Robot obstacle avoidance demo - VL6180X

Testing proximity sensors and control algorithm. The VL6180X time-of-flight distance sensors worked great for this demo. They function very reliably against a wide range of target surfaces and respond quickly (in this demo, 20Hz). By using separate reset lines for each chip, I was able to chain 3 of them on one I2C bus. The motors are driven by a TB6612 which provides excellent efficiency and low voltage drop. In this way, I am able to power the drive motors from a mere 5 volts.