Sundowner
Start with an Arduino....
See if you NEED a Pi even...
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If you want video = pi
If you want some real time audio processing = pi (Arduino can do playback..but thats getting to the limits)
90% of my projects are most Arduino based
I have done a couple Pi projects as well (although not really props).
* Mini Arcade cabinet/emulator
* MQTT server (broker) for home automation stuff (along with fully installed LAMP/Apache, MySQL, PHP for logging and other web related needs)
* Barbot.. although the PI is really just being used for the touchscreen interface (drink menu) to send out the 'recipe' via serial to the Arduino that does all the serial parsing, servo and stepper work...etc
IMHO... the drawbacks are:
1.) size (most props need the smallest electronics to fit)
2.) price.. outside of the odd 30% deal the last week or so at Arrow.. I have never saw a RPi for under $35.00 (EVER!)... so its not always cost effective/efficient to spend $35 on a PI and shove it in a prop permanently each time... (plus I'd bet most of the time its overkill to use a Pi)
Doesnt compare when you can spend $3.00 USD for a Pro-Mini and forget about it.. You really need to decide if you NEED a Pi (the power)..