Embedded Arduino

Greetings everybody! I want to hardwire an arduino into e.g. a toy or other device. My plan is to write a sketch, load it onto a new 386 chip and then insert this chip into a cut down board with only those components needed for running the sketch. Any reprogramming of the chip would be done by transferring the chip back to my normal Arduino board. I therefore need some guidance on how to make the cut down board. Obviously the USB connection hardware will not be needed unless I write a script that needs to write to serial. Also not needed are the on-board LEDs. The crystal and associated components are obviously essential as are the chip socket and pin connections, but I don't have sufficient knowledge to work out what else is needed. Has anybody gone this route and if so, have you a circuit diagram for such a board or can you suggest a possible source? I would use a perforated strip boards for the purpose. Regards to all. Grumps

Look up "standalone Arduino" for more info. Note one thing: The DIP IC socket on the Arduino is -not- designed for repeated plugging and unplugging; if you plan on doing this a lot, I would reccommend looking into hooking up a ZIF (zero insertion force) socket in place of or external to the regular DIP IC socket.

If you are careful with what you connect to the SPI pins, you will be able to reprogram the processor place...

The crystal and associated components are obviously essential

The processor has an internal oscillator that allows it to run without the crystal + capacitors (or resonator). The tradeoff is that it is less accurate than a crystal.

cr0sh:
The DIP IC socket on the Arduino is -not- designed for repeated plugging and unplugging...

I'd certainly be willing to believe that, it's always a bit of an ordeal with those 28-pin sockets. I usually try to work slowly from both ends. Do the manufacturers specify a maximum number of insertion/extraction cycles? I looked at a couple random datasheets but didn't see anything. I use ZIF sockets on a couple target boards and they are certainly the way to go if you need to program a bunch of chips or whatever.

Well I have changed 328p chips in one of my arduino boards at least 100 times and have seen no problems so far. I did get a 28 pin DIP ZIP socket and a small minimum standalone board to make kind of a programming fixture assembly to use with my USBtiny programmer:

Lefty

This is the best stand-alone arduino tutorial I've seen:

http://itp.nyu.edu/physcomp/Tutorials/ArduinoBreadboard

Besides crystals and capacitors, you need a circuit to regulate power so arduino gets a constant 5V from any power source, 9V battery or ac adapter, so 3 more parts. I would not suggest you start with internal oscillator. That's just extra step that you could mess up. A crystal and a couple of capacitors aren't going to take too much space or money. If you want to commercialize your design and minimize parts, or wants to reduce frequency to save battery, you can do internal oscillator. Just snip off the external crystal and hope you understand how to use internal oscillator.