Hello,

I have a robot which uses a Me Auriga, equivalent to an Arduino Mega2650 board, and 180 optical encoder motors. On the Me Auriga board, I have uploaded the following Arduino firmware CreativeBottypeA_firmware . I am using rosserial_python on my Raspberry Pi 3+

RPi Terminal

 rosrun rosserialpython serialnode.py 

I am trying to publish odometry information using encoder ticks on Arduino. If I'm right, We can do this by two ways :

1. Publishing left and right encoder ticks from Arduino so that the Rpi subscribe and use them to publish odom message on RPi (Python)
2. Publishing odom message from Arduino using the encoder ticks (I would like to do this). Could you please help me?

1. Arduino A few lines of the robot's firmware :

#include 


include 

include 

include 

include "MeAuriga.h"

MeOnBoardTemp OnBoardTemp(PORT13);
MeEncoderOnBoard Encoder1(SLOT1);
MeEncoderOnBoard Encoder_2(SLOT2);

ros::NodeHandle  nh;

stdmsgs::Int16 leftticksmsg;
stdmsgs::Int16 rightticksmsg;

ros::Publisher publeftticks("/leftticks",&leftticksmsg);
ros::Publisher pubrightticks("/rightticks",&rightticksmsg);

long ticks_time;

void lwheelvtarget(const stdmsgs::Float32& vel){
  if(motorOn){
    Encoder2.runSpeed(vel.data);
  }
  else {
    Encoder2.runSpeed(0);
  }
}

void rwheelvtarget(const stdmsgs::Float32& vel){
  if(motorOn){
    Encoder1.runSpeed(-vel.data);
  }
  else {
    Encoder1.runSpeed(0);
  }
}

void isrprocessencoder1(void){
  if(digitalRead(Encoder1.getPortB()) == 0){
    Encoder1.pulsePosMinus();
  }
  else {
    Encoder_1.pulsePosPlus();;
  }
}

void isrprocessencoder2(void)
{
  if(digitalRead(Encoder2.getPortB()) == 0)
  {
    Encoder2.pulsePosMinus();
  }
  else
  {
    Encoder2.pulsePosPlus();
  }
}
ros::Subscriber<stdmsgs::Float32> subleft("lwheelvtarget", &lwheelvtarget);
ros::Subscriber<stdmsgs::Float32> subright("rwheelvtarget", &rwheel_vtarget);

void setup()
{
  /* Encoder motor drives */
  attachInterrupt(Encoder1.getIntNum(), isrprocessencoder1, RISING);
  attachInterrupt(Encoder2.getIntNum(), isrprocessencoder2, RISING);

//Set PWM 8KHz
  TCCR1A = _BV(WGM10);
  TCCR1B = _BV(CS11) | _BV(WGM12);

TCCR2A = _BV(WGM21) | _BV(WGM20);
  TCCR2B = _BV(CS21);

Encoder1.setPulse(9);
  Encoder2.setPulse(9);
  Encoder1.setRatio(39.267);
  Encoder2.setRatio(39.267);
  Encoder1.setPosPid(0.18,0,0);
  Encoder2.setPosPid(0.18,0,0);
  Encoder1.setSpeedPid(0.18,0,0);
  Encoder2.setSpeedPid(0.18,0,0);
  Encoder1.runSpeed(0);
  Encoder2.runSpeed(0); 
  Encoder1.setMotionMode(PIDMODE);
  Encoder2.setMotionMode(PIDMODE);

nh.getHardware()->setBaud(115200);
  nh.initNode();
  nh.advertise(publeftticks);
  nh.advertise(pubrightticks);
  nh.subscribe(subleft);
  nh.subscribe(subright);
}

void loop()
{

    // publish wheel pos in ticks for each wheel
  if(millis() >= tickstime){
    leftticksmsg.data = Encoder2.getPulsePos();
    publeftticks.publish(&leftticksmsg);
    rightticksmsg.data = Encoder1.getPulsePos();
    pubrightticks.publish(&rightticksmsg);
    tickstime = millis()+10;
  }
  if(!motorOn){
    Encoder1.runSpeed(0);
    Encoder2.runSpeed(0);
  }
  Encoder1.loop();
  Encoder2.loop();
  nh.spinOnce();
  delay(100);
}
}

Thank you, :)

Shanika