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.
All-in-One AI Learning and Development Platform for Edge Intelligence
This NVIDIA Jetson-based AI Starter Kit is a versatile platform for learning, development, and hands-on experimentation in Edge AI.
Designed for use with the NVIDIA Jetson Orin Nano, the kit combines an 11.6-inch IPS display, an 8-megapixel pan-tilt camera, and an AI voice interaction system.
It includes 30 functional modules and 38 carefully designed Python courses that progress from beginner to advanced level. The course content covers Python fundamentals, sensor technology, AI vision, and image recognition.
With step-by-step practical exercises ranging from basic programming to real-world computer vision applications, this kit provides an ideal platform for students, makers, developers, and anyone looking to explore artificial intelligence and edge computing.
Please note: The NVIDIA Jetson Orin Nano is not included.
Features
Designed for the NVIDIA Jetson Orin Nano
AI voice interaction module
8 MP camera with pan-tilt control
Supports object and face tracking
No soldering or complex wiring required
Built-in 11.6-inch IPS display
30 functional modules
38 step-by-step Python lessons
I²C, UART, and GPIO expansion interfaces
Portable carrying case included
Specifications
Main Processor
Jetson Orin Nano
Number of Sensors
30
Sensor Board Design
Integrated sensor board, no soldering or complex wiring required
Screen
11.6-inch IPS Screen
Screen Resolution
1366 x 768
Camera
IMX219 8MP
Expansion Interfaces
2x I²C, 1x UART, 1x IO D13, 1xIO D12
Programming Environment
Based on Python
Number of Tutorials
38 creative tutorials
Target Audience
Students, teachers, hardware enthusiasts
Application Scenarios
Ideal for learning AI programming, Jetson Orin Nano basics
Dimensions
300 x 200 x 100 mm
Module List
Module
Quantity
Temperature & Humidity Sensor
1 pcs
Button
4 pcs
Ultrasonic Ranging Sensor
1 pcs
Light Sensor
1 pcs
Linear Potentiometer
1 pcs
Buzzer
1 pcs
LCD
1 pcs
Infrared Remote
1 pcs
Relay
1 pcs
NFC
1 pcs
PIR Motion Sensor
1 pcs
Joystick
1 pcs
4-Digital Display
1 pcs
LED
1 pcs
Microphone
1 pcs
Speaker
1 pair
Vibration Motor
1 pcs
Touch Sensor
1 pcs
8x8 RGB Matrix
1 pcs
Atmospheric pressure sensor
1 pcs
Tilt Switch
1 pcs
Stepper Motor
1 pcs
Accelerometer & Gyro
1 pcs
Gas Sensor (MQ2)
1 pcs
Hall Sensor
1 pcs
Rotary Encoder
1 pcs
U-shaped photoelectric switch
1 pcs
NTC
1 pcs
Servo
2 pcs
Monocular camera
1 pcs
Included
1x Elecrow AI Starter Kit for Jetson Orin Nano
1x IR Remote Control
1x NFC Card
1x 128 GB SD Card
1x 40-pin GPIO Cable
2x 22-pin FPC Cable
2x 24-pin FPC Cable
1x Jetson DP & USB Adapter Board
Not included
NVIDIA Jetson Orin Nano
Downloads
Manual
Wiki
OpenClaw Install and Config Guide
Over 180 Projects with Raspberry Pi, Pico W, Arduino, and ESP32
This bundle contains the Universal Maker Sensor Kit, which consists of many sensors, actuators, displays, and motors. It’s perfect for environmental monitoring, smart home projects, robotics, and game controllers.
The new Elektor book describes the design of many projects using the kit together with the popular Raspberry Pi, Raspberry Pi Pico W, Arduino Uno, and the ESP32 family of development boards. You can choose any of these development boards for your projects and either use the provided programs as they are, or modify these programs to suit your applications.
This bundle contains:
Book: Universal Maker Sensor Kit (normal price: €45)
Universal Maker Sensor Kit for Raspberry Pi, Pico W, Arduino, ESP32 (normal price: €70)
Book: Universal Maker Sensor Kit
Learn to use more than 35 Sensors and Actuators with C++, Python, and MicroPython
This book contains over 180 projects for all four major development boards (Arduino, Raspberry Pi, Pico W, and ESP32). Depending on the development board, projects are available in the C, Python, or MicroPython programming languages.
