Hello I'm new with android and I want to know if anyone know how to link or connect arduino with android or how can I make an app that show me in my cellphone the values that the arduino is reading, I don't know if anyone have a tutorial or can help me, thanks.
There is no standard solution for Arduino + Android.
Android Debug Bridge, MCU+USB Host, covers all Android Phone, but 4.2+ requires RSA authentication.
Android Open Accessory, MCU+USB Host, covers all Android 4.0 Phone
Android USB host API, covers all MCU + CDC/ACM bridge, but only popular in tablet, since most of low end Android phones have not OTG hardware.
Android Bluetooth, depends on profiles and BL4/BLE support
Android WiFi, MCU requires WiFi module and TCP/IP stack.
NFC, not all Android phones have NFC and MCU....
So far, I have three boards, one LPC812+CP2102/Arduino 2009, can talks to Android via USB CDC. The other is GAP, based upon FRDM-KL25Z128, has on-board USB host to talk with Android over ADB.
You might want to see some of my projects involving interfacing arduino and android.
I use MIT's appinventor to create apps (very easy to do - watch the second video to see how it's done)
There are two methods for communication - one that relies on bluetooth communication and one based on ethernet
I posted it here on arduino forum -> http://forum.arduino.cc/index.php/topic,148853.0.html