as a 63 year old i know nothing about programming.i want to purchase an arduino but which one? i see uno r3, mega , mega with android?????? now leonardo. to get the best possible experiance out of my arduino plus value for money,so i dont want to buy cheap then want another shortly.any help is welcome.......mally
mega with android? Isn't that the Due with ARM processor? It's another level of hardware complexity above the 8-bit AVR's used by the UNO, Leonardo and Mega2560.
With a Mega2560 you will take 4x longer to run out of RAM, it has 8k RAM and 128k Flash. You can store text and tables in flash with your program. Using tables is a great way to speed up calculation/decision-intensive code greatly. Flash stored text has loads of uses, you could save a novel and still have room for a program to present it on a screen.
Mega2560's got 44 pins with 3 hardware serial channels and whole ports with 8 bits clear of other use by default, each is capable to be an 8-bit bi-directional parallel port. With UNO the answer is to add chips on a breadboard. You won't run out of those as soon.
It's got some other "run out later than sooner" aspects.
A not terribly-down-side is there are more examples for the UNO and UNO owners are more common, you're more likely to get help on UNO-whatever.
If you can run it on an UNO, you can usually run it on a Mega after changing some pin numbers and other hardware-oriented values whereas if it runs on a Mega there's no guarantee it will ever run on an UNO.
That said the Mega2560 is standard and simple yet powerful enough to be desired.
I started out wanting to program standalone chips. To me my UNO is a development board, a tool to make other AVR-things with. I've done it to test that I could, but still learning power and sensors and different pieces that can be used because they interest me.
If your eyes are like mine, they need help getting a wire end in the right hole when the holes are 10 to the inch. I followed Grumpy_Mike's advice and got a magnifier visor.
I got the Cadillac model down at Harbor Freight with the 4 double-lens set and led light. With my 40% off coupon it ran 6 bucks. I use the 2nd thickest set of lenses and I'm seeing little things like I could when I was a kid. Small print is no barrier. The wire goes in the right hole and I'm sure of it.
With the visor, the lens is always in place. With the visor on, you can use both hands.
Another thing they have is compartment storage trays with hinged, locking covers. Without coupon, $4 each. They're big and flat and 20-some compartments. Remember those and where they are. They're better than pulling parts out of labeled bags to set up for a project, the nooks are big enough to hold labels viewable. If it wasn't for those labels it'd take me 10x longer to find the right, for example, value resistor.
Old books on C apply. In the early years of C, computers had very limited RAM. Learn C first, then C++. C++ happened when standard PC's had lots of RAM which Arduinos do not. Some C++ is better not used on 8-bit Arduinos, like using C++ Strings as opposed to C strings. You'll see.