Introduction

We used the components from previous tutorials to create a radar.

We combined the circuits from previous tutorials. Our circuit looks similar to the diagram below:

Arduino

Code explanation

Setup

We define the nesessary variables and objects and initialize the objects just like in previous lessons.

Loop function

In the loop() function we sweep the servo and perform the measurements. To avoid having duplicate code, we call another function.

Measure and send

In the measureDistance() function we

1. Set the servo angle
2. Measure the ultrasonic distance
3. Turn LED on/off according to the distance
4. Send the current angle and distance to Serial

Processing

Code explanation

Draw Radar Outline

This function draws the arcs and lines for the radar. We also print the angles and distances.

Draw Scanning Line

Draws the scanning line for the current angle.

Draw Detected object

If an object is detected a line is drawn from the corrent distance on the radar.

Draw Information

The current angle and distance are printed.

Fade

Draws a semi-transparent black background to hide old values.

Push/Pop Matrix

pushMatrix() saves current transformation.

popMatrix() restores the last transformation.

Translate

translate(x, y) moves the coordinate system

The coordinate system in Processing begins in the top-left corner of the screen. The x value increases to the right. The y value increases to the bottom.

Radar Running

Exercise

Display a text when an object is currently detected.

Challenge

Add any functionality to the radar or build something creative yourself!