I'm still very green to all this but I've made a few projects and am starting to wonder about permanent installed units without using up one of my Unos. I've found instructions to make an Arduino out of an AtMega328 chip, 22uF capacitors, a 16Mhz crystal and various other parts. However, in some videos for other projects I'm interested in doing they use the 328 chip without all of the other components featured on the the Arduino.
Do I actually need to build an Arduino with all the parts or can I just use the 328 chip and program it via the Arduino Uno I have? I need to cut down the size of the unit for my next project, so running just the 328 would really help.
Of course you only need the parts for your particular project. If you do not need it to "talk" to a PC, you do not need the USB interface. You need to have the power sourced by a 5V regulator or a battery of lesser voltage (a 3.5V lithium or 3 AA cells). If you want maximum performance, you need the crystal and 22pF capacitors, otherwise you can program the chip to use its internal 8 MHz clock (which you would need to do to operate at 3.5V, or use an 8 MHz crystal). You rarely need a power indicator (and it is annoyingly bright), and you only need whatever LEDs you require for indicators - or not. You probably do not need a reset switch for a stand-alone unit - though it might be useful if you propose to have it "sleep" when not in use (you can use it as both the power on and power off switch!).
On the other hand, if you do need the regulator and 16 MHz crystal, you are probably better off using a "Pro Mini" (clone) which has these components, uses the smaller chip, and little else.
Thanks, thats pretty much answered everything I wanted to know! The project is literally making a repeating led display so it doesn't need to be overly robust, so after programing the 328 I should be good
You need clean power and a couple of bypass caps. Everything else is up to your app.
If you can wire it all up to a socket then you don't even need a board.
It's the app that can change everything.
