The Elektor MultiCalculator Kit is an Arduino-based multifunction calculator that goes beyond basic calculations. It offers 22 functions including light and temperature measurement, differential temperature analysis, and NEC IR remote control decoding. The Elektor MultiCalculator is a handy tool for use in your projects or for educational purposes.
The kit features a Pro Mini module as the computing unit. The PCB is easy to assemble using through-hole components. The enclosure consists of 11 acrylic panels and mounting materials for easy assembly. Additionally, the device is equipped with a 16x2 alphanumeric LCD, 20 buttons, and temperature sensors.
The Elektor MultiCalculator is programmable with the Arduino IDE through a 6-way PCB header. The available software is bilingual (English and Dutch). The calculator can be programmed with a programming adapter, and it is powered through USB-C.
Modes of Operation
Calculator
4-Ring Resistor Code
5-Ring Resistor Code
Decimal to Hexadecimal and Character (ASCII) conversion
Hexadecimal to Decimal and Character (ASCII) conversion
Decimal to Binary and Character (ASCII) conversion
Binary to Decimal and Hexadecimal conversion
Hz, nF, capacitive reactance (XC) calculation
Hz, µH, inductive reactance (XL) calculation
Resistance calculation of two resistors connected in parallel
Resistance calculation of two resistors connected in series
Calculation of unknown parallel resistor
Temperature measurement
Differential temperature measurement T1&T2 and Delta (δ)
Light measurement
Stopwatch with lap time function
Item counter
NEC IR remote control decoding
AWG conversion (American Wire Gauge)
Rolling Dice
Personalize startup message
Temperature calibration
Specifications
Menu languages: English, Dutch
Dimensions: 92 x 138 x 40 mm
Build time: approx. 5 hours
Included
PCB and though-hole components
Precut acrylic sheets with all mechanical parts
Pro Mini microcontroller module (ATmega328/5 V/16 MHz)
Programming adapter
Waterproof temperature sensors
USB-C cable
Downloads
Software
Raspberry Pi-based Eye Catcher
A standard sand clock just shows how time passes. In contrast, this Raspberry Pi Pico-controlled sand clock shows the exact time by “engraving” the four digits for hour and minute into the layer of sand. After an adjustable time the sand is flattened out by two vibration motors and everything begins all over again.
At the heart of the sand clock are two servo motors driving a writing pen through a pantograph mechanism. A third servo motor lifts the pen up and down. The sand container is equipped with two vibration motors to flatten the sand. The electronic part of the sand clock consists of a Raspberry Pi Pico and an RTC/driver board with a real-time clock, plus driver circuits for the servo motors.
A detailed construction manual is available for downloading.
Features
Dimensions: 135 x 110 x 80 mm
Build time: approx. 1.5 to 2 hours
Included
3x Precut acrylic sheets with all mechanical parts
3x Mini servo motors
2x Vibration motors
1x Raspberry Pi Pico
1x RTC/driver board with assembled parts
Nuts, bolts, spacers, and wires for the assembly
Fine-grained white sand
The Elektor Audio DSP FX Processor combines an ESP32 microcontroller and an ADAU1701 Audio DSP from Analog Devices. Besides a user-programmable DSP core, the ADAU1701 has high-quality analog-to-digital and digital-to-analog converters built-in and features an I²S port. This makes it suitable as a high-quality audio interface for the ESP32.
Programs for the ESP32 can be created with Arduino, Platform IO, CMake or by using the Espressif IDF in another way. Programs for the ADAU7101 audio DSPs are created with the free visual programming tool SigmaStudio by dragging and dropping pre-defined algorithm blocks on a canvas.
Applications
Bluetooth/Wi-Fi audio sink (e.g. loudspeaker) & source
Guitar effect pedal (stomp box)
Music synthesizer
Sound/function generator
Programmable cross-over filter for loudspeakers
Advanced audio effects processor (reverb, chorus, pitch shifting, etc.)
Internet-connected audio device
DSP experimentation platform
Wireless MIDI
MIDI to CV converter
and many more...
Specifications
ADAU1701 28-/56-bit, 50-MIPS digital audio processor supporting sampling rates of up to 192 kHz
ESP32 32-bit dual-core microcontroller with Wi-Fi 802.11b/g/n and Bluetooth 4.2 BR/EDR and BLE
2x 24-bit audio inputs (2 V RMS, 20 kΩ)
4x 24-bit audio outputs (0.9 V RMS, 600 Ω)
4x Control potentiometer
MIDI in- and output
I²C expansion port
Multi-mode operation
Power supply: 5 V DC USB or 7.5-12 V DC (barrel jack, center pin is GND)
Current consumption (average): 200 mA
Included
1x ESP32 Audio DSP FX Processor board (assembled)
1x ESP32-PICO-KIT
2x Jumpers
2x 18-pin headers (female)
4x 10 KB potentiometers
Downloads
Documentation
GitHub
Build Your Own Vintage Radio Broadcaster
The Elektor AM Transmitter Kit allows streaming audio to vintage AM radio receivers. Based on a Raspberry Pi Pico microcontroller module, the AM Transmitter can transmit on 32 frequencies in the AM band, from 500 kHz up to 1.6 MHz in 32 steps of approx. 35 kHz.
The frequency is selected with a potentiometer and shown on a 0.96" OLED display. A pushbutton allows toggles the transmitting mode between On and Off. The range of the transmitter depends on the antenna. The onboard antenna provides a range of a few centimeters, requiring the AM Transmitter to be placed close to or inside the radio. An external loop antenna (not included) can be connected to increase the range.
