Blog

Simple DCR (Direct Conversion Receiver) – Part 2: Common Emitter Amplifier

shabaz

Table of Contents Introduction Circuit Diagram Dealing with Inputs and Outputs Power Supply Problem! Applying a Signal Frequency Response Loading the Amplifier Testing Both Stages Together Summary For all blog posts in this series, click here, o...
- 24 Mar 2026
A 4-zone universal transmitter node for open-drain sensors (Proof of Concept)

BigG

Introduction Traditional home security systems have long relied on a centralized architecture. All of the signal processing and control logic lives in a single, often bulky, cabinet. The user interface is usually just a simple keypad used for arming ...
- 19 Mar 2026
Simple DCR: Assembling a 7 MHz (40m) Direct Conversion Radio Receiver – Part 1

shabaz

Table of Contents Introduction How Does It Work? How to Build It? Circuit Diagram What Has Been Constructed So Far? Audio Amplifier Testing the Amplifier’s Third Stage Summary For all blog posts in this series, click here, or type simple_d...
- 12 Mar 2026
EoRa-S3-900TB with FreeRTOS — LoRa Camera Control System --Avg 174 µA

AB9NQ-William

A long-range wireless camera battery control system built on the EoRa-S3-900TB development board (ESP32-S3 + SX1262 LoRa). A FreeRTOS-based Transmitter (TX) sends commands over LoRa to a deep-sleep Receiver (RX) that controls camera power v...
- 28 Feb 2026
Easy Xmas Gift: Simple LED Name Signs or Night-Lights

shabaz

I had a small request from a friend to produce a night-light that spelled out his kids' names. This turned out to be a very easy project. I obtained quarter-circle wood dowel with a 45-degree cut on the inside, instead of a sharp 90 degree corne...
- 8 Dec 2025
MiniThermaDrive: Fun with 3D Printer Heating Elements - Part 1

shabaz

Table of Contents Introduction What can it be used for? High-Level Design Driver Board Summary Introduction Ever wanted to heat something to a precise temperature? I have, but I initially didn’t know how to go about it. 3D printer spares a...
- 5 Nov 2025
LoRa Standalone Sensor Network ~45 µA Node with radio.sleep and deep sleep

AB9NQ-William

"LoRa BME280 Sensor Network" a collaboration between Anthropic's Claude and William Lucid. Project requires two, "Ebyte" EoRa-S3-900TB Development Boards; one for Gateway and one for Node. One 74HC04 for each node to reroute the Lora DIO1 signal to ...
- 9 Oct 2025
CH340: Building Yet Another USB-C to UART Adapter Board

shabaz

Table of Contents Introduction Features Circuit Diagram Building It Using It Summary Introduction USB-to-UART adapters are extremely useful when connecting devices, as UART is a widely standard protocol available on many microcontrollers and per...
- 27 Aug 2025
Building a VK5JST Antenna Analyzer for HF, VHF and UHF

shabaz

Table of Contents Introduction Obtain a Kit of Parts Building an Enclosure Flex PCB Construction Panel Meter End Panel RF Connector Assembly Main Board Parts Soldering Joining the End Panel and Main Board Attaching the End Panel/Main Board Assembly...
- 8 Jun 2025
A Three-Way Prototyping Board for Awkward Through-Hole Components

shabaz

Table of Contents Introduction What Problems Does it Solve? Working with Dual-in-Line (DIL)Headers Working With Pi Pico and other Wide DIP Devices Easy Desoldering Easy Grounding Large Screw Terminals and Connectors Support Summary Introd...
- 14 Mar 2025
Half-Hour Project: Building a Simple Audio Amplifier

shabaz

Table of Contents Introduction How Does it Work? Building It Using It Summary Introduction A while back I built a little audio amplifier based on a circuit found in an old book. The amplifier performed reasonably OK (by that I mean adequat...
- 5 Mar 2025
KiCad 8: Working with Circuit Simulations!

shabaz

Table of Contents Introduction Create the Schematic Adding SPICE models Adding Simulation Voltages Running a Simulation Plotting Frequency Response Simulating Parts of a Circuit (Excluding some Components) Summary Introduction The recent release...
- 5 Sep 2024
Bridgetek EVE Series - Touch Enabled Graphical User Interfaces

