Digital I/O Pins 14 (of which 6 provide PWM output)Analog Input Pins 6
Does it mean the arduino can handle 14 devices at a time?
QuoteDoes it mean the arduino can handle 14 devices at a time?It depends on what you're attaching to it. If you just want to turn relays on and off, it's actually 20 because you can use the Analog pins as digital ones. Some items, such as an LCD may take more pins to operate them. If you need more, you can use external multiplexing hardware, or you can buy a Mega - more memory and more pins.Compared to the speed that things happen in a house automation environment, the Arduino is phenomenally fast. You should not have any problem with it keeping up if you code correctly. i.e. don't use the delay function for anything more than tiny debounce (or the like) delays.
What we would need is a very small switch mode PSU, say, the size of a small relay. Does something like this exist?