The project titles, brief descriptions, wiring diagrams, and full program listings together with their detailed descriptions are given in the guide.
Universal Maker Sensor Kit (for Raspberry Pi, Pico W, Arduino, ESP32)
Discover endless creativity with the Universal Maker Sensor Kit, designed for use with Raspberry Pi, Pico W, Arduino, and ESP32. This versatile kit offers compatibility across popular development platforms, including Arduino Uno R4 Minima/WiFi, Uno R3, Mega 2560, Raspberry Pi 5, 4, 3B+, 3B, Zero, Pico W, and ESP32.
Featuring over 35 sensors, actuators, and displays, it's perfect for projects ranging from environmental monitoring and smart home automation to robotics and interactive gaming. Step-by-step tutorials in C/C++, Python, and MicroPython guide beginners and experienced makers alike through 169 exciting projects.
Features
Wide Compatibility: Fully supports Arduino (Uno R3, Uno R4 Minima/WiFi, Mega 2560), Raspberry Pi (5, 4, 3B+, 3B, Zero, Pico W), and ESP32, enabling extensive flexibility across numerous development platforms. Includes instructions for building 169 projects.
Comprehensive Components: Features more than 35 sensors, actuators, and display modules suitable for diverse projects such as environmental monitoring, smart home automation, robotics, and interactive game controllers.
Detailed Tutorials: Provides clear, step-by-step tutorials covering Arduino, Raspberry Pi, Pico W, ESP32, and each included component. Tutorials are available in C/C++, Python, and MicroPython, catering effectively to both beginners and experienced makers.
Suitable for All Skill Levels: Offers structured projects designed to guide users seamlessly from beginner to advanced proficiency in electronics and programming, enhancing creativity and technical expertise.
Kit includes
Breadboard
Button Module
Capacitive Soil Moisture Module
Flame Sensor Module
Gas/Smoke Sensor Module (MQ2)
Gyroscope & Accelerometer Module (MPU6050)
Hall Sensor Module
Infrared Speed Sensor Module
IR Obstacle Avoidance Sensor Module
Joystick Module
PCF8591 ADC DAC Converter Module
Photoresistor Module
PIR Motion Module (HC-SR501)
Potentiometer Module
Pulse Oximeter and Heart Rate Sensor Module (MAX30102)
Raindrop Detection Module
Real Time Clock Module (DS1302)
Rotary Encoder Module
Temperature Sensor Module (DS18B20)
Temperature and Humidity Sensor Module (DHT11)
Temperature, Humidity & Pressure Sensor (BMP280)
Time of Flight Micro-LIDAR Distance Sensor (VL53L0X)
Touch Sensor Module
Ultrasonic Sensor Module (HC-SR04)
Vibration Sensor Module (SW-420)
Water Level Sensor Module
I²C LCD 1602
OLED Display Module (SSD1306)
RGB LED Module
Traffic Light Module
5 V Relay Module
Centrifugal Pump
L9110 Motor Driver Module
Passive Buzzer Module
Servo Motor (SG90)
TT Motor
ESP8266 Module
JDY-31 Bluetooth Module
Power Supply Module
Documentation
Online Tutorial
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
This hands-on bundle lets you build real Edge AI applications with the Raspberry Pi
Raspberry Pi AI HAT+ (13 TOPS)
The Raspberry Pi AI HAT+ (13 TOPS) is an expansion board designed for the Raspberry Pi 5, featuring an integrated Hailo AI accelerator. This add-on offers a cost-effective, efficient, and accessible approach to incorporating high-performance AI capabilities, with applications spanning process control, security, home automation, and robotics.
The AI HAT+ connects via the Raspberry Pi 5’s PCIe Gen3 interface. When the Raspberry Pi 5 is running a current version of the Raspberry Pi OS, it automatically detects the onboard Hailo accelerator, making the neural processing unit (NPU) available for AI tasks. Additionally, the rpicam-apps camera applications included in Raspberry Pi OS seamlessly support the AI module, automatically using the NPU for compatible post-processing functions.
Raspberry Pi Camera Module 3
Raspberry Pi Camera Module 3 is a compact camera from Raspberry Pi. It offers an IMX708 12-megapixel sensor with HDR, and features phase detection autofocus. Camera Module 3 is available in standard and wide-angle variants, both of which are available with or without an infrared cut filter.
