The short-wave technique has a very particular appeal: It can easily bridge long distances. By reflecting short-wave signals off the conductive layers of the ionosphere, they can be received in places beyond the horizon and therefore can reach anywhere on earth. Although technology is striving for ever higher frequencies, and radio is usually listened to on FM, DAB+, satellite or the Internet, modern means of transmission require extensive infrastructure and are extremely vulnerable. In the event of a global power outage, there is nothing more important than the short-wave. Amateur radio is not only a hobby, it’s also an emergency radio system!
Elektor’s SDR-Shield is a versatile shortwave receiver up to 30 MHz. Using an Arduino and the appropriate software, radio stations, morse signals, SSB stations, and digital signals can be received.
In this book, successful author and enthusiastic radio amateur, Burkhard Kainka describes the modern practice of software defined radio using the Elektor SDR Shield. He not only imparts a theoretical background but also explains numerous open source software tools.
Make your project dreams come true: an odometer for the hamster wheel, a fully automatic control of your ant farm with web interface, or the Sandwich-O-Mat – a machine that toasts and grills sandwiches of your choice.
With the Arduino and the DIY or Maker movement, not only did entry into microcontroller programming become child's play, but a second development also took place: Resourceful developers brought small boards – so-called shields or modules – to the market, which greatly simplified the use of additional hardware. The small modules contain all the important electronic parts to be connected to the microcontroller with a few plug-in cables, eliminating the need for a fiddly and time-consuming assembly on the plug-in board. In addition, it is also possible to handle tiny components that do not have any connecting legs (so-called SMDs).
Projects Discussed
Arduino seeks connection
BMP and introduction to libraries, I²C
Learn I/O basics with the multi-purpose shield
I²C LCD adapter and DOT matrix displays
LCD keypad shield
Level converter
W5100: Internet connection
I/O expansion shield
Relays and solid-state relays
The multi-function shield: A universal control unit
Connecting an SD card reader via SPI
Keys and 7-segment displays
16-bit ADC
MCP4725 DAC
16-way PWM servo driver
MP3 player
GPS data logger using an SD card
Touch sensor
Joystick
SHT31: Temperature and humidity
VEML6070 UV-A sensor
VL53L0X time-of-flight
Ultrasonic distance meter
MAX7219-based LED DOT matrix display
DS3231 RTC
Port expander MCP23017
433 MHz radio
MPU-650 gyroscope
ADXL345 accelerometer
WS2812 RGB LEDs
Power supply
MQ-xx gas sensors
CO2 gas sensor
ACS712 current sensor
INA219 current sensor
L298 motor driver
MFRC522 RFID
28BYJ-48 stepper motor
TMC2209 silent step stick
X9C10x digital potentiometer
ST7735 in a color TFT display
e-Paper display
Bluetooth
Geiger counter
SIM800L GSM module
I²C multiplexer
Controller Area Network
Praktischer Einstieg mit Arduino, GnuRadio und FPGA
Das Thema „Software Defined Radio“ ist facettenreich: Neben der Schaltungstechnik ist auch eine Einarbeitung in die Programmierung von Hardware und PC wichtig. Ein schrittweises Vorgehen erleichtert Ihnen den Einstieg. Mit dem im Buch vorgestellten modularen „RF Bricks“-Konzept werden Sie zum Architekten Ihrer Signalkette. Auf einem Chassis angeordnet gewährleisten die Module einen soliden und gut abgeschirmten Aufbau, den Sie einfach verändern und mit eigenen Ideen anreichern können.
Der skalierbare Aufbau bildet Ihr Blockschaltbild auch mechanisch ab – die so gewonnene Übersicht kann in der Aus- und Weiterbildung nützlich sein. Ein Arduino in Ihrem Chassis kommuniziert nach einigen Anpassungen mit üblichen SDR-Programmen, z. B. SDRCPP, GQRX und CubicSDR auf einer Linux-Plattform. Damit können Sie Ihren Empfänger direkt per Mausklick abstimmen.
Wenn Sie Blockschaltbilder mögen, ist GnuRadio ein natürlicher Partner der „RF Bricks“. Mit einem selbst programmierten Python-Block gelingt Ihnen in GnuRadio die Fernsteuerung Ihres Empfängers. Im GnuRadio-Universum können Sie Ihre GUI stufenweise ausbauen, behalten dabei aber immer volle Kontrolle über die inneren Abläufe des Programms.
