Help with code analysis

Projects Programming
1

Hi guys,

I've recently received the code below but I can't quite figure out what each part does. From what I know of the project the are 4 motors that control forward/backward movement and 2 that control cables that would change the direction of the robot.
Here are the picture of what it looks like turning and the code:
Thanks in advance for any help.
http://imageshack.com/a/img843/7775/68k9.png

#include <MeetAndroid.h>





int drivePWM = 130;    
int rearPWM = 130;   
int steerPWM = 130; 

int adjustedPWM = 0;
int adjustedRearPWM;
int adjustedSteerPWM;

int MotorPin1 = 6;
int MotorPin2 = 5;


int rearMotorPin1 = 9;
int rearMotorPin2 = 10;

int steerMotorPin1 = 13;
int steerMotorPin2 = 11;
      
MeetAndroid meetAndroid;
void setup()
{
  // start serial port at 9600 bps:
  Serial1.begin(115200);
  Serial.begin(115200);
  
  meetAndroid.registerFunction(get_drive, 'o');
  meetAndroid.registerFunction(get_steer, 'p');
  meetAndroid.registerFunction(get_rear, 'q');
                                                                                              

}

void loop()
{
  meetAndroid.receive();
    
     
  //set drive PWM
  if (drivePWM > 140){
    adjustedPWM= map(drivePWM, 140, 255, 0, 200);
    
    analogWrite(MotorPin1, adjustedPWM);
    analogWrite(MotorPin2, 0);
  }
  else if (drivePWM < 120){
    adjustedPWM = map(drivePWM, 0, 120, 200, 0);
    analogWrite(MotorPin2, adjustedPWM);
    analogWrite(MotorPin1, 0);
  }
  else{
    analogWrite(MotorPin1, 0);
    analogWrite(MotorPin2, 0);
  }
  
  
  //rear PWM
  if (rearPWM > 140){
    adjustedRearPWM = map(rearPWM, 140, 255, 0, 150);
    analogWrite(rearMotorPin1, adjustedRearPWM);
    analogWrite(rearMotorPin2, 0);
  }
  else if (rearPWM < 120){
    adjustedRearPWM = map(rearPWM, 0, 120, 150, 0);
    analogWrite(rearMotorPin2, adjustedRearPWM);
    analogWrite(rearMotorPin1, 0);
  }
  else{
    adjustedRearPWM = 0;
    analogWrite(rearMotorPin1, 0);
    analogWrite(rearMotorPin2, 0);
  }
  
  
 
  //steer PWM    
  
  if (steerPWM > 140){
    adjustedSteerPWM = map(steerPWM, 140, 255, 0, 150);
    analogWrite(steerMotorPin1, adjustedSteerPWM);
    analogWrite(steerMotorPin2, 0);
  }
  else if (steerPWM < 120){
    adjustedSteerPWM = map(steerPWM, 0, 120, 150, 0);
    analogWrite(steerMotorPin2, adjustedSteerPWM);
    analogWrite(steerMotorPin1, 0);
  }
  else{
    analogWrite(steerMotorPin1, 0);
    analogWrite(steerMotorPin2, 0);
  }  
  
  
  
  
  
  delay(50);
  
}


void get_drive(byte flag, byte numOfValues)
{
  drivePWM = meetAndroid.getInt();
}

void get_steer(byte flag, byte numOfValues)
{
  steerPWM = meetAndroid.getInt();
}

void get_rear(byte flag, byte numOfValues)
{
  rearPWM = meetAndroid.getInt();
}
2

Are you asking us to add the comments that you are supposed to add before you post any code ?

3

and there is some lib needed ....

4

I don't know where you got the code from but they are the people you need to ask . And you need to get the libraries too.

5

This is too vague a question, and you are probably not going to get very helpful answers until you get more specific. I don't think anybody here is likely to walk you through the code, line by line.

6

the main code is missing calls to get_steer() etc, so the PWM values never change.