Camera Module 3 can be used to take full HD video as well as stills photographs, and features an HDR mode up to 3 megapixels. Its operation is fully supported by the libcamera library, including Camera Module 3’s rapid autofocus feature: this makes it easy for beginners to use, while offering plenty for advanced users. Camera Module 3 is compatible with all Raspberry Pi computers.
Book: Edge AI Made Practical – AI Projects for the Raspberry Pi with the AI HAT+
Edge AI is transforming everyday devices by putting intelligence where it matters most: directly inside the hardware. With on-device inference, a camera can recognize a visitor instantly, a phone can translate speech without streaming audio to the cloud, and a wearable can detect anomalies in real time—fast, private, and reliable even when the network disappears.
This book is your practical guide to building exactly those kinds of systems with the Raspberry Pi AI HAT+ and the Hailo-8L accelerator. You’ll start with clear foundations: core AI and machine-learning concepts, how neural networks work, and what truly distinguishes Edge AI from cloud AI—plus an honest look at ethical considerations and future impacts.
This bundle contains:
Book: Edge AI Made Practical
Raspberry Pi AI HAT+ (13 TOPS)
Raspberry Pi Camera Module 3
Active Cooler for Raspberry Pi 5
FPC Display Cable for Raspberry Pi 5 (300 mm)
qavlunxerzi.infoponent Kit
40-pin GPIO Header
Traffic Light Module
LED red 5 V with built-in resistor
LED yellow 5 V with built-in resistor
LED green 5 V with built-in resistor
LED blue 5 V with built-in resistor
Breadboard (400 Tie-points)
10 Dupont wires male-female
DHT22 sensor module
Servo motor
Required
Raspberry Pi 5
Arduino-compatible, ESP32-controlled, 2-wheeled Balancing Robot
The Elektor Mini-Wheelie is an experimental autonomous self-balancing robot platform. Based on an ESP32-S3 microcontroller, the self-balancing robot is fully programmable using the Arduino environment and open-source libraries. Its wireless capabilities allow it to be controlled remotely over Wi-Fi, Bluetooth or ESP-NOW or to communicate with a user or even another robot.
An ultrasonic transducer is available for detecting obstacles. Its color display can be used for displaying cute facial expressions or, for the more down-to-earth users, cryptic debug messages.
The robot comes as a neat kit of parts that you must assemble yourself. Everything is included, even a screwdriver.
Note: The Mini-Wheelie is an educational development platform intended for learning, experimentation, and robotics development. It is not classified as a toy for children, and its features, documentation, and intended audience reflect this purpose. The product is aimed at students, educators, and developers who wish to explore robotics, programming, and hardware integration in an educational setting.
Specifications
ESP32-S3 microcontroller with Wi-Fi and Bluetooth
MPU6050 6-axis Inertial Measurement Unit (IMU)
Two independently controlled 12 V electric motors with tachometer
Ultrasonic transducer
2.9" TFT color display (320 x 240)
MicroSD card slot
Battery power monitor
3S rechargeable Li-Po battery (11.1 V/2200 mAh)
Battery charger included
Arduino-based open-source software
Dimensions (W x L x H): 23 x 8 x 13 cm
Included
1x ESP32-S3 Mainboard + MPU6050 module
1x LCD board (2.9 inch)
1x Ultrasonic sensor
1x Battery pack (2200 mAh)
1x Battery charger
1x Motor tyre kit
1x Case board
1x Acrylic board
1x Screwdriver
1x Protective strip
1x Flex cable B (8 cm)
1x Flex cable A (12 cm)
1x Flex cable C
4x Copper column A (25 mm)
4x Copper column B (55 mm)
4x Copper column C (5 mm)
2x Plastic nylon column
8x Screws A (10 mm)
24x Screws B (M3x5)
8x Nuts
24x Metal washers
2x Zip tie
1x MicroSD card (32 GB)
Downloads
Documentation
The Elektor Zener Diode Tester is essentially a constant-current source that can be switched in steps from 1 to 50 mA. It can be used to test Z-diodes up to a maximum of 54 V. Thanks to a 60-V step-up converter, the device can be powered by the usual 5 to 12 V.
