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Build an Instrumentation Amplifier with Picoamp-Level Input Bias Current

Build an Instrumentation Amplifier with Picoamp-Level Input Bias Current

Discover how the LT1079 quad op-amp minimizes sensor loading in battery-powered designs. Active cancellation and an onboard bridge network ensure maximum precision for resistive sensors.


Arduino-Compatible RS485 Linear Hall Sensor Board for Magnetic Field Sensing

Arduino-Compatible RS485 Linear Hall Sensor Board for Magnetic Field Sensing

This project brief describes how to build and use an Arduino-compatible board that reads a linear Hall-effect sensor and reports the measurement over an RS485 bus.


A Precision Multi-Sensor Data Acquisition Module

A Precision Multi-Sensor Data Acquisition Module

Build a low-noise, 32-bit delta-sigma ADC board designed around the ADS1262. This 10-channel design features integrated signal conditioning for RTDs, thermocouples, and strain gauges.


An Ultra-Low-Noise Pre-Amp For Audio Applications

An Ultra-Low-Noise Pre-Amp For Audio Applications

Build an ultra-low-noise preamplifier with a JFE150 JFET and OPA202 op-amp, perfect for high-impedance sensors, hydrophones, guitar pickups, microphones, and turntables.


A Four-Channel RS-422 Differential Line Receiver Module

A Four-Channel RS-422 Differential Line Receiver Module

This project brief describes how to build and use a four-channel differential line receiver module for balanced RS-422 and RS-485 data links.


A Four-Channel RS-422 Differential Line Driver Module

A Four-Channel RS-422 Differential Line Driver Module

This project brief describes how to implement a four-channel differential line driver module for reliable long-distance data transmission over balanced twisted-pair lines.


A 7 to 60 V Input Buck Converter: A Wide-Range DC-DC Step-Down Module

A 7 to 60 V Input Buck Converter: A Wide-Range DC-DC Step-Down Module

This project brief describes how to build a wide-range DC-DC buck converter capable of delivering a regulated 5.0 or 3.3 V output from input voltages ranging from 7 to 60 V.


The Voice Echo: An Arduino Audio Project

The Voice Echo: An Arduino Audio Project

This project brief explains how to construct a PCB-based audio-processing platform with an ATmega328 microcontroller. A link to Arduino code for creating an audio echo is also provided.


The Kilo Lamp: An Interactive Lamp Controller

The Kilo Lamp: An Interactive Lamp Controller

This project brief provides the instructions for building a weight-sensitive LED lamp with an Arduino Uno and a handful of commercially available parts.


Using the Arduino Uno Q to Build a DDS Sine Wave Generator

Using the Arduino Uno Q to Build a DDS Sine Wave Generator

In this project, we'll construct and test a microcontroller-based system that digitally generates analog signals.


Projects Apr 19, 2026 by Don Wilcher
Building a Push-Pull Level Shifter to Connect an MCU and a Low-Voltage Display

Building a Push-Pull Level Shifter to Connect an MCU and a Low-Voltage Display

In this project, we'll build and demonstrate a discrete analog solution to the incompatible logic levels of an Arduino Uno and an Elecrow e-paper HMI display.


Projects Nov 23, 2025 by Don Wilcher
Hands-ON With AT Commands: The LoRaWAN Trainer

Hands-ON With AT Commands: The LoRaWAN Trainer

We use a Raspberry Pi and free software to build a test platform for IoT systems.


Projects Mar 02, 2025 by Don Wilcher
Programming Your Standalone Hardware Soundboard

Programming Your Standalone Hardware Soundboard

In Part 2 of this two-part series, we turn our hardware assembly into a functioning soundboard by adding the necessary code in Arduino IDE and uploading soundbites.


Craft Your Own Hardware Soundboard Using an Arduino Microcontroller

Craft Your Own Hardware Soundboard Using an Arduino Microcontroller

Learn how to turn an ATmega328 microcontroller and an assortment of readily available parts into a dedicated hardware soundboard.


The BBC Micro:bit Adjustable Brightness Alarm: A Radio Shack Remix

The BBC Micro:bit Adjustable Brightness Alarm: A Radio Shack Remix

In this project article, we’ll create a programmable device that alerts users to changes in ambient light levels. Along the way, we’ll learn about astable multivibrators and the Darlington pair.


Projects Nov 20, 2024 by Don Wilcher
Building a Resistor Color Code Calculator and Ohmmeter Using Arduino

Building a Resistor Color Code Calculator and Ohmmeter Using Arduino

For this project, I built a handheld resistor color code calculator and ohmmeter using the ATmega328 microcontroller and a 1.8-inch color LCD display.


A Cortex-M Microcontroller-Enabled Electronic Timer: A Radio Shack Remix

A Cortex-M Microcontroller-Enabled Electronic Timer: A Radio Shack Remix

In this Radio Shack Classic Circuits Remix, we add modern microcontroller functionality to the vintage Electronic Timer project for the Science Fair 65-in-1 kit.


Projects Sep 15, 2024 by Don Wilcher
From VHDL Code to Real Hardware: Designing a Finite-State Machine

From VHDL Code to Real Hardware: Designing a Finite-State Machine

Learn how to implement finite-state machines in VHDL by creating a 4-bit binary counter. After compiling, it will run on an Altera CPLD development board connected to a custom PCB with input switches and an LED display.


The Wireless Alphabet Flasher: A Radio Shack Classics Circuit Remix

The Wireless Alphabet Flasher: A Radio Shack Classics Circuit Remix

In this project, we mix the old and the new by integrating present-day BLE technology with a vintage Science Fair computer kit.


Projects Jul 21, 2024 by Don Wilcher
Shake It Off! A Digital Drawing Pad Inspired by the Iconic Etch A Sketch

Shake It Off! A Digital Drawing Pad Inspired by the Iconic Etch A Sketch

In this project, which uses the Arduino IDE, we create and demonstrate a digital drawing pad using an ESP32-based e-paper display dev board, rotary encoders for drawing control, and an accelerometer for shake detection to initiate an erase.