I don't know which board to use for my project.

Projects General Guidance
1

I want to make an external keyboard for my android phone and I don't know which board to use for my project.

I have thought of Arduino Mega ADK because in its information page it is written that "It has a USB host
interface to connect with Android based phones" and because it has many pins too, so maybe it is the right choice.

But when I saw the keyboard functions in the example sections in the website, like (KeyboardMessage or KeyboardSerial) it says the functions only support Arduino Leonardo, Micro, or Due boards, that's made me think of Arduino Due because it has many pins and it supports the keyboard functions but I'm not sure if it can be connected to an android phone.

I really dont know which board to buy. I dont want to buy the Arduino Mega ADK and then find out that it wont work with a keyboard function or the Arduino Due the find out I cant connect it to my phone.

Is there any advice about which board to use for my project?

2

Hi, welcome to the forum.

Grab an USB keyboard and connect that to the phone.
The Logitech K120 can be bought for about 10 euros.

An Arduino Leonardo/Micro/Due can be just like a USB keyboard.
http://arduino.cc/en/Reference/MouseKeyboard

The Arduino Mega ADK is specific to connect to an Android App.

If you need a lot of pins, the Arduino Due can be like an USB keyboard to a computer or phone. That will work. You can buy the Arduino Leonardo to test everything and buy the Arduino Due when you are sure you want to continue this project.

How many keys will there be ? What kind of keys ?

3

Hi Peter

Thanks for your help.

So if I want to make an external keyboard and use it with android apps like faceook or whatsapp I should use the Due board, right ??

And if I use the Due board the 3.3V instead of the 5V is not going to be a problem, right ??

I need 52 pins for the letters and the special characters. About

Peter_n:
What kind of keys ?

if you mean what kind of keys will I use, I will use push buttons as keys.

4

The 3.3V is no problem. The USB part of the Due is 5V.

52 pins ? A keyboard is almost always used in a matrix.
This is a library that scans the matrix : Arduino Playground - HomePage
Do you have an old keyboard ? if you open it, you can see how simple it is.

5

Thanks a lot.

I will check it now.