Testing in procedural programming code

Question

I have designed and implemented, for my final year in college, an autonomous robot with Arduino board microcontroller. The robot wanders around an area, avoids obstacles and tries to detect intruders.

I have to do some testing for this project . Could anyone help me by telling what test procedures I can perform in procedural code?

Observation of the behavior of robot could be one of them?

Servo servoLeft; // Define left servo
Servo servoRight; // Define right servo
const int trigPin = 5;
const int echoPin = 2;
int buzzerPin = 6; // choose the pin for the LED //buzzer
int inputPin = 9; // choose the input pin (for PIR sensor)
int val = 0; 
Timer t;
boolean pirSense = false;
long xronos=0;
void setup() { 
Serial.begin(9600);
 servoLeft.attach(4); // Set left servo to digital pin 10
 servoRight.attach(3); // Set right servo to digital pin 9
 pinMode(buzzerPin, OUTPUT); // declare LED as output
 pinMode(inputPin, INPUT); // declare sensor as input
 pinMode(trigPin, OUTPUT);
 pinMode(echoPin, INPUT);
 t.every(30000,monitoring);
 } 
 void loop() { 
 long duration, distance;
 digitalWrite(trigPin, LOW);
 delayMicroseconds(2);
 digitalWrite(trigPin, HIGH);
 delayMicroseconds(10);
 digitalWrite(trigPin, LOW);
 pinMode(echoPin, INPUT);
 duration = pulseIn(echoPin, HIGH);
 distance = microsecondsToCentimeters(duration);
 delay(100);
 Serial.println(distance);
 if (distance >= 40){
 moveForward();
 }
 else {
 stopMove();
 int x = random(0,2); 
 if(x == 0 ){ 
 turnRight(); 
 delay(500);
 }
 else{
 turnLeft(); 
 delay(500);
 }
 }
 t.update();
 }
 void monitoring(){
 xronos = now();
 while( xronos+5 >now() ){
 stopMove();
 delay(1000);
 pirSensor();
 }
}
 // Motion routines for forward, reverse, turns, and stop
 void reverse() {
 servoLeft.write(0);
 servoRight.write(180); 
 }
 void moveForward() {
 servoLeft.write(180);
 servoRight.write(0);
 }
 void turnRight() {
 servoLeft.write(180);
 servoRight.write(180);
 }
 void turnLeft() {
 servoLeft.write(0);
 servoRight.write(0);
 }
 void stopMove() {
 servoLeft.write(90);
 servoRight.write(90);
 }
 long microsecondsToCentimeters(long microseconds)
 {
 // The speed of sound is 340 m/s or 29 microseconds per centimeter.
 // The ping travels out and back, so to find the distance of the
 // object we take half of the distance travelled.
 return microseconds / 29 / 2;
 }

• Useless: Do you have pure (side-effect-less) procedures? If so, you can write regular unit tests for those.
• Useless: I mean functions which take arguments, return results, and don't modify any global variables or other external state (ie, they don't move the robot, print a string, etc.)
• alexca: I have only one function that takes an argument and return something into the main program. All the others are void type. Also i have 2 global variables that could change their value!
• Robert Harvey: The term you're looking for is "unit testing." You unit test methods by calling them and seeing if they return the expected value, or modify the expected variables.
• alexca: You think that i could say something about observation of the behavior of the robot for the testing?

Answer 1

Observation of the robot is probably the most important test you can run. Don't let anyone tell you that anything short of a full integration test (which is what your observation is) is fully testing.

However, there are also unit testing frameworks for Arduino.

There are also Pseudo-Arduino boards.

And there are also ways to do pseudo-object-oriented C, to allow you to test your objects independently.

All of these will probably serve you well in a variety of contexts. Understand your options and pick the best tool for the job; that's the skill of programming.

But never forget that there's no better testing than watching the totality of your code work as it's intended. That applies as much to writing a web page, or a game or a robot controller.

• alexca: Thanks for your answer! For the pseudo-Arduino in perl i downloaded the file from github. Now i have to downolad some IDE for perl in order to run it?
• pdr: @user2250119: perl.org/get.html