How to interface Arduino Mega 2650

I need help with interfacing my 2650 with more than one external project.
I've connected up the Memsic 2125.
I've connected up a ball mouse.
I've connected up almost all of the examples and more.

Here is my issue.

How do I make a ball mouse do something like move a SERVO or activate an LED?
How do I make a Memsic 2125 move a SERVO or turn on an LED?
How do I make a PlayStation DualShock2 move a SERVO or turn on an LED?

Thank you

r u familiar with the procedural programming paradigm?

u can gather data X from an input device
compute some new configuration data Y using X
then u reconfigure an output device to Y


i meant this:

did u try a simple program:
maybe one that reads a character from the Serial object
and then echoes it to the Serial object?

void setup() {

void loop() {
int c =;
// here u can add some cool modification...
// e. g.:
// c += 9 - c%9;

Could you please help me some more? Could you give me specific examples that I can save and use to modify? I would really appreciate it.

Thank you,


u will find some examples especially for beginners...

have fun... :wink: