SolderHub Editorial
Articles &
Guides
In-depth tutorials, component deep-dives, and hardware engineering insights — written for builders.
Page 5
ESP32 WiFiManager: Configure WiFi Without Hardcoding SSID & Password
Stop hardcoding WiFi credentials. Use the WiFiManager library to give your ESP32 a captive configuration portal: first-boot setup from a phone, saved credentials, custom MQTT fields, a reset button, timeouts and fixes for the common pitfalls.
Live DHT11 and BMP280 Dashboard with ESP32 and MQTT
Send DHT11 temperature/humidity and BMP280 temperature/pressure from an ESP32 to Node-RED over MQTT, validate JSON telemetry, and build a Dashboard 2.0 view with sensible ranges and clear stale-data status.
ESP32 WiFi Not Connecting? Fix Connection Failed, Disconnects & Timeouts
A step-by-step ESP32 WiFi troubleshooting guide: decode status and disconnect reason codes, fix wrong password, 5 GHz, WPA3, weak signal and power problems, and add a robust reconnect and watchdog strategy that keeps your device online.
Read Arduino Uno or Nano Sensors over Serial in Node-RED
Read sensor measurements from Arduino Uno or Nano over USB serial into Node-RED. Use newline-delimited records, configure the serial node correctly, parse JSON, validate data and troubleshoot port and baud-rate problems.
STM32 Low-Power Modes: Sleep, Stop, and Standby Explained (With Working Code)
A practical guide to STM32's three-tier low-power system — Sleep, Stop, and Standby — with working STM32duino code, measured current draw on a Blue Pill, and a battery-powered project example.
Raspberry Pi Pico W Pinout: Every GPIO, ADC, and Wireless Pin Explained
Complete Raspberry Pi Pico W pinout reference: 26 usable GPIOs, the wireless-chip pin sharing on GP23/24/25/29, ADC, PWM, I2C, SPI, UART, and why the onboard LED isn't on GPIO 25 anymore.
ESP32 GPIO Input vs Output: Beginner Guide to LEDs, Buttons & Pull-Ups
Learn ESP32 digital input and output from scratch: blink an LED, read a button with INPUT_PULLUP, understand pull-up and pull-down resistors, debounce properly, calculate LED resistors and avoid the pin mistakes that break beginner projects.
STM32 Blue Pill Pinout: Every GPIO, ADC, and Alternate Function Explained
A complete STM32F103C8T6 Blue Pill pinout reference: every GPIO port, ADC channel, timer, and communication bus mapped, plus the 5V-tolerance and clone-board considerations that affect wiring decisions.
MQTT Explained: Broker, Topics, QoS, Retained Messages and Last Will
Understand MQTT without writing code. Learn how brokers route publish/subscribe messages, how topic hierarchies and wildcards work, what QoS guarantees, when to retain state and how Last Will supports device availability.
STM32 Black Pill Pinout: Every GPIO, ADC, and Peripheral Explained
Complete STM32 Black Pill (STM32F411CEU6) pinout reference: GPIO ports, 12-bit ADC, timers/PWM, USART, SPI, I2C, and the 3.3V-only pins to watch out for.
Raspberry Pi Zero Pinout: GPIO, Power, and Zero-Specific Ports Explained
Complete Raspberry Pi Zero pinout reference: a full pin-by-pin 40-pin GPIO table, physical vs BCM numbering, I2C/SPI/UART, and the Zero-specific port quirks (mini-HDMI, micro-USB OTG, camera cable).
ESP32 I2C Pins: SDA, SCL & Using Multiple I2C Devices
Everything about ESP32 I2C: default SDA and SCL pins, how to change them, scanning for device addresses, connecting an OLED and BME280 on one bus, fixing address conflicts, using the second I2C bus, pull-up resistors and common errors.