Can anyone explain these codes to me?
[code]#include <SoftwareSerial.h>
#include <Wire.h>
#include <LSM303.h>
LSM303 compass;
LSM303::vector<int16_t> running_min = {
-1383, -2061, -3033}
, running_max = {
2229, 1974, 1206};
#define triggerZ 8
#define echoZ 9
#define ultrasonic_power 7
SoftwareSerial mySerial(2, 3); // RX, TX
int cx, cy;
unsigned long prevTime= millis();
unsigned long currTime;
unsigned long elapTime;
void setup() {
Serial.begin(9600);
mySerial.begin(9600);
pinMode(triggerZ, OUTPUT);
pinMode(echoZ, INPUT);
pinMode(ultrasonic_power, OUTPUT);
digitalWrite(ultrasonic_power, HIGH);
Wire.begin();
compass.init();
compass.enableDefault();
}
void loop() {
// if(calc_x() < -50 || calc_x() > 50){
// Serial.println(calc_x());
// }
//
// if(calc_y() < -50 || calc_y() > 50){
// Serial.println(calc_y());
// }
//
// currTime = millis();
// elapTime = currTime - elapTime;
// if(elapTime > 100){
// mySerial.print(calc_x());
// mySerial.print(’\n’);
// mySerial.print(calc_y());
// mySerial.print(’\n’);
// prevTime = millis();
// }
Serial.print(calc_x());
Serial.print(’\t’);
Serial.println(calc_y());
while(mySerial.available()){
if(mySerial.read() == 49){
mySerial.print(calc_x());
mySerial.print(’\n’);
mySerial.print(calc_y());
mySerial.print(’\n’);
}
}
// mySerial.print(calc_x());
// mySerial.print("\t");
// mySerial.print(calc_y());
// mySerial.print("\t");
// mySerial.println(calc_z());
//
}
int calc_x(){
compass.read();
int x;
x = compass.a.y;
// 0 - 1000, 0 -100 //
return(map(x, -16500, 16500, -250, 250));
}
int calc_y(){
compass.read();
int y;
y = compass.a.x;
return(map(y, -16500, 16500, -250, 250));
}
int calc_z() {
long duration, distance;
digitalWrite(triggerZ, LOW);
delayMicroseconds(2);
digitalWrite(triggerZ, HIGH);
delayMicroseconds(10);
digitalWrite(triggerZ, LOW);
duration = pulseIn(echoZ, HIGH, 12000);
distance = (duration / 2) / 29.1;
if (duration >11640){
distance = 200;
}
return (distance);
}
void send_data(){
mySerial.print(cx);
mySerial.print(cy);
}
void print_raw(){
Serial.print(calc_x());
Serial.print(’\t’);
Serial.print(cx);
Serial.print(’\t’);
Serial.print(calc_y());
Serial.print(’\t’);
Serial.println(cy);
}[/code]