is arduino support the 2 devices like volume of the speaker and power outlet? pls help me to answer this.
Almost certainly - you've got 20 IO pins to control, and 32k of flash space to fit the code into, 2k of RAM - that's almost always enough to control well over two devices. It of course depends on how the interface with those device you're controlling works, as well as how the Arduino gets told to do it's thing.
Right now your question is really really vague. What kind of power outlet? Mains voltage or low voltage DC? You have to be extremely careful with mains voltage, since it can cause serious damage to persons or property.
What kind of volume control? How is it controlled now?
How does the arduino decide to when to switch the power or change the volume?
I often use much smaller (fewer pins, less memory) arduino-compatible chips than the ones in the official boards to control multiple devices each.
DrAzzy:
I often use much smaller (fewer pins, less memory) arduino-compatible chips than the ones in the official boards to control multiple devices each.
DrAzzy, I've used 8-pin PIC12F509 chips for this in the past, prior to starting with Arduino, (I'm a newbie to Arduino), but would be interested in an example or two of small Arduino-compatible chips if you don't mind. I'd like to check them out.
OldSteve:
DrAzzy, I've used 8-pin PIC12F509 chips for this in the past, prior to starting with Arduino, (I'm a newbie to Arduino), but would be interested in an example or two of small Arduino-compatible chips if you don't mind. I'd like to check them out.
In referring to the Attiny series, like the ones the cores I maintain (in Sig) support...
DrAzzy:
In referring to the Attiny series, like the ones the cores I maintain (in Sig) support...
Thank you for that. Exactly the type of thing I was thinking of, but a lot more guts than the PIC12F509 that I usually use. Even a 4-channel ADC, I see. I'll have to buy a few. (And learn how to program them etc.)
I'd heard of the ATtiny, but didn't realise it used an 8-pin chip.