MCU I/O EXTENDER ?!? WHAT IS BEST CIRCUIT?

[mrcube_ns]

MCU I/O EXTENDER ?!?

Hi all,

I need to extend digital I/O pins on mcu.

Looong time ago (late 199x) I use Intel's 8255 to extend number of inputs for some pic mcu (think it was 16f84, can't remember now).


What is best circuit or IC to do it, today?

(I never used GAL, PAL, ALTERA or similar circuits so I'm not interested in that solutions)!

Thanks in advance!


Mr.Cube

 

[hugo]

Hi,

I'm not going to say it is the best ... but check it out :

MCP23017/MCP23S17

# 16-bit input/output port expander with interrupt output
# Cascadable for up to 8 devices on one bus
# 25mA sink/source capability per I/O
# Supports up to 10MHz SPI™ clock speeds

https://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en023500

 

[wp100]

Hi,

Why not use a 40 pin Pic chip which has 35 available i/os, if thats not enough for your needs then move on to the smd 64 pin chips which are hand solderable - could always try the 100 pin chips if you need that many.

Alternatively use 2 pic chips talking to each other which should increase your i/o speed.

 

[nandhu015]

What about serial in parallel out shift registers?

Nandhu

 

[bassa]

Hi,

How about MAXIM

**broken link removed**?
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regards
bassa