Mit einem FPGA können zeitaufwändige Operationen auch direkt in die Hardware verlagert werden. Sie bauen stufenweise einen Doppelsuperhet auf und entwickeln die Filterkoeffizienten für FIR-Filter mit Scilab. Das in VHDL realisierte Weaver-Schema rundet diesen Empfänger ab, der mit hoher Empfindlichkeit und Dynamik aufwarten kann.
Mit dem gewonnen Überblick und Ihrer neuen Hardware können Sie die einzelnen Aspekte des Themenkomplexes SDR beliebig weiter vertiefen.
Downloads
Software
Practical Guide to Modular RF Design
Build Your Own Software-Defined Radio combines RF circuitry with hardware programming and PC-based signal processing. The e-book presents a modular approach to building a complete SDR system using RF Bricks – from the mechanical framework and RF modules to measurement tools, PC software, and FPGA implementations. Practical explanations guide readers through real signal paths, construction steps, and measurement routines, linking hardware and software into a flexible SDR platform.
Key topics include:
Mechanical setup: RF Brick template, chassis, and 19-inch module carrier
Bridges: USB isolator, I²C level shifter, I²C power switch, and practical examples
Signal-chain design with RF Bricks: antennas, band filters, NanoVNA work, preamplifiers, PLLs, demodulators, direct-conversion chains, multiband options, and narrowband bricks
RF measurement Bricks: single- and dual-tone sources, NPR methods, noise generators, notch filters, broadband amplifiers, and impedance bridges
Useful accessories: ATU-100 tuner, X-Phase QRM eliminator, and firmware notes
PC host software: SoapyAudio adjustments, GQRX, SDR++, and added functionality
GnuRadio elements: control blocks, SSB demodulation, GUI components, messaging, and filter handling
FPGA-based SDR: VHDL, toolchains, ADC/DAC blocks, oversampling, and a complete SSB/CW signal chain
With its modular structure and detailed working examples, this e-book offers a practical path to building and extending modern SDR systems.
Downloads
Software
Over 40 Fully Tested ESP32 Projects Using Arduino IDE and the LVGL Graphics Library
This bundle includes the ESP32 Cheap Yellow Display (CYD) – a compact development board combining a standard ESP32 microcontroller with a 320x240 pixel TFT color display. The board also features multiple connectors for GPIO, serial communication (TX/RX), power, and ground. The built-in display is a major advantage, allowing users to create complex, graphics-based projects without the need for external LCDs or displays.
The accompanying book introduces the CYD board's hardware and on-board connectors in detail. It provides a range of beginner to intermediate-level projects developed using the popular Arduino IDE 2.0. Both basic graphics functions and the powerful LVGL graphics library are covered, with practical projects illustrating each approach.
All included projects have been fully tested and are ready to use. The book provides block diagrams, circuit schematics, complete code listings, and step-by-step explanations. With the LVGL library, readers can create modern, full-color graphical interfaces using widgets such as buttons, labels, sliders, calendars, keyboards, charts, tables, menus, animations, and more.
ESP32 Cheap Yellow Display Board
This development board (also known as "Cheap Yellow Display") is powered by the ESP-WROOM-32, a dual-core MCU with integrated Wi-Fi and Bluetooth capabilities. It operates at a main frequency of up to 240 MHz, with 520 KB SRAM, 448 KBROM, and a 4 MB Flash memory. The board features a 2.8-inch display with a resolution of 240x320 and resistive touch.
Furthermore, the board includes a backlight control circuit, touch control circuit, speaker drive circuit, photosensitive circuit, and RGB-LED control circuit. It also provides a TF card slot, serial interface, DHT11 temperature and humidity sensor interface, and additional IO ports.
The module supports development in Arduino IDE, ESP-IDE, MicroPython, and Mixly.
Applications
Image transmission for Smart Home device
Wireless monitoring
Smart agriculture
QR wireless recognition
Wireless positioning system signal
And other IoT applications
Specifications
Microcontroller
ESP-WROOM-32 (Dual-core MCU with integrated Wi-Fi and Bluetooth)
Frequency
Up to 240 MHz (computing power is up to 600 DMIPS)
SRAM
520 KB
ROM
448 KB
Flash
4 MB
Operating voltage
5 V
Power consumption
approx. 115 mA
Display
2.8-inch color TFT screen (240 x 320)
Touch
Resistive Touch
Driver chip
ILI9341
Dimensions
50 x 86 mm
Weight
50 g
Downloads
GitHub
This bundle contains:
The ESP32 Cheap Yellow Display Book (normal price: €35)
ESP32 Cheap Yellow Display Board (normal price: €25)
1x ESP32 Dev Board with 2.8" Display and acrylic Shell
1x Touch pen
1x Connector cable
1x USB cable
DEAL: Order the HackRF Pro now and get the new e-book "SDR with HackRF One & HackRF Pro" worth €20 for FREE!
