Wi‑Fi Builds, Smart Sensors, and Unusual Robots
Build practical connected projects this week: Wi‑Fi fan and relay controllers, ESP32 robot cars, air-quality monitors, solar-powered sensors, and local Bluetooth room mapping.…
3D Printing
What Happened When Resin Printing Got Another Test
Six years after shelving SLA printing, the author tests a new resin printer against 2020 expectations. The results include good-looking parts, failed jobs, setup headaches, and software friction. Fluidd’s open browser workflow makes a useful contrast with slicer APIs, cloud services, authentication demands, and vendor-controlled access.
Read the build on hackaday.com: What Happened When Resin Printing Got Another TestArduino
Build a Wi-Fi Four-Fan Controller
Four fans, one Wi‑Fi-connected board, and open files make this more than an Arduino sketch. The repository covers firmware, electronics documentation, and a printable case, while the microcontroller turns network commands into separate PWM outputs. Check fan ratings and match every file to its hardware revision before building.
Read the build on github.com: Build a Wi-Fi Four-Fan ControllerDIY Electronics
Build a Raspberry Pi Handheld Console
A Raspberry Pi, RetroPie, custom controls, and a 3D-printed case become a portable game console in this detailed build. The guide covers setup, GPIO wiring, screen mounting, battery power, assembly, and testing, while honestly describing the soldering, programming, fitting, and troubleshooting skills the project demands.
Read the build on leandrolinares.com: Build a Raspberry Pi Handheld ConsoleA Touchless Dustbin for Under ₹800
An ordinary dustbin becomes hands-free with an Arduino, ultrasonic distance sensor, and servo-powered lid. The article presents the build as a low-cost beginner project, but the supplied excerpt omits the exact board, component prices, wiring, pin numbers, code settings, power source, and mounting details needed to reproduce it reliably.
Read the build on robocraze.com: A Touchless Dustbin for Under ₹800A Compact Four-Axis ESP32 Motion Board
This early board design packs an ESP32-WROOM, four TMC2209 stepper drivers, storage, communications, cooling, and an auxiliary MOSFET output onto one PCB. It is aimed at custom CNC and motion systems, but the project has not yet established firmware behavior, electrical limits, testing results, or machine performance.
Read the build on hackaday.io: A Compact Four-Axis ESP32 Motion BoardA 40-Year-Old DIY MOSFET Power Amplifier That Still Works
Built from a 1986 Elektor design, this MOSFET amplifier drove discos and beach sound systems for years. Its surviving test unit still worked after decades in a damp basement, offering useful lessons about power supplies, field testing, construction records, and the limits of old performance claims.
Read the build on hackaday.io: A 40-Year-Old DIY MOSFET Power Amplifier That Still WorksESP32
Build a Wi-Fi-Controlled ESP32 Robot Car
Two wireless commands and a motor driver turn an ESP32-C3 into a small rover. This build covers the 2WD chassis, L298N driver, battery wiring, control pins, Wi-Fi firmware, and phone or browser driving. It also shows why shared ground, suitable voltage, and careful motor testing matter.
Read the build on robocraze.com: Build a Wi-Fi-Controlled ESP32 Robot CarESP32 PM Monitor: Display, Cloud Logs, WhatsApp Alerts
Particulate pollution is hard to judge by sight, but this ESP32 build makes it measurable and useful. An SPS30 reports several particle sizes, a TFT shows live values, CircuitDigest Cloud stores readings, and threshold-based firmware sends WhatsApp warnings when the surrounding air may be unsafe.
Read the build on circuitdigest.com: ESP32 PM Monitor: Display, Cloud Logs, WhatsApp AlertsBuild an ESP32 Web Server for Relay Control
An ESP32 can host a simple Wi-Fi control page for switching a relay and a connected load. This practical build explains relay contacts, module choices, wiring, GPIO control, and working web-server code, while keeping the important boundary clear: low-voltage testing is suitable for makers, but mains wiring needs qualified help.
Read the build on randomnerdtutorials.com: Build an ESP32 Web Server for Relay ControlIoT
Solar-Power ESP32 with 18650 Monitoring
Nighttime is the hard part for a Wi-Fi sensor running outdoors. This design stores daytime energy in one 18650 cell, regulates it for an ESP32 or ESP8266, and reports battery voltage through an ADC. Deep sleep helps balance changing sunlight, wireless use, charging limits, and overnight power needs.
Read the build on randomnerdtutorials.com: Solar-Power ESP32 with 18650 MonitoringBuild a Local BLE Room Map for Home Assistant
Room-level Bluetooth tracking makes presence sensors more useful: PadSpan HA combines existing scanners, floor plans, room polygons, and calibration to show where devices are inside a home. It runs locally, updates about every five seconds, and provides maps and diagnostics while leaving accuracy dependent on radio conditions.
Read the build on github.com: Build a Local BLE Room Map for Home AssistantRobotics
A Robot Arm That Serves Badminton Shuttlecocks
Badminton practice usually needs a feeder, but this machine puts that job on a compact Denso VS050 industrial arm. A pneumatic gripper takes shuttlecocks from a hopper, then twin spinning discs launch them. CAD, AVR control, 3D-printed parts, silicone, and court testing make the build especially instructive.
Read the build on hackaday.com: A Robot Arm That Serves Badminton ShuttlecocksPAR Trades Display Speed for Mechanical Simplicity
A 37-by-18 flip-disc display takes a plotter’s approach: one moving tool head visits each pixel instead of giving every disc its own actuator. Color sensing and LIDAR guide each push, making PAR slow but mechanically tidy, while a browser interface lets users draw or upload fresh images.
Read the build on hackaday.com: PAR Trades Display Speed for Mechanical Simplicity