BAB V HASIL DAN PEMBAHASAN
5.2 Komunikasi Serial Menggunakan Rosserial
ex1 = 1.85 - 1.813 = 0.037 lokasi 2:
ex2 = xm2 – xe2
ey2= 2.87 - 2.835 = 0.035 lokasi 3:
ex3 = xm3 - xe3; ey3 = ym3 - ye3;
ex3 = 2.17 - 2.167 = 0.003 ey3 = 1.90 - 1.933 = -0.033
Keterangan : xm = Nilai pengukuran manual pada sumbu x xe = Nilai terukur Indoor GPS pada sumbu x ym= Nilai pengukuran manual pada sumbu y ye= Nilai terukur Indoor GPS pada sumbu y xe= Nilai perhitungan error
#!/usr/bin/env python import rospy
from rosserial_python import SerialClient, RosSerialServer from serial import SerialException
from time import sleep import multiprocessing import sys
if __name__=="__main__":
rospy.init_node("serial_node")
rospy.loginfo("ROS Serial Python Node")
port_name = rospy.get_param('~port','/dev/ttyUSB0') baud = int(rospy.get_param('~baud','57600'))
# for systems where pyserial yields errors in the fcntl.ioctl(self.fd, TIOCMBIS, \
# TIOCM_DTR_str) line, which causes an IOError, when using simulated port
fix_pyserial_for_test = rospy.get_param('~fix_pyserial_for_test', False) # Allows for assigning local parameters for tcp_port and fork_server with
# global parameters as fallback to prevent breaking changes if(rospy.has_param('~tcp_port')):
tcp_portnum = int(rospy.get_param('~tcp_port')) else:
tcp_portnum =
int(rospy.get_param('/rosserial_embeddedlinux/tcp_port', '11411'))
if(rospy.has_param('~fork_server')):
fork_server = rospy.get_param('~fork_server') else:
fork_server =
rospy.get_param('/rosserial_embeddedlinux/fork_server', False)
# TODO: do we really want command line params in addition to parameter server params?
sys.argv = rospy.myargv(argv=sys.argv) if len(sys.argv) >= 2 :
port_name = sys.argv[1]
if len(sys.argv) == 3 :
tcp_portnum = int(sys.argv[2]) if port_name == "tcp" :
server = RosSerialServer(tcp_portnum, fork_server)
rospy.loginfo("Waiting for socket connections on port %d" % tcp_portnum)
try:
server.listen()
except KeyboardInterrupt:
rospy.loginfo("got keyboard interrupt") finally:
rospy.loginfo("Shutting down")
for process in multiprocessing.active_children():
rospy.loginfo("Shutting down process %r", process) process.terminate()
process.join()
rospy.loginfo("All done") else : # Use serial port while not rospy.is_shutdown():
rospy.loginfo("Connecting to %s at %d baud" % (port_name,baud) ) try:
client = SerialClient(port_name, baud, fix_pyserial_for_test=fix_pyserial_for_test)
client.run()
except KeyboardInterrupt:
break
except SerialException:
sleep(1.0) continue except OSError:
sleep(1.0) continue except:
rospy.logwarn("Unexpected Error: %s", sys.exc_info()[0]) client.port.close()
sleep(1.0) continue
Node Subscriber Pada Arduino
/*
* rosserial Subscriber Example * Blinks an LED on callback */
#define USE_USBCON
#include <ros.h>
#include <std_msgs/Int32.h>
#define STEP_PIN1 5 // Connect the driver's step pin to pin 5
#define DIRECTION_PIN1 6 // Connect the driver's direction pin pin 6
#define STEP_PIN2 7 // Connect the driver's step pin to pin 5
#define DIRECTION_PIN2 8 // Connect the driver's direction pin pin 6
#define VRM1 22
#define CW1 23
#define VRM2 26
#define CW2 27
#define RUN2 28
#define BERHENTI 0
#define MAJU 1
#define MUNDUR -1
#define MAJUKANAN 2
#define MAJUKIRI 3
#define MUNDURKANAN -2
#define MUNDURKIRI -3
#define PUTARKANAN 4
#define PUTARKIRI -4 int keadaan;
ros::NodeHandle nh;
void messageCallback(const std_msgs::Int32& cmd_msg) { int cmd = cmd_msg.data;
switch (cmd) {
case BERHENTI: keadaan = BERHENTI; berhenti(); break;
case MAJU: keadaan = MAJU; maju(); break;
case MUNDUR: keadaan = MUNDUR; mundur(); break;
case MAJUKANAN: keadaan = MAJUKANAN; maju(); break;
case MAJUKIRI: keadaan = MAJUKIRI; maju(); break;
case MUNDURKANAN: keadaan = MUNDURKANAN; mundur(); break;