HackRF Pro is latest Software Defined Radio (SDR) from Great Scott Gadgets and the powerful successor to the legendary HackRF One. With a frequency range from 100 kHz to 6 GHz, it covers an enormous spectrum for transmitting and receiving radio signals.
Designed as an open-source hardware platform, the HackRF Pro is the ideal tool for analyzing and developing modern wireless technologies. It can be used flexibly as a USB peripheral or programmed for standalone operation.
Specifications
Frequency: 100 kHz to 6 GHz
Adjustable from 0 Hz to 7.1 GHz
Half-duplex transceiver
Up to 20 million samples per second
8-bit quadrature samples (8-bit I and 8-bit Q)
Compatible with GNU Radio, SDR#, and more
Software-configurable RX and TX gain and baseband filter
Software-controlled RF port power (50 mA at 3.3 V)
SMA RF connector
SMA clock input and output for synchronization and triggering
Convenient buttons for programming
Internal pin headers for expansion
High-Speed USB 2.0 with USB-C connector
USB-powered
Open source hardware
Compared to its predecessor, HackRF Pro offers a variety of new features, including:
Wider operating frequency range
Improved RF performance with flatter frequency response
USB-C connector
Built-in TCXO crystal oscillator for superior timing stability
Logic upgrade from a CPLD to a power-efficient FPGA
Elimination of the DC spike
Extended-precision mode with 16-bit samples for low sample rates (typical ENOB: 9-11)
Half-precision mode with 4-bit samples at up to 40 Msps
More RAM and flash memory for custom firmware
Installed shielding around the radio section
Trigger input and output accessible through clock connectors
Cutout in the PCB provides space for future add-ons
Improved power management
Enhanced RF port protection
Facility to hardware-disable transmit mode
Full Compatibility: Thanks to its proven architecture, existing software for the HackRF One can also be used directly with the HackRF Pro. The HackRF Pro offers seamless backward compatibility while significantly increasing performance.
Note: An antenna is not included. We recommend the ANT500 for the best experience.
Included
HackRF Pro SDR with plastic enclosure
NEW e-book: SDR with HackRF One & HackRF Pro (normal price: €20)
Downloads
Documentation
GitHub
Programming with GNU Radio
HackRF is an open-source hardware platform developed by Great Scott Gadgets and serves as a versatile front end for software-defined radio (SDR). With HackRF One and its successor, HackRF Pro, users can develop their own SDR applications, build powerful receivers and transmitters, and tackle demanding RF measurement tasks.
This book provides a practical introduction to the world of SDR. Step by step, the author shows how powerful SDR projects can be implemented with HackRF – from the fundamentals of RF technology to advanced applications using GNU Radio.
In addition to working with SDR Sharp (SDR#), RadioConda, and GNU Radio, the book also covers the fundamentals of modern digital signal processing. Numerous experiments and easy-to-follow practical examples guide readers through topics such as AM, FM, and SSB reception, digital filters, shortwave radio, amateur radio, signal generators, and custom RF projects up to 6 GHz.
Whether you are a maker, radio amateur, electronics enthusiast, or SDR beginner, this book provides solid knowledge, practical applications, and the motivation to creatively explore the possibilities of modern SDR technology.
The Elektor ESP32 Energy Meter is a device designed for real-time energy monitoring and smart home integration. Powered by the ESP32-S3 microcontroller, it offers robust performance with modular and scalable features.
The device uses a 110/230 VAC to 12 VAC step-down transformer for voltage sampling, ensuring galvanic isolation and safety. Its compact PCB layout includes screw-type terminal blocks for secure connections, a Qwiic connector for additional sensors, and a programming header for direct ESP32-S3 configuration. The energy meter is compatible with single-phase and three-phase systems, making it adaptable for various applications.
The energy meter is simple to set up and integrates with Home Assistant, offering real-time monitoring, historical analytics, and automation capabilities. It provides accurate measurements of voltage, current, and power, making it a valuable tool for energy management in homes and businesses.
