x20 or dsPIC30F?

Basically I need to be able to signal 8 outputs from a
single pin on the PIC. This is what I need in a nutshell:

Pulse on a single pin from the PIC to set a number of outputs (upto 8+)
Once set pulse another pin to enable the selected outputs.
Have the ability to reset the chip.
Be able to set all 8 (or more) outputs indipendantely.

Does anyone know of such a chip?

Not precisely, not offhand. Normally I'd use several pins to control
an inexpensive HCMOS buffered shift register. In rare cases maybe even
another micro (which could use a single pin if you came up with an
appropriate protocol). If I didn't care about price or availability I
might consider a DS2408, but that would be a chilly day in Hades.

Please excuse my lack of electronics speak. I'm new to electronics!

TIA

Phil.

Best regards,
Spehro Pefhany

 

[Jan Homuth]

Google for '8255' ...

Get the data sheet, read it.
Have a look at: http://www.boondog.com/\tutorials\8255\8255.htm

grtnx
/jan