The MB1242 rangefinder from MaxBotix is an inexpensive I²C-based ultrasonic (sonar) sensor that can provide distances between 20mm and 765mm. Likes its UART-based MB1240 sibling, it is the sonar unit that MaxBotix recommends for use on Unmanned Aerial Vehicles. Because I like to work with this and others sensors on a variety of platforms (Arduino, RasperryPi, NVIDIA Jetson), I've written a little library that will allow you to use the MB1242 on any of these platforms, CrossPlatformDataBus, which you will need to clone into your Arduino/libraries folder as well.

The MB1242 library provides a simple API for reading distance in centimeters from the MaxBotix MB1242 I²C sensor. Although the datasheet for this sensor indicates an operating voltage of 3-5.5V, I've had the most success with it by powering the microcontroller from an external power supply.

I have tested this library on the following hardware:

• Teensy 3.2 development board

• Raspberry Pi 3

• NVIDIA Jetson TX1