Features
Comprehensive Energy Monitoring: Get detailed insights into your energy usage for smarter management and cost savings.
Customizable Software: Tailor functionality to your needs by programming and integrating custom sensors.
Smart Home Ready: Compatible with ESPHome, Home Assistant, and MQTT for full Smart Home integration.
Safe & Flexible Design: Operates with a 110/230 VAC to 12 VAC step-down transformer and features a pre-assembled SMD board.
Quick Start: Includes one Current Transformer (CT) sensor and access to free setup resources.
Specifications
Microcontroller
ESP32-S3-WROOM-1-N8R2
Energy Metering IC
ATM90E32AS
Status Indicators
4x LEDs for power consumption indication2x Programmable LEDs for custom status notifications
User Input
2x Push buttons for user control
Display Output
I²C OLED display for real-time power consumption visualization
Input Voltage
12~16 VAC (via a step-down transformer 110/230 VAC to 12 VAC)
Clamp Current Sensor
YHDC SCT013-000 (100 A/50 mA) included
Smart Home Integration
ESPHome, Home Assistant, and MQTT for seamless connectivity
Connectivity
Header for programming, Qwiic for sensor expansion
Applications
Supports single-phase and three-phase energy monitoring systems
Dimensions
79.5 x 79.5 mm
Included
1x Partly assembled board (SMDs are pre-mounted)
2x Screw terminal block connectors (not mounted)
1x YHDC SCT013-000 current transformer
Required
Power transformer not included
Downloads
Datasheet (ESP32-S3-WROOM-1)
Datasheet (ATM90E32AS)
Datasheet (SCT013-000)
Frequently Asked Questions (FAQ)
From Prototype to Finished Product
What started as an innovative project to create a reliable and user-friendly energy meter using the ESP32-S3 microcontroller has evolved into a robust product. Initially developed as an open-source project, the ESP32 Energy Meter aimed to provide precise energy monitoring, smart home integration and more. Through meticulous hardware and firmware development, the energy meter now stands as a compact, versatile solution for energy management.
Complete ESP32 microcontroller learning course featuring a custom-designed MCU expansion board, hands-on projects, and a comprehensive online guide – perfect for learning hardware, programming, and connectivity step by step.
A Practical Introduction to Embedded Systems with the ESP32
This course is designed for readers who are new to embedded systems and looking for a structured, example-driven way to get started. If you’ve explored general-purpose electronics or Arduino-based materials but found them too broad or lacking in practical guidance, this course offers a more focused alternative.
Using the "ESP32 by Example Kit" (EEK) – a compact and affordable set of components featuring LEDs, sensors, an OLED display, and a motion processor – you’ll work with a consistent hardware setup throughout the course. Once assembled, the EEK stays mostly unchanged, allowing you to concentrate on learning and experimentation without constant reconfiguration.
Topics include:
Understanding and programming the ESP32 microcontroller
Writing and deploying code with the Arduino IDE
Exploring cyber-physical systems, culminating in basic drone control
No prior experience with Arduino or embedded development is required. Each section features hands-on examples and mini-projects designed to reinforce key concepts and inspire deeper exploration. By the end of the course, you’ll be able not only to reproduce the book’s examples but also to build on them with your own ideas and applications.
Whether you're interested in embedded programming, interactive systems, or introductory drone control, this course provides a clear and practical path to getting started.
What you'll learn?
Embedded programming with the ESP32 using the Arduino IDE
Real-time sensor input and control via buttons, LEDs, and displays
Gesture-based interaction using the MPU6050 motion sensor
Bluetooth gamepad integration and drone control simulation
Wi-Fi and UDP networking, local web servers, and NTP
MQTT communication with cloud platforms like AWS and Arduino IoT
How to build and deploy full-featured IoT systems
Perfect for
Students and self-learners exploring embedded systems
Makers and IoT enthusiasts looking to improve their hardware skills
Educators and trainers seeking ready-to-teach material
Developers moving beyond Raspberry Pi or Arduino basics
Support when you need it
Access to instructors via Elektor Academy
Helpful community forums and essential documentation
What's inside the Box (Course)?
