SolderHub Editorial
Articles &
Guides
In-depth tutorials, component deep-dives, and hardware engineering insights — written for builders.
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Node-RED Dashboard 2.0: Install Buttons, Switches and Gauges
Install FlowFuse Dashboard (Node-RED Dashboard 2.0), create a responsive page, and connect a button, switch and gauge to real flow messages. Includes package naming, a first working layout, troubleshooting and migration guidance from the deprecated legacy dashboard.
Install Mosquitto on Raspberry Pi 5: Secure MQTT Broker Setup
Install Eclipse Mosquitto on Raspberry Pi 5, start the broker as a service, test publish/subscribe locally, and configure remote LAN access with explicit listeners and password authentication. Explains the Mosquitto 2.0 local-only default and safe next steps for TLS.
MQTT Troubleshooting: Connection Refused, rc=-2 and rc=5
Diagnose MQTT connection failures systematically. Understand broker listener and port problems, PubSubClient rc=-2 and rc=5, authentication, client IDs, topic mismatches and reconnect logs for ESP32, ESP8266, Mosquitto and Node-RED.
ESP32 REST API Tutorial: Build a JSON API for Sensors and Relays
Turn your ESP32 into a REST API server with the built-in WebServer library: JSON GET endpoints for sensor data, POST endpoints to control an LED or relay, API-key protection, CORS, error handling and testing with curl and a browser.
Non-Blocking MQTT Auto-Reconnect on ESP32
Make an ESP32 MQTT client recover from Wi-Fi and broker outages without long delay() calls. Use millis()-based retry scheduling, capped backoff, unique client IDs, resubscription after reconnect and local work that continues while offline.
ESP32 MQTT Temperature Sensor: Send DHT22 Data to Home Assistant
Build an ESP32 temperature and humidity sensor that appears in Home Assistant automatically using MQTT Discovery. Includes DHT22 wiring, complete PubSubClient code with availability and reconnect, dashboard setup, an alert automation and troubleshooting.
ESP32 + Home Assistant WiFi Smart Switch: Relay, Button & MQTT Discovery
Build a WiFi smart switch with an ESP32 and a relay that appears in Home Assistant automatically through MQTT Discovery. Includes a physical button, power-loss state restore, safe relay wiring, full code, an automation and a safety section on mains voltage.
Control an ESP32 LED from the Blynk App: Virtual Pins vs GPIO
Build a simple Blynk 2.0 LED controller for ESP32. Configure a V0 datastream and dashboard switch, upload firmware using the Blynk library, map the virtual pin to a physical GPIO and troubleshoot connection and state-sync problems.
ESP32 Home Assistant Without MQTT: ESPHome, REST & Webhooks Compared
Four ways to connect an ESP32 to Home Assistant without MQTT: ESPHome native API (easiest), REST sensors and switches, webhooks and the Home Assistant REST API. Working YAML and code for each, plus a decision guide and troubleshooting.
MQTT Complete Guide for ESP32, ESP8266 and Raspberry Pi
Master MQTT for IoT with a practical guide to brokers, topics, QoS, retained messages, Last Will, Mosquitto, ESP32/ESP8266 firmware and Raspberry Pi integrations. Start with command-line tests and build toward secure, resilient systems.
ESP32 WebSocket Tutorial: Real-Time Sensor Data Dashboard (Arduino IDE)
Build a real-time ESP32 WebSocket server: push live sensor readings to a browser graph, control an LED from the page, handle reconnects and heartbeats, and learn when WebSockets beat HTTP polling and MQTT.
Your First Node-RED Flow: Inject, Function and Debug
Build your first working Node-RED flow with Inject, Function and Debug nodes. Learn how messages and msg.payload move through a flow, deploy changes, inspect output and troubleshoot common beginner mistakes.