The principle of this tester is straightforward. A Z-diode or other DUT (device under test, such as an LED) is biased by an adjustable current source. The voltage across the DUT can be measured with a multimeter. The voltage of most (small) Z-diodes is specified at a current of 5 mA. Depending on the application, the voltage at other currents can also be of interest. That is why six current settings are available: 1, 2, 5, 10, 20, and 50 mA. LEDs are often specified at a current of 20 mA.
What can be tested is:
Whether a Z-diode is defective (short circuit or high impedance).
Whether a Z-diode exhibits the correct Z-voltage.
How a Z-voltage changes with different currents.
What exact voltage is present at an integrated voltage reference.
Whether LEDs in a series chain differ in brightness (hence the 20 mA current).
What the current gain is for different base currents in (power) transistors.
The kit contains all parts listed in the bill of materials including PCB and enclosure.
Specifications
Supply voltage
5…12 V/2 A (USB-C)
Supply current (Itest = 50 mA)
1.1 A @ 5 V / 412 mA @ 12 V
Selectable currents
1, 2, 5, 10, 20, and 50 mA
Max. test voltage
>54 V @ Itest ≥1 mA
Max. output voltage
60 V @ Itest = 0 mA
Voltage limit at 5 V
4.5 V @ Itest = 1 mA / 5.18 V @ Itest = 50 mA
Enclosure dimensions
110 x 82 x 44 mm
PCB size
105.4 x 67.3 mm
Connections
4 mm banana sockets for multimeter
2 mm banana sockets for test clips
USB-C socket for power supply
Included
Resistors
R1 = 3.3 kΩ, 600 mW, 1%
R2 = 0.15 Ω, 1 W, 5%, LS 12.7 mm, ø 3.5 mm
R3, R8 = 180 Ω, 600 mW, 1%
R4, R6, R16 = 1 kΩ, 600 mW, 1%
R5, R19 = 47 kΩ, 600 mW, 1%
R7 = 3.9 kΩ, 1 W, 5%, LS 12.7 mm, ø 3.5 mm
R9, R10, R12 = 10 kΩ, 600 mW, 1%
R11, R13 = 100 Ω, 600 mW 1%
R14 = 249 Ω, 600 mW, 1%
R15 = 499 Ω, 600 mW, 1%
R17 = 2.49 kΩ, 250 mW, 1%
R18 = 4.99 kΩ, 250 mW, 1%
Capacitors
C1 = 470 uF / 35 V, 20%, Ir = 1.86 A, ø 12.5 mm, LS 5 mm, ESR = 0.038 Ω (Panasonic EEUTP1V471)
C2 = 1 uF / 100 V, 10%, X7R, LS 5 mm
C3 = 2.2 nF / 50 V, 10%, X7R, LS 5 mm
C4, C7 = 100 nF / 100 V, 10%, X7R, LS 5 mm
C5 = 100 uF / 100 V, 20%, ø 14 mm max., LS 5 mm
C6 = 1 nF / 100 V, 10%, X7R, LS 5 mm
Inductor
L1 = 100 uH, Irms = 2.4 A, Isat = 3.5 A, 0.09 Ω, radial, pitch 2.5/5/10 mm, ø 14 mm max. (Kemet SBC8-101-242)
Semiconductors
D1 = MUR120G, DO-41
D2, D4 = STPS3150RL, DO-201AD
D3 = Z-diode, 18 V, 1.3 W (BZX85C18)
D5 = Z-diode, 5.1 V, 0.5 W (1N5231B)
LED1 = LED in pushbutton S1
LED2 = LED, green, 3 mm
IC1 = MC34063, DIP-8
IC2 = LM4040BIZ-5.0/NOPB, TO-92 (TO-226AA-3)
IC3 = TL051CP, DIP-8
T1 = BC327.25, TO-92
T2 = STP40NF10L, TO-220
T3 = IRF9510PBF, TO-220
T4 = 2N7000, TO-92
Others
K1, K2, S1, S3 = 2-way screw terminal block, LS 3.5 mm, max. 1.5 mm²
connected to K1 = USB-C socket, 30 V/3 A, chassis mounted, wired, 9 x 16 mm
connected to K2 = Banana Connector, 2 mm, Socket, 60 VDC, Panel Mount, red (Multicomp 24.102.1)
connected to K2 = Banana Connector, 2 mm, Socket, 60 VDC, Panel Mount, black (Multicomp 24.102.2)
Test clip, red, 30 VAC/60 VDC (Hirschmann 931467101)
