From 6a43957bd67e4e354db22f141a0eb3d20aca363f Mon Sep 17 00:00:00 2001
From: Denis Zheleztsov <d_zheleztsov@wargaming.net>
Date: Wed, 21 Nov 2018 16:13:53 +0300
Subject: [PATCH] Random turn

---
 car.ino | 64 +++++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 44 insertions(+), 20 deletions(-)

diff --git a/car.ino b/car.ino
index 62e9b6b..aec1dd7 100644
--- a/car.ino
+++ b/car.ino
@@ -1,5 +1,8 @@
 #include <hcsr04.h>
 
+/* constans */
+/* ******** */
+
 /* Define your pins here */
 /* Wheels */
 const int left_wheel_1  = 0;
@@ -11,36 +14,33 @@ const int right_wheel_2 = 3;
 const int sensor_echo    = 9;
 const int sensor_trigger = 10;
 
+/* Other constans */
+const int move_delay = 500;
+const int turn_delay = 500;
+
+/* disconnected pin for random seed */
+const int analog_disconnected = 0;
+
+/* Initialize sensor class */
 HCSR04 hcsr04(sensor_trigger, sensor_echo, 20, 4000);
 
 /* Array bellow contains all the wheels */
 int wheels[] = {left_wheel_1, left_wheel_2, right_wheel_1, right_wheel_2};
 
-/* The counter */
-int i;
-
-int mm;
-
-/* Ultrasonic sensor variables */
-long duration;
-int distance;
-
 void setup() {
   /* Setup pins */
   /* wheels */
-  for (i = 0; i < sizeof(wheels) - 1; i++) {
+  for (int i = 0; i < sizeof(wheels) - 1; i++) {
     pinMode(wheels[i], OUTPUT);
   }
 
-  /* Ultrasonic sensor */
-  pinMode(sensor_echo, INPUT);
-  pinMode(sensor_trigger, OUTPUT);
-
   /* Starts serial communication */
   Serial.begin(9600);
+  Serial.println("Bot is ready");
 }
 
 /* Wheel actions */
+/* ************* */
 
 /* Forward */
 void move_forward_wheel_left() {
@@ -56,6 +56,7 @@ void move_forward_wheel_right() {
 void move_forward() {
   move_forward_wheel_left();
   move_forward_wheel_right();
+  delay(move_delay);
 }
 
 /* Backward */
@@ -72,11 +73,12 @@ void move_backward_wheel_right() {
 void move_backward() {
   move_backward_wheel_left();
   move_backward_wheel_right();
+  delay(move_delay);
 }
 
 /* Stops */
 void stop_all() {
-  for (i = 0; sizeof(wheels) - 1; i++) {
+  for (int i = 0; sizeof(wheels) - 1; i++) {
     digitalWrite(wheels[i], LOW);
   }
 }
@@ -104,11 +106,22 @@ void turn_right(int delayMS) {
   delay(delayMS);
 }
 
+void turn_left_or_right(int delayMS) {
+  randomSeed(analogRead(analog_disconnected));
+  int rand_number = random(1, 99);
+  if (rand_number > 50) {
+    turn_right(delayMS);
+  } else {
+    turn_left(delayMS);
+  }
+}
+
 /* Ultrasonic sensor actions */
+/* ************************* */
 
 /* get_distance -- returns distance to an object in centimeters */
 int get_distance() {
-  mm = hcsr04.distanceInMillimeters();
+  int mm = hcsr04.distanceInMillimeters();
   if (mm > 0) {
     return mm / 10;
   }
@@ -116,14 +129,25 @@ int get_distance() {
 }
 
 /* Main code */
+/* ********* */
+
+/* The idea:
+
+   If robot see an object in distance less than 25cm,
+   he must do the following actions:
+
+     * stop the wheels
+     * turn on wheels to go backward for 1 second
+     * stop wheels
+     * turn left or right
+     * then go forward
+*/
 void loop() {
   if (get_distance() > 25) {
     move_forward();
-    delay(1000);
   } else {
-    turn_left(500);
+    stop_all();
     move_backward();
-    delay(1000);
-    turn_right(500);
+    turn_left_or_right(turn_delay);
   }
 }