BRT-Marketing

Bridgetek’s products include the EVE family of display controllers which make it easy to add attractive and fully featured touch-enabled graphical user interfaces to existing and new product designs. To improve the user experience and functiona...
- 26 Jan 2024
High Voltage Isolated Measurement Board: Initial Prototype

shabaz

Introduction In an earlier blog post Very Low-Cost Pulse-Width Modulation (PWM), and Isolated Analog Measurements a method was discussed to perform isolated analog measurements at a sub-£1/$1 price. It was fine for slow-ch...
- 13 Dec 2023
Very Low-Cost Pulse-Width Modulation (PWM), and Isolated Analog Measurements

shabaz

This is just an ultra-quick blog post about an interesting circuit. I wanted to be able to measure an output up to about 1kV, and so I really desired the measurement to be isolated! I also wanted it to be cheap. This blog post shows the method I won&...
- 24 Nov 2023
Writing Decent Blogs: A Blog Checklist!

shabaz

Table of Contents Introduction: What’s a Blog Checklist? Good Flow, Bad Flow? Value Fun to Read? Is the Content Appropriate? Is the Content Relevant? Use a Table of Contents Write an Introduction Write a Summary Make Use of the Editor To...
- 12 Nov 2023
GitHub for Beginners: Feature Development for Projects

shabaz

This blog post is a joint effort by Jan Cumps and shabaz Table of Contents Introduction IDE Capabilities JetBrains Products Visual Studio Code A Suggested Strategy Fork the Project Repository Cloning your Reposi...
- 11 Aug 2023
Using Buses in Circuits with KiCad 7

shabaz

This topic is a bit fiddly to describe in words, so I hope the video will suffice. This blog won't have much text : ( I feel like a Ronin when I'm not having to type though! : ( https://youtu.be/T5Zy_BWg3Tw
- 29 Jul 2023
Vintage Curvy PCB Traces with KiCad 7

shabaz

Table of Contents Introduction What’s Required? Running the Plugin Fixing Issues Summary Introduction Old-school printed circuit boards (PCBs) often had wavy copper traces! They were done manually by rolling out UV-light-blocking crepe sti...
- 3 Jul 2023
Working with KiCad 7: Importing EAGLE files

shabaz

Table of Contents Introduction Importing the project Enabling Schematic and PCB Updates Resolving PCB Problems Zones (Copper planes) Rule Areas (Keepout regions) Component Footprints Resolving Schematic Problems Text Sizes Drawing Frame ...
- 27 Jun 2023
Problem Solving with KiCad 7 and Python: Getting Data and Moving Components on Circuit Boards

shabaz

Table of Contents Introduction Python Console Getting Footprint Information Python writing Python Trying it Out Holes in a Geometric Pattern Summary Introduction One of the great advantages of KiCad is that it supports a decent language for scri...
- 25 Jun 2023
GitHub for Beginners: Working with PyCharm and other JetBrains IDEs

shabaz

Table of Contents Introduction Cloning a Repository Creating a Branch and Publishing the Branch Editing Code and Committing your Code Creating a Pull Request Merging the Code to the main branch Creating your Next Feature Viewing Branches Graphicall...
- 24 Jun 2023
GitHub for Beginners: Incrementally Adding Features to your Code

shabaz

Table of Contents Introduction What is GitHub and Version Control, and Why is it useful? What Really Happens Installing Software Cloning (Checking out) Code Creating a Branch and Publishing the Branch Editing Code and Committing Code Creating a Pul...
- 23 Jun 2023
Inkplate 2

ralphjy

Back in December of last year I backed a Kickstarter campaign by Soldered Electronics for the Inkplate 2 - a 2.13" e-paper display with an ESP32 microcontroller. I received my unit about a month ago, but have been busy with design challenges and...
- 16 Jun 2023
Oscillator design

strb

I was surfing the net looking for inspiration to build something new to me when I stumbled across Building a Voltage-Controlled Oscillator (VCO) by shabaz . His blog post inspired me quite a lot, but also showed me the amount of work a...
- 8 Jan 2023