Modern Robotics Ultrasonic and Optical Range Sensor Reading between 1cm and 255cm Standard 4 pin connector: For connection to I2C port Mounting holes: 48x24mm / Wire length: 25cm Power: 5 VDC. 20 mA max. The Modern Robotics Ultrasonic and Optical Range Sensor (1-255cm) combines ultrasonic and optical measuring elements to obtain a reading between 1cm and 255cm. The ultrasonic sensor accurately measures the distance to a target up to 255cm away, but it losses accuracy if the object is closer than 5cm. This is where the optical sensor comes into play as it can measure from 1cm out to about 7cm. The target shape and surface material will influence the detectable range. Built in a robust plastic housing with either a three or four wire connector for easy connection to various Modern Robotics Controllers. The target shape and surface material will influence the detectable range. These sensors are designed for work, play and education with a housing tailored to fit the Matrix Robotics System’s 8mm grid.