case MUNDURKIRI: keadaan = MUNDURKIRI; mundur(); break;
case PUTARKANAN: keadaan = PUTARKANAN; belokKanan(); break;
case PUTARKIRI: keadaan = PUTARKIRI; belokKiri(); break;
default: break;
} }
ros::Subscriber<std_msgs::Int32> sub("turtle_control", &messageCallback);
void setup() {
pinMode(LED_BUILTIN, OUTPUT);
nh.initNode();
nh.subscribe(sub);
pinMode(STEP_PIN1, OUTPUT);
pinMode(DIRECTION_PIN1, OUTPUT);
pinMode(STEP_PIN2, OUTPUT);
pinMode(DIRECTION_PIN2, OUTPUT);
pinMode(VRM1, OUTPUT);
pinMode(CW1 , OUTPUT);
pinMode(RUN1, OUTPUT);
pinMode(VRM2, OUTPUT);
pinMode(CW2 , OUTPUT);
pinMode(RUN2, OUTPUT);
keadaan = BERHENTI;
}
void belokKanan() {
delay(10);
digitalWrite(RUN2, LOW);
delay(10);
digitalWrite(CW2, LOW);
delay(10);
digitalWrite(RUN2, LOW);
digitalWrite(VRM2, LOW);
}
void belokKiri() {
delay(10);
digitalWrite(RUN2, LOW);
delay(10);
digitalWrite(CW2, LOW);
delay(10);
digitalWrite(RUN2, LOW);
digitalWrite(VRM2, LOW);
}
void berhenti() {
delay(10);
digitalWrite(RUN2, LOW);
delay(10);
digitalWrite(CW2, LOW);
delay(10);
digitalWrite(RUN2, LOW);
digitalWrite(VRM2, LOW);
}
void maju() {
delay(10);
digitalWrite(RUN2, HIGH);
delay(10);
digitalWrite(CW2, HIGH);
delay(10);
digitalWrite(RUN2, LOW);
digitalWrite(VRM2, HIGH);
}
delay(10);
digitalWrite(RUN2, HIGH);
delay(10);
digitalWrite(CW2, LOW);
delay(10);
digitalWrite(RUN2, LOW);
digitalWrite(VRM2, HIGH);
}
void loop() {
switch (keadaan) { case BERHENTI:
break;
case MAJU:
MoveStepsKanan(4, 1000);
MoveStepsKiri(-4, 1000);
break;
case MUNDUR:
MoveStepsKanan(-4, 1000);
MoveStepsKiri(4, 1000);
break;
case MAJUKANAN:
MoveStepsKanan(4, 1000);
MoveStepsKiri(-8, 1000);
break;
case MAJUKIRI:
MoveStepsKanan(8, 1000);
MoveStepsKiri(-4, 1000);
break;
case MUNDURKANAN:
MoveStepsKanan(-4, 1000);
MoveStepsKiri(8, 1000);
break;
case MUNDURKIRI:
MoveStepsKanan(-8, 1000);
MoveStepsKiri(4, 1000);
break;
case PUTARKANAN:
MoveStepsKanan(-4, 1000);
MoveStepsKiri(-4, 1000);
break;
case PUTARKIRI:
MoveStepsKanan(4, 1000);
MoveStepsKiri(4, 1000);
break;
}
nh.spinOnce();
delay(1);
}
void MoveStepsKanan(int steps, unsigned int microsecondStepDelay)
{
if (steps < 0){
digitalWrite(DIRECTION_PIN1, LOW); // Set counter-clockwise direction }else{
digitalWrite(DIRECTION_PIN1, HIGH); // Set clockwise direction }
// Moves desired number of steps
// Motor rotates one step when STEP_PIN changes from HIGH to LOW for(int i = 0; i < abs(steps); i++){
digitalWrite(STEP_PIN1, HIGH);
delayMicroseconds(microsecondStepDelay/2);
digitalWrite(STEP_PIN1, LOW);
delayMicroseconds(microsecondStepDelay/2);
} }
void MoveStepsKiri(int steps, unsigned int microsecondStepDelay) {
if (steps < 0){
digitalWrite(DIRECTION_PIN2, LOW); // Set counter-clockwise direction }else{
digitalWrite(DIRECTION_PIN2, HIGH); // Set clockwise direction }
// Moves desired number of steps
// Motor rotates one step when STEP_PIN changes from HIGH to LOW for(int i = 0; i < abs(steps); i++){
digitalWrite(STEP_PIN2, HIGH);
delayMicroseconds(microsecondStepDelay/2);
digitalWrite(STEP_PIN2, LOW);
delayMicroseconds(microsecondStepDelay/2);
} }
Dengan menggunakan Rosserial dapat membuat komunikasi yang lancar antara perangkat keras mikrokontroler dan sistem ROS, memungkinkan untuk mengendalikan dan memonitor robot atau sistem lain secara lebih terstruktur dan terintegrasi. Langkah awal untuk membuat komunikasi serial dengan menjalankan program serial_node atau node yang akan memfasilitasi untuk melakukan komunikasi serial yang ditampilkan Gambar 5.9.
Gambar 5.13 Program Serial Node
Dengan menjalakan kedua program maka akan muncul topik dengan nama turtle_control seperti yang ditampilkan pada Gambar 5.10 dimana subscribernya adalah program pada ardunino.
Gambar 5.14 Komunikasi Serial menggunakan Rosserial