Chief Delphi - Controlling robot with arduino

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Controlling robot with arduino

Hi,
I am trying to control one of our old robots with arduino. But I really don't know where to begin. Arduino UNO has 6 PWM pins to which I can connect the victors. But I am not sure how I can control with joysticks. Could you please give me some clue?

Re: Controlling robot with arduino

It is doable, but requires much more effort than its worth.

First, you'd need to get an Arduino Ethernet Shield to connect the Arduino to an ip network.

You'd then need to write a client application that controls the robot, along with sending the joystick button states, axis values, and other data to the arduino, over the network. (Not as easy as it sounds)

You'd also need to write a program for the arduino that SAFELY gets the values from the computer (joystick and control mode: disabled or enabled), and uses them to set the values of victors/spikes/solenoids/etc... Be sure to implement important safety features like having the robot automatically disable when communication is lost, not driving out of control, etc.

It's a long process, and can be a great learning experience. IF you're looking for a quick and easy way to get an old robot running, this is not the way to do it.

Feel free to contact me if you want more details or have any questions.

Re: Controlling robot with arduino

First off, this is a great project! I would definitely suggest you do this. It's not anything that hasn't been done before so you should find plenty of information in a quick Google search (remember there is nothing really different between the FRC robot and a robot someone made in their workshop using RC car components - the building blocks are the same. You may want to look at ArduRover and ArduPilot.

There are actually some products readily available to help, such as this shield that interfaces with the digital sidecar <http://www.andymark.com/product-p/am-2258.htm>

I assume you will simply be replicating what the FRC control system does on this old robot, so I would suggest to first list out all the motors, motor controllers, sensors, spike relays and the method which they are controlled in software (PID loop, PWM, Meccanum drive, tank drive, etc.) This will help you build a plan for the pins and the coding.

From there on out, you will be tackling each subsystem: drive, manipulator/shooter/scoring/collecting device, and any other features of the robot in code. I'd focus on getting it controlled one motor controller at a time and work up to more complex loops as your skill increases.

Are you using pneumatics?

Re: Controlling robot with arduino

An Arduino Motor Shield will help, too.

Arduino site: http://arduino.cc/en/Main/ArduinoMotorShieldR3
Ladyada tutorial: http://www.ladyada.net/make/mshield/
Sparkfun's version: https://www.sparkfun.com/products/9815

Re: Controlling robot with arduino

This is not a hard challenge! Check out our RobotOpen driver station app...

www.robotopen.biz

Our HTML5 app will allow you to read USB gamepads and directly control your Arduino board. It offers two way communications, data logging, live parameters and a host of other features.

Free open-source download.

We have shields as well if you'd like to interface with an existing digital sidecar or pneumatics bumper.

Re: Controlling robot with arduino

Quote:

Originally Posted by ThaDeanesta (Post 1264702)

First, you'd need to get an Arduino Ethernet Shield to connect the Arduino to an ip network.

Alternatively, you can get a cheap RC plane controller with a receiver that outputs PWM signals.

Re: Controlling robot with arduino

Quote:

Originally Posted by Roger (Post 1264730)

A motor shield will not be useful for anything FIRST related. The speed controllers communicate using PWM

Re: Controlling robot with arduino

Quote:

Originally Posted by mman1506 (Post 1264916)

The speed controllers communicate using PWM

Specifically "hobby servo PWM".

Re: Controlling robot with arduino

There is a USB Host shield for the Arduino. There are 3rd party library's available that would allow a wireless PlayStation 3 controler to work with the arduino. This would give a minimal blue tooth connection to the arduino for control.

Re: Controlling robot with arduino

Quote:

Originally Posted by toyalima (Post 1264696)

I have yet to order one but these look promising http://www.team221.com/robotopen/product.php?id=105

Re: Controlling robot with arduino

Like I stated above, you only need our RobotOpen Control Shield if you want to continue using your digital Sidecar.

Some features will be lost of course, but in general our driver station app will perform as expected using just an Ethernet enabled Arduino.

Re: Controlling robot with arduino

You can do this cheaply and easily... you just have to think outside the cRio/FRC "box" a bit. I currently have a small "fleet" of vehicles running using Victor 888 controllers and CIM motors attached to Arduino Unos. It works great, and is quite easy to do... I've etched custom shields to attach the speed control pins and joystick (or bluetooth) connections, but you could do this easily enough using a breadboard, and then solder it up onto some perfboard/protoboard. I did have to recalibrate the Victors, as the Arduino was giving me slightly longer pulses than expected, but that is really easy to do... just push the "calibration" button on the Victor and move the joystick full circle to give "max" and "min" signals to the Victor, then let go of the stick.

Here's some code for controlling Victors on Pin8 and Pin9 using "joystick" mode, from a joystick connected to A2 and A3. The code will also print the values to your serial monitor. The downside is that it requires a joystick to be wired to your uno/robot at all times. (Which, in the application we have, where the driver is sitting on the vehicle... works great!)

