PlotJuggler

PlotJuggler github

Install

ROS Package

# The install method from snap include ROS2, zmq, websocket and MQTT
sudo snap install plotjuggler
#
#sudo apt install ros-humble-plotjuggler-ros

---

Plugins

Websocket

code

pip install websocket-client

import websocket
import math
import json
from time import sleep
import numpy as np


ws = websocket.WebSocket()
ws.connect("ws://localhost:9871")


time = 0.0

while True:
   sleep(0.05)
   time += 0.05
   print(time)
   data = {
       "timestamp": time,
       "test_data": {
           "cos": math.cos(time),
           "sin": math.sin(time),
           "floor": np.floor(np.cos(time)),
           "ceil": np.ceil(np.cos(time))
       }
   }

   ws.send(json.dumps(data))

Usage

Config plotjuggle to websocket listener that get json data

---

ZMQ

code

pip install websocket-client

import zmq
import math
import json
from time import sleep
import numpy as np


context = zmq.Context()
serverSocket = context.socket(zmq.PUB)
port = 9872
serverSocket.bind("tcp://*:"+str(port))
time = 0.0
while True:
   sleep(0.05)
   time += 0.05
   print(time)
   data = {
       "timestamp": time,
       "test_data": {
           "cos": math.cos(time),
           "sin": math.sin(time),
           "floor": np.floor(np.cos(time)),
           "ceil": np.ceil(np.cos(time))
       }

   }

   serverSocket.send_string(json.dumps(data))

usage

---

MQTT

Prerequisites

Install mqtt broker on ubuntu machine

sudo apt install mosquitto mosquitto-clients

sudo systemctl status mosquitto

Test mqtt broker

• Without authentication

mosquitto_sub -t "hello/topic"

mosquitto_pub -t 'hello/topic' -m 'hello MQTT'

Install

sudo snap install plotjuggler

Python code

Python code

pip install paho-mqtt numpy

import paho.mqtt.client as mqtt
import math
import json
from time import sleep
import numpy as np

# MQTT Broker details
BROKER = "localhost"  # Change to your MQTT broker address
PORT = 1883  # Default MQTT port
TOPIC = "sensor/data"  # MQTT topic to publish data

# Create MQTT client
client = mqtt.Client()
client.connect(BROKER, PORT, 60)

time_counter = 0.0

while True:
    sleep(0.05)  # 50 ms sleep for 10 Hz
    time_counter += 0.05  # Increment time

    # Create data payload
    data = {
        "timestamp": time_counter,
        "test_data": {
            "cos": math.cos(time_counter),
            "sin": math.sin(time_counter),
            "floor": np.floor(np.cos(time_counter)),
            "ceil": np.ceil(np.cos(time_counter))
        }
    }

    # Convert to JSON and publish
    client.publish(TOPIC, json.dumps(data))
    print(f"Published: {data}")

usage