If you want to connect your sensor using Android phone, then IOIO board could be the simple solution for it. The IOIO (pronounced “yo-yo”), a PIC-based board designed to work with Android device (OS versions 1.5 and greater). The board provides robust connectivity to an Android device via a USB connection and is fully controllable from within an Android application using a simple and intuitive Java API – no embedded programming or external programmer will ever be needed.
The IOIO board contains a single PIC MCU that acts as a USB host and interprets commands from an Android app. In addition, the IOIO can interact with peripheral devices in the same way as most MCUs. Digital Input/Output, PWM, Analog Input, I2C, SPI, and UART control can all be used with the IOIO. Code to control these interfaces is written in the same way as you write an Android app with the help of a simple to use app-level library.
Starting at Bootloader V3.0 + App V3.10, IOIO can communicate with your Android device over Bluetooth connection. This is achieved simply by attaching a standard Bluetooth dongle into the USB jack on the IOIO board. The IOIO now has beta firmware available which supports Google’s Open Accessory (ADK) protocol.