Simple, high-quality condenser microphone DIY for under $100

Schematic PCB

A low-profile version of full-featured software radio based on Raspberry Pi Pico (fully open source + detailed explanation)

With just a Raspberry Pi Pico, an analog switch and an op amp, you can build a powerful SDR receiver covering the LW, MW and SW bands. Capable of receiving signals from halfway around the world.

Schematic PCB

HDMI to MIPI module, mobile phone screen into display (produced by Zhihuijun)

The quality of mobile phone screens is very high and the price is low. It is almost impossible to find mini displays made of mobile phone screens on the market, so this project is to solve this demand.

Schematic PCB

A tiny FIDO2 security key for two-factor authentication and passwordless login

Somu is a small FIDO2 security key that you can use with your Google, Twitter, and GitHub accounts for two-factor authentication, or with your Microsoft account for passwordless login.

Schematic PCB

Make a USB-C power supply (understand the principles of USB-PD in depth, including schematics and English design instructions, etc.)

A simple power supply design based on USB-PD, USB-PD allows to provide voltage up to 20V (current up to 5A), the author shared his design details, you can have an in-depth understanding of the working principle of USB-PD.

Schematic PCB

MCU-based face recognition solution

The MCU-based solution for Face Recognition is a turnkey hardware and single source software solution for adding machine vision to products using the i.MX RT line of crossover processors.

Schematic PCB

Zhihuijun's new work: Hanwen smart keyboard with FOC force feedback knob, multi-function, modular mechanical keyboard (schematic, firmware, etc.)

The keyboard uses a modular design. The multi-functional scene interaction module on the left can be replaced with various custom components. By default, a Dynamic component with an e-ink screen and FOC force feedback knob is used; the keyboard body uses a shift register method to implement the key scanning circuit; The module and keyboard body can be used alone, or they can communicate and call each other through the serial port protocol.

Schematic PCB

200 W Game Console AC-DC Adapter GreenPoint® Reference Design

OM13515: I²C-bus RTC Demonstration Board

I²C bus RTC demo board

SANTA CRUZ (MAXREFDES23#): IO-LINK light sensor

Maxim's Santa Cruz (MAXREFDES23#) reference design is the world's smallest IO-Link® light sensor compliant with IEC 61131-9. The Santa Cruz has six different types of sensors: ambient light (clear), red, green, blue, infrared, and is also a temperature sensor. The entire design fits onto a 6.5mm x 25mm printed circuit board (PCB).

Schematic PCB

Small UAV based on Espressif ESP32-S2/ESP32

ESP-Drone can be connected and controlled through Wi-Fi network using mobile APP or game controller. Currently, it supports multiple modes such as self-stabilizing flight, fixed-altitude flight, and fixed-point flight. This solution has a simple hardware structure, clear code structure, supports function expansion, and can be used in STEAM education and other fields.

Schematic PCB

Watchy - ESP32 ink screen watch with open source software and hardware

​Watchy is a completely open source and customizable e-ink screen watch. It uses ESP32-PICO-D4 as the core, has WiFi and Bluetooth LE connectivity, and is compatible with Arduino, MicroPython and ESP-IDF. The 200x200 pixel resolution e-paper display is clearly visible in bright sunlight and has ultra-low power consumption.

Schematic PCB

MCU-based local voice control solution

The i.MX RT with Built-in MCU-based solution for voice service is a turnkey hardware and single source software solution for adding voice control.

Schematic PCB

Novena: an open source computer based on Freescale and Xilinx FPGA, designed for use as a desktop, laptop or standalone board

Novena is a 1.2GHz, Freescale quad-core ARM architecture computer tightly coupled with Xilinx FPGA. It is designed for users who care about free software and open source, and/or want to modify and extend their hardware: all documentation for the PCB is open and freely downloadable, the entire operating system can be built from source, and it Comes with a variety of features that facilitate rapid prototyping.

Schematic PCB

MAXREFDES44#: Safety-certified design with 1-WIRE ECDSA and XILINX ZYNQ SOC

The MAXREFDES44# subsystem provides a 1-Wire-based reference design for securing a Xilinx system-on-chip (SoC) to protect IP and prevent attached peripheral counterfeiting. The system implements a Public/Private Key 1-Wire ECDSA challenge-response between the SoC and a DS28E35 secure authenticator with on board memory. Boards for purchase, hardware, and firmware design files provide complete system information for rapid prototyping and development.

Schematic PCB

NXH3670ADK development kit

NXH3670ADK development kit

Open Source Electromyography EMG Project

In the open source electromyography project shared here, the author used this product to create a computer game control effect.

Schematic PCB

Open source headphone design based on RP2040 and PCM3060

All files are open source, including software, hardware and 3D printing shells, and how to make and assemble them are described in detail, especially the EQ equalization filter test and frequency response test are explained in detail. The main control uses RP2040 + TI 24-bit asynchronous stereo audio codec PCM3060 with 96/192kHz sampling rate.

Schematic PCB

QN9090DK: Development platform for QN9090/30(T) wireless MCU

Highly Scalable QN Wireless MCU Application Development Platform This development kit is enabled by the QN9090T which supports Bluetooth 5 and NFC.

Schematic PCB

255 W, 80PLUS® Silver Certified ATX Power Supply GreenPoint® Reference Design