Theara Seng

Theara Seng

Electronics, IoT, Robotics

ESP32 → MQTT → Node-RED → InfluxDB → Grafana Dashboard

ESP32 → MQTT → Node-RED → InfluxDB → Grafana Dashboard

This project demonstrates a complete IoT data pipeline using an ESP32 running MicroPython, sending random sensor values via MQTT to Node-RED, which stores the data in InfluxDB and visualizes it in Grafana.

🧭 Contents

ESP32 (MicroPython)

└── publishes random ints → MQTT topic: /aupp/esp32/random

└── MQTT broker (test.mosquitto.org:1883)

└── Node-RED (MQTT In → Function → InfluxDB Out)

└── InfluxDB (measurement: random, field: value, tag: device)

└── Grafana (InfluxQL queries + auto refresh)

⚙️ Prerequisites

Hardware

  • ESP32 board (any variant supporting MicroPython)

Software

Optional Tools

⚙️ Installing Node-RED (Local Setup)

Node-RED is a flow-based tool for wiring together hardware, APIs, and online services — perfect for IoT projects like this one.

🧩 Option 1 — Install via npm (recommended for Windows, macOS, Linux)

📦 Node-RED requires Node.js ≥ 14 and npm installed first.
Download Node.js from https://nodejs.org.

  1. Open Terminal (macOS/Linux) or PowerShell (Windows).
  2. Install Node-RED globally:
    
npm install -g --unsafe-perm node-red
  3. Start Node-RED
    
node-red
  4. Once started, open your browser and go to:
    
http://localhost:1880

    🗄️ Installing InfluxDB (v1.x)

InfluxDB is a time-series database used to store sensor and IoT data efficiently.

💡 This project was tested with InfluxDB v1.12.2 (InfluxQL syntax).
Official downloads: https://portal.influxdata.com/downloads/

🧩 Windows Installation

  1. Open PowerShell as Administrator and start the server:
    wget https://download.influxdata.com/influxdb/releases/v1.12.2/influxdb-1.12.2-windows.zip -UseBasicParsing -OutFile influxdb-1.12.2-windows.zip

    Then

    Expand-Archive .\influxdb-1.12.2-windows.zip -DestinationPath 'C:\Program Files\InfluxData\influxdb\'
  2. In a PowerShell window, open the Influx shell:
    cd "C:\Program Files\InfluxData\influxdb"
.\influxd.exe
  3. In a new PowerShell window, open the Influx shell:
    cd "C:\Program Files\InfluxData\influxdb"
.\influx.exe -host 127.0.0.1

📊 Installing Grafana

Grafana is a powerful visualization platform for time-series data such as InfluxDB metrics.

💡 This project uses Grafana v10+ and InfluxQL as the query language.

Official downloads:
🔗 https://grafana.com/grafana/download

🧩 Windows Installation

  1. Download the Windows installer (grafana-enterprise-<version>.windows-amd64.msi)
    👉 Grafana Download for Windows

  2. Run the installer (accept defaults).
    Grafana will be installed as a Windows Service and starts automatically.

  3. Verify the service is running:
    • Press Windows + R, type services.msc, press Enter.
    • Locate Grafana (or Grafana Enterprise).
    • If not running → right-click → Start.

    Or, from PowerShell (Admin): ```powershell net start grafana

  4. Open Grafana in your browser:
    http://localhost:3000

    Default login:

    Username: admin

    Password: admin

🔧 Step 1 — ESP32 MicroPython Code

Flash and run this code on your ESP32 (e.g., using Thonny):

import network, time, random
from umqtt.simple import MQTTClient

SSID = "TP-LINK_56C612"
PASSWORD = "06941314"

