Confessions of a FPV pilot. The rover - Part 2

I'm going to explain the first version of the Arduino sketch to control the rover with a web browser.

Arduino sketch has the goal to receive some commands from the web server and drive the servos according to commands. To do that I use the Bridge library to read commands from web server and Servo Library to drive the servos.
The Arduino Yùn board has:

• "Arduino" microcontroller 
• micro PC on which "Linux run" and a web server . 
• wifi board.

I wrote the following Arduino sketch starting from the Bridge and Servo library that you can read here and here.

//include the library

#include <Bridge.h>
#include <YunServer.h>
#include <YunClient.h>
#include <Servo.h>

//comunication server declaration with the Linux side 
YunServer server;

//Servo objects declarations 
Servo myservoL;
Servo myservoR;

//function mode variable (forward, left, right, stop)
int mode; 
//timeout variable to avoid run without commands
int timeout;

//Arduino setup routine
void setup() {
//servo pins declaration
  myservoL.attach(9);
  myservoR.attach(10);

//variables initialization
  mode=0;
  timeout=0;

//set pin13 for debug function
  pinMode(13,OUTPUT);

//start Bridge comunication with Linux
  Bridge.begin();
  server.listenOnLocalhost();
  server.begin();
}

void loop() {
  digitalWrite(13, HIGH);
  //read commands from Linux
  YunClient client = server.accept();
   if (client) {
   //if there is a message it tries to decode
    process(client);
    client.stop();
  }
  //select actions to do according to current "mode" variable
  if (mode == 1) {
    gostraight();    
  }
  if (mode == 2) {
    turnleft();
  }
  if (mode == 3) {
    turnright();
  }
  if (mode == 4) {
    stopmode();
  }
  //strobe alive led
  digitalWrite(13, LOW);
  //slow is better
  delay(50); 
}

void process(YunClient client) {
  String command = client.readStringUntil('/');
  if (command == "mode") {
   //if it's a "mode" command 
    modeCommand(client);
  }
  if (command == "state") {
   //if it's a "state" command
    stateCommand(client);
  }
}

void modeCommand(YunClient client) {
//change the function mode
  mode = client.parseInt();
  if (client.read() == '/') {
   //set new timeout for the new function mode
    timeout = client.parseInt();
  }
  //answer with current function "mode" and "timeout"
  client.print(mode);
  client.print(F("#"));
  client.print(timeout);
  client.println("");
}   

 //answer with current function "mode" and "timeout"
void stateCommand(YunClient client) {
  client.print(mode);
  client.print(F("#"));
  client.print(timeout);
  client.println("");
} 

//exec go forward command mode
void gostraight() {
  if (timeout > 0) {
    myservoL.write(-180);
    myservoR.write(180);
    timeout = timeout -1;
  }
  else {
    stopmode();  
  }
}

//exec turn left command mode
void turnleft() {
  if (timeout > 0) {
    myservoL.write(180);
    myservoR.write(180);
    timeout = timeout -1;
  }
  else {
    stopmode();  
  }
}

//exec turn right command mode
void turnright() {
  if (timeout > 0) {
    myservoL.write(-180);
    myservoR.write(-180);
    timeout = timeout -1;
  }
  else {
    stopmode();  
  }
}

//exec stop command mode
void stopmode() {
    myservoL.write(90);
    myservoR.write(90);
    timeout = 0;
    mode=0;  
}

In the next post I will talk about the web server Linux.