Code:

#include <Servo.h> //include the Servo library for controlling the Victor speed controls



Servo motor_l;     //left motor servo object will be attached to pin 8

Servo motor_r;     //right motor servo object will be attached to pin 9

const int joy1_x = 2;   //the first joystick's x axis will be on analog input A2

int joy1_x_val;            // the value that we read from joystick 1's x axis

const int joy1_y = 3;   //the first joystick's y axis will be on analog input A3

int joy1_y_val;            // the value that we read from joystick 1's y axis

const int joy1_sw = 3;   //the first joystick's switch will be on digital input 3

const int led = 13;      //an led indicator to show whats going on (there should be one on the arduino board)

int left_motor;      //the value between 0 (full reverse) and 180 (full forward) to send to the left motor

int right_motor;      // the value to send to the right motor (90=stop)



void setup () {

  motor_l.attach(8); //attach the servo object to the correct digital output pins

  motor_r.attach(9);

  

  Serial.begin(9600);

  

  pinMode (led,OUTPUT);

  pinMode (joy1_sw,INPUT_PULLUP);

  digitalWrite (led,HIGH);

  delay (250);

}



void loop () {

  joy1_x_val=map (analogRead(joy1_x),0,1023,0,180); //read the joystick's analog value (0-1023)

  joy1_y_val=map (analogRead(joy1_y),0,1023,0,180); //and map it to the servo range of (0-180)

  left_motor= (joy1_y_val - joy1_x_val)+90;          // then mix the signals for "one stick drive"

  right_motor= (joy1_y_val + joy1_x_val)-90;

  motor_l.write(left_motor);                        //assign the resulting values to the servo pins

  motor_r.write(right_motor);

  

  Serial.print("Joy1x:");

  Serial.print(joy1_x_val);

  Serial.print("\t");

  Serial.print("Joy1y:");

  Serial.print(joy1_y_val);

  Serial.print("\t");

  Serial.print("Left Motor:");

  Serial.print(left_motor);

  Serial.print("\t");

  Serial.print("Right Motor:");

  Serial.println(right_motor);

  

  digitalWrite (led,digitalRead(joy1_sw));

  

  delay (10);

  

}

But this is the code I really like... purchase a bluetooth serial dongle, and connect it to pin0 and pin1 on the Arduino. (Note that you'll have to remove the dongle when programming the Arduino.) The download BlueBots to your Android phone. Pair your phone to the dongle, run BlueBots and you've got wireless control of your robot... from your phone.

By the way, you can get BlueBots Pro for $1.65... definitely worth it to support the developer considering that you'll replace about $1,000 of robot control equipment with a $30 Arduino, $10 bluetooth dongle and an Android phone that you may already own.

Code:

#include <Servo.h>



Servo motorL;

Servo motorR;

int motorLspeed;

int motorRspeed;



int joyX=0;

int joyY=0;

int slide1=0;

int slide2=0;

int checksum=0;

int double_check=0;





unsigned long last_time=millis();

void setup () {

  Serial.begin(9600);

  motorL.attach(8);

  motorR.attach(9);

}

// Read the data packed from Bluebot's joystick mode

void loop () {

  if (Serial.available()>0) {

    double_check=0;

    if (Serial.read()==125) { //125 indicates a joystick packet

      joyX=Serial.read(); // type mismatch issues occur

        if (joyX>128) joyX=joyX-256; //so make sure we get the negatives correct

      joyY=Serial.read();

        if (joyY>128) joyY=joyY-256;

      slide2=Serial.read();

      slide1=Serial.read();

      checksum=Serial.read(); //see Bluebots help file for checksum

      double_check=(125+joyX+joyY+slide1+slide2)%256;

      last_time=millis();

    }

  }

 // Timeout routine to stop motors if signal is lost for 500ms

 // also stops the motors if the checksum indicates lost data

 // This section would be better if I used 2x oversampling and

 // only killed the motors if two checksums in sequence were flawed

 // This section can be commented out, but it does play a safety role

 // in the event that Bluetooth communication is lost

  if ((millis()-last_time)>500||(checksum!=double_check)){

   joyX=0;

   joyY=0;

   slide2=62;

   slide1=62;

   if (millis()-last_time>500)Serial.println("Time Out");

   if (checksum!=double_check)Serial.println("Checksum Error");

  }

  

  // Map and send motor outputs

  motorLspeed=joyY-joyX;

  motorLspeed=map(motorLspeed,-124,124,0,180);

  motorLspeed=constrain(motorLspeed,0,180);

  

  motorRspeed=joyY+joyX;

  motorRspeed=map(motorRspeed,-124,124,0,180);

  motorRspeed=constrain(motorRspeed,0,180);

  

  motorL.write(motorLspeed);

  motorR.write(motorRspeed);

  

  delay(10);

  

/* Debugging print routine

  Serial.print("X");

  Serial.print(joyX);

  Serial.print(" Y");

  Serial.print(joyY);

  Serial.print(" S1 ");

  Serial.print(slide1);

  Serial.print(" S2 ");

  Serial.print(slide2);

  Serial.print(" Chk ");

  Serial.print(checksum); 

  Serial.print(" DblChk ");

  Serial.print((double_check));

  Serial.print(" MotL ");

  Serial.print(motorLspeed);

  Serial.print(" MotR ");

  Serial.println(motorRspeed);

  delay(100);

//*/  

}

And remember to keep your fingers away from the motors and chains/belts when experimenting!

Jason

Re: Controlling robot with arduino

Highly recommend the Romeo robotic controller board. It supports XBee devices, so all you need is this device as a remote controller. All up, Romeo, controller, 2 - Xbees and battery sets will be $175.

Re: Controlling robot with arduino

6 weeks ago I saw AndyMark had the Arduino kit for $130 and now they have sold out. Could this possibly replace the CRio?

Re: Controlling robot with arduino

I have just purchase one of this arduino from AnyMark and I have done all the programming and I am ready to test it on a robot that we have design and pour our personal money. My question is how can you attached a solenoid? Would you hook it on the relay ports on the sidecard? or would you use a spike to operate the solenid, we are using 12V solenoids. Also I though about using this cheap relays that we use at my school for simple projects but the coil is rated at 12VDC as well and as far as I know the sidecard can put out a max of 5V.