BROKER = "test.mosquitto.org"
PORT = 1883
CLIENT_ID = b"esp32_random_1"
TOPIC = b"/aupp/esp32/random"
KEEPALIVE = 30

def wifi_connect():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    if not wlan.isconnected():
        print("Connecting to WiFi...")
        wlan.connect(SSID, PASSWORD)
        t0 = time.ticks_ms()
        while not wlan.isconnected():
            if time.ticks_diff(time.ticks_ms(), t0) > 20000:
                raise RuntimeError("Wi-Fi connect timeout")
            time.sleep(0.3)
    print("WiFi OK:", wlan.ifconfig())
    return wlan

def make_client():
    return MQTTClient(client_id=CLIENT_ID, server=BROKER, port=PORT, keepalive=KEEPALIVE)

def connect_mqtt(c):
    time.sleep(0.5)
    c.connect()
    print("MQTT connected")

def main():
    wifi_connect()
    client = make_client()
    while True:
        try:
            connect_mqtt(client)
            while True:
                value = random.randint(0, 100)
                msg = str(value)
                client.publish(TOPIC, msg)
                print("Sent:", msg)
                time.sleep(5)
        except OSError as e:
            print("MQTT error:", e)
            try:
                client.close()
            except:
                pass
            print("Retrying MQTT in 3s...")
            time.sleep(3)

main()

This will generate the topic of: /aupp/esp32/random

🧩 Step 2 — Node-RED Setup

  1. Go to powershell and type:
      node-red

    After that you will see the server is running. So, you need hold the CTRL button and click on the server as shown in the image below

Nodered

  1. Then in the Node Red, add the mqttin and the debug in order to verify the data in the node red

mqtt_node

  1. Click on the mqtt and change the parameter as shown in the image below

config

  1. Click deply and check the debug you will see the random value on the right of the image

data

🗄️ Step 3 — InfluxDB Setup

  1. Start InfluxDB:
    cd "C:\Program Files\InfluxData\influxdb"
.\influxd.exe
  2. Open a new PowerShell window:
    cd "C:\Program Files\InfluxData\influxdb"
.\influx.exe -host 127.0.0.1

  3. In the Node Red, install the influxDB

    -> Open Node-RED → ☰ Menu → Manage palette → Install

    -> Search: node-red-contrib-influxdb

    -> Click Install.

    You’ll get two nodes in the left palette:

    InfluxDB out (write to Influx)

    InfluxDB in (query Influx)

  4. After That, config the node-red with influxDB,

node-inf

  • In the Function block add the code below
    msg.measurement = "random";   
msg.payload = { value: Number(msg.payload) };
return msg;

    node-inf

  • In the InfluxDB out you need to add the measurement and the data as shown in the image below

node-inf

node-inf

  • Then click deploy
  1. In the influxDB powershell, you need to create a database for Node-RED
    CREATE DATABASE aupp_lab;
SHOW DATABASES;
USE aupp_lab;

    – Then you do

    SELECT * FROM random ORDER BY time DESC LIMIT 5;

    You will see the data which store in the influxDB as shown in the image below

    node-inf

Launch Grafana

  1. Open Grafana in your browser
    http://localhost:3000

    Default Credentials:

    • Username: admin
    • Password: admin

    Grafana will prompt you to set a new password on first login.

  2. Add InfluxDB as a Data Source

    • On the left sidebar, click ⚙️ (Settings) → Data Sources

    • Click Add data source

    • Select InfluxDB

    • Configure the connection:

  3. Configure InfluxDB Connection

    SettingValue
    Query LanguageInfluxQL
    URLhttp://127.0.0.1:8086
    Databaseaupp_lab
    User / Password(blank unless you configured authentication)
    HTTP MethodGET
    Version1.8+
  4. Create a Dashboard

This step will guide you through creating a real-time dashboard in Grafana to visualize the ESP32 data stored in InfluxDB.

  • In Grafana’s left sidebar, click the “+” (Create) icon

  • Select Dashboard → Add new panel

  • Choose Your Data Source

    • Under Query, select your InfluxDB data source (e.g., InfluxDB - aupp_lab)

    • This connects Grafana to the database where your Node-RED flow is saving data

  1. Then you just need to change the topic to random, you will see the data is updating everytime the esp32 sending the random value

    grafana-inf