New 384-page book: "ESP32 by Example" (valued at €45)
Elektor ESP32 by Example Kit (EEK): Microcontroller Extension Board with 6 LEDs and 6 Buttons installed + OLED Display, MPU6050 3-axis Accelerometer and Gyroscope Module (valued at €40)
Adafruit HUZZAH32 – ESP32 Feather MCU Board (valued at €30)
ESP32 Cheap Yellow Display Board (valued at €25)
DHT11 Humidity & Temperature Sensor
Breadboard
Jumper wires
USB-C cable
Access to the full course on the Elektor Academy Pro Learning Platform
Instructional videos
Downloadable Arduino project files for every module
Learning Material (of this Box/Course)
▶ Click here to open
Module 1 – Getting Started with the ESP32 & EEK
Module 2 – Digital Output – LEDs and GPIO
Module 3 – Switches and Input Handling
Module 4 – EEK and PWM
Module 5 – OLED and Display Output
Module 6 – Motion Sensing with the MPU6050
Module 7 – Capstone Project (EEK in Action)
Module 8 – WiFi and Web Control with ESP32
Module 9 – Cloud Concepts using EEK
Module 10 – Hands-on: Arduino IoT Cloud and EEK
Module 11 – BlueTooth and EEK GamePad Integration
Module 12 – Why Drones?
Module 13 – Drone Simulator Concepts
Module 14 – Simple Drone Flight Control
Module 15 – Real-Time Drone Flight Control
Module 16 – Drone Control Mini-Projects
Module 17 – Middleware and Python Scripting
Module 18 – Python Applications for Drone Control
Module 19 – Capstone EEK Control Project and Presentation
About the Author
Dr. Jim Solderitsch is an educator, software architect, systems developer, and cybersecurity researcher with a focus on cyber-physical systems. He currently serves as an Adjunct Professor in Computing Sciences at Villanova University in Pennsylvania.
What is Elektor Academy Pro?
Elektor Academy Pro delivers specialized learning solutions designed for professionals, engineering teams, and technical experts in the electronics and embedded systems industry. It enables individuals and organizations to expand their practical knowledge, enhance their skills, and stay ahead of the curve through high-quality resources and hands-on training tools.
From real-world projects and expert-led courses to in-depth technical insights, Elektor empowers engineers to tackle today’s electronics and embedded systems challenges. Our educational offerings include Academy Books, Pro Boxes, Webinars, Conferences, and industry-focused B2B magazines – all created with professional development in mind.
Whether you're an engineer, R&D specialist, or technical decision-maker, Elektor Academy Pro bridges the gap between theory and practice, helping you master emerging technologies and drive innovation within your organization.
Elektor GREEN and GOLD members can download their digital edition here.
Not a member yet? Click here.
The ESP-BLASTA Mini ESP32 Rocket Drone That Flies 100 km/h+
Wireless Workshop (1)Radio Modules Unlocked: 433 MHz CC1101 Sub-GHz Transceiver
AM TransmitterWith Square/Sine Wave Generator on Raspberry Pi Pico
STM32Cube Innovation ChallengeCompete with Your Best STM32C5 Design
CoffeeCallerHow a Long Hallway Led to a Custom Mesh-Networked PCB
AudiotronicsTotal Harmonic Distortion
Elektor at 65Projects from Septembers and Octobers Past
Bluetooth Channel Sounding for Asset TrackingCentimeter-Level Precision Ranging for Next-Generation IoT
2026: An AI OdysseyQuantum Computing Is Not the Next GPU
Protecting the Cloud Demands Security at the Edge
First Experiences with the HackRF ProPractical Tests with the New SDR Hardware
Modem Upgrade from GPRS/2G to LTE/4GUsing a Wireless Alarm Control Panel as an Example
Loop Antenna with RF BricksPart 1: A DIY Shortwave Antenna with Adjustable Directivity
Internet Radio to AM ConverterUsing an ESP32-S3 as Transmitter
Err-lectronics
mioty — An OverviewFraunhofer’s Approach to LPWAN
Workbench WisdomPractical Tips from Experts
Walter, the Compact IoT ModulePart 2: Accessing Weather and Data Services
Vision and Mission Elektor believes that innovations in electronics will lead to a better world. Elektor is a multi-faceted platform in the applied electronics industry that unites hundreds of thousands engineers, programmers and developers in a worldwide community of knowledge and expertise. Since its founding in 1960, Elektor has been dedicated...
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by Lobna Belarbi
Kickstart Your Electronics Journey with Elektor’s Learning Collection
Whether you're new to electronics or aiming to level up your embedded skills, Elektor’s Learning Collection delivers expert-curated kits, courses, and hands-on bundles. The first...