Which board to use?

Projects General Guidance
1

I am planning a security system with a 16x2 LCD display, a 4x4 matrix switch and a solenoid. But the number of I/O pins are not sufficient for the project. Now which basic board should I use??

2

Mega 2560 ??

3

You could offload 4 I/0 to the 16u2 on a Uno. Or the Leonardo has separate SPI pins, not 11,12 and 13. So that gives you 3 more pins. Shift registers can be used for LCDs.

4

SagarDev:
I am planning a security system with a 16x2 LCD display, a 4x4 matrix switch and a solenoid. But the number of I/O pins are not sufficient for the project. Now which basic board should I use??

get a serial display.
use a serial 4x4 matrix and you can get an UNO and have lots of pins to spare.