[sdiy] mcu project with too few I/O lines :(

[John Speth]

Use 74HCT595's if you're short on outputs.  Use 74HCT165's if you're short
on inputs.

John Speth
Coherent Molectron
mailto:john.speth at coherentinc.com

> -----Original Message-----
> From: Bert Schiettecatte 
> [mailto:bert.schiettecatte at esat.kuleuven.ac.be]
> Sent: Friday, May 23, 2003 11:24 AM
> To: synth-diy at dropmix.xs4all.nl
> Subject: [sdiy] mcu project with too few I/O lines :(
> 
> 
> hi all,
> 
> i'm doing a microcontroller project here with an optrex graphical 
> display (128x64), rotary encoder, led matrix (16 leds), and key 
> matrix (16 keys). of course there is also the midi and in system 
> programming connectors. unfortunately my microcontroller (atmega8) 
> does not have a lot of i/o lines available, and I'm left clueless 
> how to interface all that stuff to it. The display has an 8bit 
> data bus + a few i/o lines for reading, writing, etc. for the 
> led matrix, i'd like brightness control for each led (PWM?). 
> 
> I thought about using a key encoder and maybe an LED driver but 
> those ICs are pretty expensive (7$ for a key encoder, that's more 
> than a microcontroller!). does anyone have some advice here and 
> how to interface this stuff without buying tons of additional ICs 
> which cost a lot of $$$?
> 
> thanks,
> bert
> 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20030523/e42f84d8/attachment.htm>