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Topic: logic high == +5v ? (Read 417 times) previous topic - next topic

robvoi

Hi,

I bought a Pololo A4988 stepper driver to configute microstepping I need to bring some pins to logig high or logic low (which they are in by default).
I can simply connect them to +5V? Or is there a difference between bringing them to high via a digital PIN and connecdting them to +5V rail?


Thanks
Robert

CrossRoads

Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

robvoi

Thanks. Just wanted to make sure I don't fry the driver.

Robert

MarkT

Nearly all modern stuff is CMOS, and CMOS logic levels go right to the rails.  (This wasn't true
for older TTL logic families which used pull-up resistors for logic high)
[ I won't respond to messages, use the forum please ]

CrossRoads

CMOS uses transistors to pull the outputs low or to drive them high also.
http://www.ti.com/lit/an/scla007a/scla007a.pdf
See figures 2 & 3 on pages 1 & 2.
Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

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