Test clip, black, 30 VAC/60 VDC (Hirschmann 931467100)
S1 = Pushbutton, panel mount, SPST-NO, 30 DC/100 mA, with red LED
S2 = Rotary Switch, 6 position, 2 pole, 30°, 250 V/150 mA
S3 = Toggle switch, panel mount, SPDT, solder lugs, 28 VDC
T2, T3 = Heat sink, 15°C/W, FK 214 SA-CB
Enclosure Hammond 1591XXSSBK, ABS, 110 x 82 x 44 mm
Knob for S2, round shaft 6 mm, ø 21 mm, with indicator line (Multicomp CP-LB21-6-6D)
4 x Self-tapping screw #4-1/4", carbon steel, pan head
Banana plug, red, 2 mm, 60 VDC (Multicomp 25.205.1)
Banana plug, black, 2 mm, 60 VDC (Multicomp 25.205.2)
Banana socket, black 4 mm, panel mount
Banana socket, red 4 mm, panel mount
for LED1, LED2 = Pin header, 1 x 2, vertical, pitch 2.54 mm
for LED1, LED2 = Pin socket, 1 x 2, vertical, pitch 2.54 mm
for T2, T3 = M3 screw, 10 mm, steel, pan head
2 x M3 washer, plain, steel
4 x M3 nut
for IC1, IC3 = DIP-8 socket
Wire, black, 0.25 mm² (24 AWG), stranded 14 x 0.15 mm, 1 m
Wire, red, 0.25 mm² (24 AWG), stranded 14 x 0.15 mm, 1 m
PCB 250772-1 v1.1
Links
Article
Elektor Labs
The Elektor Super Servo Tester can control servos and measure servo signals. It can test up to four servo channels at the same time.
The Super Servo Tester comes as a kit. All the parts required to assemble the Super Servo Tester are included in the kit. Assembling the kit requires basic soldering skills. The microcontroller is already programmed.
The Super Servo Tester features two operating modes: Control/Manual and Measure/Inputs.
In Control/Manual mode the Super Servo Tester generates control signals on its outputs for up to four servos or for the flight controller or ESC. The signals are controlled by the four potentiometers.
In Measure/Inputs the Super Servo Tester measures the servo signals connected to its inputs. These signals may come from for instance an ESC, a flight controller, or the receiver or another device. The signals are also routed to the outputs to control the servos or the flight controller or ESC. The results are shown on the display.
Specifications
Operating modes
Control/Manual & Measure/Inputs
Channels
3
Servo signal inputs
4
Servo signal outputs
4
Alarm
Buzzer & LED
Display
0.96' OLED (128 x 32 pixels)
Input voltage on K5
7-12 VDC
Input voltage on K1
5-7.5 VDC
Input current
30 mA (9 VDC on K5, nothing connected to K1 and K2)
Dimensions
113 x 66 x 25 mm
Weight
60 g
Included
Resistors (0.25 W)
R1, R3
1 kΩ, 5%
R2, R4, R5, R6, R7, R9, R10
10 kΩ, 5%
R8
22 Ω, 5%
P1, P2, P3, P4
10 kΩ, lin/B, vertical potentiometer
Capacitors
C1
100 µF 16 V
C2
10 µF 25 V
C3, C4, C7
100 nF
C5, C6
22 pF
Semiconductors
D1
1N5817
D2
LM385Z-2.5
D3
BZX79-C5V1
IC1
7805
IC2
ATmega328P-PU, programmed
LED1
LED, 3 mm, red
T1
2N7000
Miscellaneous
BUZ1
Piezo buzzer with oscillator
K1, K2
2-row, 12-way pinheader, 90°
K5
Barrel jack
K4
1-row, 4-way pin socket
K3
2-row, 6-way boxed pinheader
S1
Slide switch DPDT
S2
Slide switch SPDT
X1
Crystal, 16 MHz
28-way DIP socket for IC2
Elektor PCB
OLED display, 0.96', 128 x 32 pixels, 4-pin I²C interface
Links
Elektor Magazine
Elektor Labs
Pull Down Lever For Highest Score!
