A tiny knock becomes a surprisingly expressive Halloween reaction. This child friendly box uses an electret microphone, a one transistor amplifier, an Arduino, and a servo to sense sound and move a monster. Its schematic and construction notes also teach biasing, AC coupling, threshold detection, and servo control through one playful build.
Read the build on build-electronic-circuits.com: Build a Knock Activated Monster Box
OnePage turns an ESP32 C61 board into the center of a complete DIY e reader project. Its repository connects electronics, firmware, enclosure files, a board SDK, and browser tools, giving makers a practical way to inspect, source, fabricate, assemble, and adapt a wireless handheld reading device.
Read the build on github.com: OnePage: Build an ESP32 C61 E Reader
A custom PCB turns the PYNQ-Z2 into an open measurement platform with a dual channel, 16 bit oscilloscope, logic analyzer connection, and arbitrary waveform generator. FPGA logic handles acquisition and processing, while ngscopeclient provides a desktop view. The repository also documents planned AI integration, though implementation details remain limited.
Read the build on pcbway.com: Building a PYNQ-Z2 Mixed-Signal Oscilloscope
RP1 treats a humanoid robot as a reproducible system, not a sealed demonstration. Its repository connects structure, joints, electronics, firmware, control, and learning tools, while publishing CAD, schematics, PCB layouts, Gerbers, BOM data, and assembly notes for builders with serious fabrication and robotics experience.
Read the build on github.com: RP1 Opens the Full Humanoid Robot Stack
Sunlight can move a lightweight homemade car when a small photovoltaic panel feeds a DC motor directly. This quick build uses inexpensive parts, then becomes a useful test platform for light levels, panel angles, wheel sizes, friction, and gearing. Record speed, compare results, and present the evidence with simple graphs.
Read the build on spheralsolar.com: Build a Low Cost Solar Car That Moves
Linorobot2 puts the electronics and firmware for a ROS 2 mobile robot on familiar ESP32s and Raspberry Pi Picos. It links motor control and odometry to ROS 2, with USB or Wi-Fi communication, OTA updates, and network diagnostics. The repository still expects its wiki for wiring and bring-up details.
Read the build on github.com: Build a ROS 2 Rover with ESP32 or Pico