INTRODUCTION

In the previous lessons, we introduced the ultrasonic obstacle avoidance robot and infrared obstacle avoidance ro. In order to avoid obstacles more accurately, in this lesson we combined an ultrasonic module and an infrared obstacle detector sensor to build an obstacle avoidance robot.

PREPARATION

Hardware:

● 1 X USB cable

● 1 X micro:bit robot

CODE PROGRAM

Then the micro:bit is connected to the computer through USB, and the computer will pop up a U disk and click the URL in the U disk to enter the programming interface. Input this URL https://github.com/osoyoo/OSOYOO-MICRO-BIT-CAR to get the package.

RUNNING RESULT

①When the front obstacle distance measured by ultrasonic sensor is greater than 15cm.

• If detects an obstacle on the left side but not on the right side, the car will turn right at a certain angle then go forward.
• If detects an obstacle on the right side but not on the left side, the car will turn left at a certain angle then go forward.
• If detects no obstacle at both sides, the car will go forward.
• If detects obstacles at both sides, the car will stop, robot car goes backward, after 100ms, turns left at a certain angle and then goes forward.

②When the front obstacle distance measured by ultrasonic sensor is less than or equal to 15cm.

• If detects an obstacle on the left side but not on the right side, the car will turn right at a certain angle then go forward.
• If detects an obstacle on the right side but not on the left side, the car will turn left at a certain angle then go forward.
• If detects no obstacle at both sides, the car will turn left at a certain angle then go forward.
• If detects obstacles at both sides, the car will goes backward, after 100ms, turns left at a certain angle and then goes forward.

Note:

This experiment must be carried out indoors to reduce interference from sunlight to infrared receiver.

If the robot tracking is not normal, you can adjust its speed and running time through makecode, and you can also change the sensitivity of the infrared obstacle avoidance sensor by adjusting the potentiometer