PH Tester With Display Accuracy 0.01

LilyPad Arduino USB - ATmega32U4 Board
LilyPad Arduino USB is an ATmega32u4-based microcontroller board. It has nine digital input / output pins (four of which are available as PWM outputs and four as analog inputs), an 8 MHz resonator, a micro USB connection, a JST connector for a 3.7 V LiPo battery, and a reset Button.
It contains everything you need to support your microcontroller; simply connect it to your computer with a USB cable or boot it with a battery.