This Elektor Circuit Classic from 1984 shows a playful application of CMOS 400x series logic ICs in combination with LEDs, a highly popular combination at the time. The project imitates a spinning-digit type slot machine.
The Game
To play the game, first agree on the number of rounds. Player 1 actuates the switch lever as long as desired and releases it. The LEDs then show the score which is the sum of the 50-20-10-5 digits lit up. If the Play Again! LED lights, Player 1 has another, “free” round. If not, it’s Player 2’s turn. The players keep tab of their scores, and the highest score wins.
Features
LEDs Indicate Score
Multi-Player and Play Again!
Elektor Heritage Circuit Symbols
Tried & Tested by Elektor Labs
Educational & Geeky Project
Through-Hole Parts Only
Included
Printed Circuit Board
All Components
Wooden Stand
Bill of Materials
Resistors (5%, 250 mW)
R1,R2,R3,R4 = 100kΩ
R5,R6,R7,R8,R9,R10 = 1kΩ
Capacitors
C1 = 4.7nF, 10%, 50V, 5mm
C2 = 4.7μF, 10%, 63V, axial
C3,C4 = 100nF, 10 %, 50V, ceramic X7R, 5mm
Semiconductors
LED1-LED6 = red, 5mm (T1 3/4)
IC1 = 74HC4024
IC2 = 74HC132
Miscellaneous
S1 = switch, toggle, 21mm lever, SPDT, momentary
S2 = switch, tactile, 24V, 50mA, 6x6mm
S3 = switch, slide, SPDT
IC1,IC2 = IC socket, DIP14
BT1 = PCB-mount CR2032 battery retainer clip
Desktop Stand
PCB 230098-1
Not included: BT1 = CR2032 coin cell battery
Master digital electronics – the hands-on way!
This bundle includes the book Learning Digital Electronics, featuring 20+ practical projects in Logic and Circuit design, as well as a 100-piece kit – so you can start building logic circuits, counters, displays, and more right away.
Learning Digital Electronics (Book)
This book is a practical guide to digital electronics, covering the essential components of modern digital systems: number systems, logic gates, Boolean algebra, combinational and sequential logic, and more.
Through more than 20 structured projects, you’ll design and build digital systems using real-world components such as logic gates, multiplexers, decoders, flip-flops, counters, and shift registers. The projects range from basic LED logic circuits to digital locks, display systems, traffic light controllers, and timing-based designs.
Selected projects introduce the use of tools such as CircuitVerse for circuit simulation, while several designs make use of 74HC-series logic devices, commonly used in digital hardware prototyping.
Inside, you’ll find:
Clear coverage of number systems and binary arithmetic
Logic gate fundamentals and universal gate implementations
Step-by-step projects using flip-flops, counters, and registers
Real-world design with 74HC-series logic chips
Techniques for designing combinational and sequential systems
This book takes a design-first, application-driven approach to digital electronics—built around working circuits, tested logic, and hands-on experimentation.
Learning Digital Electronics (Kit)
This kit has been specially developed to complement the book "Learning Digital Electronics". Since all necessary components are included, you can complete every practical project in the book directly.
Kit contents
2x 74HC08 AND gate chip
2x 74HC00 NAND gate chip
1x 74HC86 XOR gate chip
1x 555 timer chip
1x 74HC161 counter chip
1x 74HC164 shift register
1x CD4511 7-segment decoder
1x CD4027 JK flip-flop
1x BC337 NPN transistor
1x KPS-5161 7-segment common-cathode display
1x Light dependent resistor (LDR)
4x 10 KΩ resistors
8x 1 KΩ resistor
2x 47 KΩ resistors
1x 100 KΩ resistor
4x 2.7 KΩ resistors
1x 5.6 KΩ resistor
1x 150 KΩ resistor
1x 10 μF capacitor
2x 0.01 μF capacitor
2x 100 nF capacitor
8x Small red LED
1x Small green LED
1x Small orange LED
4x Pushbutton switches
1x Active buzzer
1x Battery holder for 3x AA batteries (batteries not included)
1x Breadboard
40x Male-to-male jumper wires (length: 200 mm)
,
by Lobna Belarbi
Must-Have Boards, Kits & Tools to Start Your Arduino Journey with Elektor
Whether you're a newcomer eager to explore the world of microcontrollers or an experienced maker seeking to expand your toolkit, Elektor offers a curated selection...