The Ultrasonic Ranging Module provides stable readings and accurately measures distance. This module can be used for a number of projects such as fluid level in a tank, distance to obstacles, and other sensing tasks. KEY FEATURES Working voltage : 5V(DC) Static current: Less than 2mA. Output signal: Electric frequency signal, high level 5V, low level 0V. Sensor angle: Not more than 15 degrees. Detection distance: 2cm~450cm. High precision: Up to 3mm Mode of connection: VCC / trig(T) / echo(R) / GND NOTES Initiate IO trigger by supplying at least 10us high signal The module automatically sends eight 40khz square waves and detects the returning pulse signal if available Unlike in the photos, a 25 cent coin is not included LINKS Download - http://www.ic5188.com/PDF/HC-SR04.rar Interrupt-driven C code for ODROID-C0/C1/C1+ with Python example - https://github.com/OtherCrashOverride/hc-sr04 ODROID Forum post discussing this module - http://forum.odroid.com/viewtopic.php?f=55&t=18793&sid=18a943e0a9f67e4459dea756cdaf8109#p125 Warranty is valid for two weeks, starting upon date of receipt.