Please excuse any ignorance, i've only read some tutorials and have never used an Arduino device of any kind. I have been using a raspi for almost 6 months. I'm trying to decide whether raspberry pi or arduino would be better suited to complete the following. (I guess this group will be a little prejudice - - ha ha)
Project idea:
Push a button to start a timer and light an led at different intervals, Green for 60, seconds, then switch to Yellow and stay on for 2 min, then switch to a Red, and stay on for 2 min. At the same time be able to play a simple wave or mp3 file.
Power needs to be internal, device will need to be switched off when not in use to conserve battery.
arduino with sd card reading shield and get a midi player library... arduino would use less power compared to a rasp pi also i find it easier to code .
The Arduino does need an additional shield (add-on board) to store and play audio files. But, the buttons & LEDs are easy.
I don't think the Raspberry Pi has any general-purpose I/O ports/pins, so the buttons & LEDs might require something additional, but playing and storing sounds should be easy.
Doing this on Raspi or Arduino will be straightforward.
The Raspi can do it without any external hardware (other than the leds and resistors) - the Pi has a few GPIO pins available, as I understand.
The Arduino could do it easily - except for the playing of the MP3, for which you need an MP3 player module . These can be had ( a number of different modules are available, some of them incredibly cheap on ebay, which play MP3's off a microSD card).
If you're already comfortable programming something like that on the Pi, I'd definitely consider using the Pi for it, since it's not something that's inherently "harder" on the pi, and may even be easier, since you don't need the external hardware for the audio.
DVDdoug:
I don't think the Raspberry Pi has any general-purpose I/O ports/pins, so the buttons & LEDs might require something additional,
Not at all. The Raspberry Pi has a bunch of GPIO (General Purpose Input Output) pins. They're not 5V tolerant but buttons and LEDs are easy on the R Pi.
This is something that should be perfectly practical on an RPi and there will be a huge saving in time if you can build on your existing knowledge of the Pi.
I would only use an Arduino if you specially want a project as a basis for learning about Arduinos. However, compared with an RPi playing music on an Arduino is difficult and likely to be poor quality.