Running out of Pins

Forum 2005-2010 (read only) Hardware Interfacing
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Hello, bit of an arduino noobie here looking for some guidance on an upcoming project. I have a project that requires me to drive a small 3VDC motor, play a sound and flash some LEDs. Due to time and budget constrains, Im trying to use as many pre-made kits as possible, so that I dont have to spend a lot of time de-bugging my own mistakes.

I figured for audio I can use the adafruit wav shield, the motor will be controlled by a L293D motor driver and the LEDs can just be driven by the digital outputs. The only problem is Im running out of pins.

The wav shield uses all digital pins but 6, 7, 8, 9. The motor driver will use 6,7,9 leaving me with only the analog inputs and out digital I/O. Im not really familar with how I would drive multiple LEDs from only one output?

Also is it possible to use the Analog inputs as digital inputs, so that you dont have to spend the extra resources for the analog conversion? I have a few inputs which would work just fine if I could use the analog inputs to simply monitor whether or not they had a voltage on them, regardless of what it actually was.

And lastly, what may circumvent this whole problem, is there a different kit for making the arduino play music which would use less pins than the wav shield?

Thanks soooo much!

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Shields use predefined pins. If you have at least 2 pins (data + clk) free, you can use a shift register for driving leds.

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You can use the analogue pins as digital in or out just use Digital pins 14 - 19 (analogue 0 - 5).

I have 3 leds blinking away merrily now on what officially are Analogue 3, 4 and 5.

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so that I dont have to spend a lot of time de-bugging my own mistakes.

Those are the only sort of mistakes you will be debugging. :wink:

Welcome to the wonderful world of embedded systems where all errors are entirely your own, either in implementation or understanding.