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Topic: Not Enough Analog Out pins (Read 741 times) previous topic - next topic

urthlight

I am using the adafruit 2.8 TFT display and it uses all of the analog pins except 42, 44 and 46 so I am using one pin(44) for all four of the motor controllers. I would really like each to have its own signal. Can this be done some other way?

AlxDroidDev


I am using the adafruit 2.8 TFT display and it uses all of the analog pins except 42, 44 and 46 so I am using one pin(44) for all four of the motor controllers. I would really like each to have its own signal. Can this be done some other way?


You have 3 available output pins, and that's excellent news!

You can wire a 74HC595 to those 3 pins and that will give you 8 output signals. In short, you'll communicate serially with the 595 (thus the need for only 3 pins) and it will give you 8 parallel outputs, or, in other words, the 595 will work as a port multiplexer.

More here:

http://arduino.cc/en/Tutorial/ShiftOut

http://www.instructables.com/id/Multiplexing-with-Arduino-and-the-74HC595/

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urthlight

I only have 3 analog outputs left but a lot of digital pins.

AlxDroidDev


I only have 3 analog outputs left but a lot of digital pins.


I am a bit lost here... what do you mean?

AFAIK, analog outputs are simply digital pins. They are the same thing.
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Showing off my work: http://arduino.cc/forum/index.php/topic,126197.0.html

Coding Badly

I am using the adafruit 2.8 TFT display...


This?
https://www.adafruit.com/products/376

Coding Badly

I am a bit lost here... what do you mean?


"Analog pin" = pin capable of PWM output.

AlxDroidDev


"Analog pin" = pin capable of PWM output.


Ok... my bad then. I always called them PWM pins. For me the analog pins are the input pins, since the PWM pins are digital.
Learn to live: Live to learn.
Showing off my work: http://arduino.cc/forum/index.php/topic,126197.0.html

urthlight

Exactly. I read somewhere about Pseudo pwm on a digital pin but I dont know.

urthlight

But this is a small issue on the butt of a larger problem.

Motor Acceleration Timer Deceleration Problem
http://arduino.cc/forum/index.php/topic,162373.msg1213468.html#msg1213468

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