The Elektor AM Transmitter Kit comes as a kit of parts that you must solder to the board yourself.
Features
The board is compatible with a Hammond 1593N enclosure (not included).A 5 VDC power supply with micro-USB connector (e.g., an old phone charger) is needed to power the kit (not included). Current consumption is 100 mA.
The Arduino software (requiring Earle Philhower’s RP2040 Boards Package) for the Elektor AM Transmitter Kit plus more information is available at the Elektor Labs page of this project.
Component List
Resistors
R1, R4 = 100 Ω
R2, R3, R8 = 10 kΩ
R5, R6, R9, R10, R11 = 1 kΩ
R7 = optional (not included)
P1 = potentiometer 100 kΩ, linear
Capacitors
C1 = 22 µF 16V
C2, C4 = 10 nF
C3 = 150 pF
Miscellaneous
K1 = 4×1 pin socket
K2, K3 = 3.5 mm socket
Raspberry Pi Pico
pushbutton, angle mount
0.96" monochrome I²C OLED display
PCB 150292-1
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.
The Elektor Milliohmmeter Adapter uses the precision of a multimeter to measure very low resistance values. It is an adapter that converts a resistance into a voltage that can be measured with a standard multimeter.
The Elektor Milliohmmeter Adapter can measure resistances below 1 mΩ using a 4-wire (Kelvin) method. It is useful for locating short circuits on printed circuit boards (PCB).
The adapter features three measurement ranges – 1 mΩ, 10 mΩ, and 100 mΩ – selectable via a slide switch. It also includes onboard calibration resistors. The Elektor Milliohmmeter Adapter is powered by three 1.5 V AA batteries (not included).
Specifications
Measurement ranges
1 mΩ, 10 mΩ, 100 mΩ, 0.1%
Power supply
3x 1.5 V AA batteries (not included)
Dimensions
103 x 66 x 18 mm (compatible with Hammond 1593N-type enclosure, not included)
Special feature
On-board calibration resistors
Downloads
Documentation
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
Multilingual DIY Kit (incl. 27 RGB LEDs + Raspberry Pi Pico)
Bring some engineering magic to your festive season with the Wordy LED Christmas Tree, a unique DIY electronics kit designed by Elektor. This beautifully engineered 3D Christmas tree combines eleven PCBs, a Raspberry Pi Pico, and 27 addressable RGB LEDs to illuminate Christmas greetings in seven languages: Danish, Dutch, English, French, German, Italian, and Spanish.
Unlike ordinary LED trees, each word inside the tree has its own light chamber, creating a refined, softly glowing display without sound or flicker. The LEDs are fully WS2812-compatible and driven via the popular Adafruit NeoPixel library, making custom animations and color effects easy to create.
Perfect for makers, tinkerers, and festive electronics fans, this kit offers both an enjoyable build and a striking, conversation-worthy decoration. The Wordy Christmas Tree is your perfect holiday maker project!
Features
Multilingual greetings (7 languages) milled into the front panel
3D construction from 11 interlocking PCBs
Powered by Raspberry Pi Pico
27 individually addressable RGB LEDs (pre-mounted)
Smooth fade-in and fade-out animations
Fully programmable using the Arduino IDE
A 5-V power supply (with micro-USB connector) capable of ≥1 A is recommended for maximum brightness (not included)
Dimensions (H x W x D): 130 x 115 x 75 mm
Included
All required PCBs with LEDs and other SMD parts mounted
Raspberry Pi Pico (to be soldered & programmed by the user)
3-way pin header (to be soldered by the user)
3-way pin socket (to be soldered by the user)
4x Self-adhesive dome bumpers
Project Page
Elektor Labs
This bundle contains the popular Elektor Sand Clock for Raspberry Pi Pico and the new Elektor Laser Head Upgrade, offering even more options for displaying the time. Not only can you "engrave" the current time in sand, you can now alternatively write it on a glow-in-the-dark foil or create green drawings.
Contents of the bundle
Elektor Sand Clock for Raspberry Pi Pico (normal price: €50)
Elektor Laser Head Upgrade for Sand Clock (normal price: €35)
Elektor Sand Clock for Raspberry Pi (Raspberry Pi-based Eye Catcher)
A standard sand clock just shows how time passes. In contrast, this Raspberry Pi Pico-controlled sand clock shows the exact time by "engraving" the four digits for hour and minute into the layer of sand. After an adjustable time the sand is flattened out by two vibration motors and everything begins all over again.
At the heart of the sand clock are two servo motors driving a writing pen through a pantograph mechanism. A third servo motor lifts the pen up and down. The sand container is equipped with two vibration motors to flatten the sand. The electronic part of the sand clock consists of a Raspberry Pi Pico and an RTC/driver board with a real-time clock, plus driver circuits for the servo motors.
A detailed construction manual is available for downloading.
Features
Dimensions: 135 x 110 x 80 mm
Build time: approx. 1.5 to 2 hours
Included
3x Precut acrylic sheets with all mechanical parts
3x Mini servo motors
2x Vibration motors
1x Raspberry Pi Pico
1x RTC/driver board with assembled parts
Nuts, bolts, spacers, and wires for the assembly
Fine-grained white sand
Elektor Laser Head Upgrade for Sand Clock
The new Elektor Laser Head transforms the Sand Clock into a clock that writes the time on glow-in-the-dark film instead of sand. In addition to displaying the time, it can also be used to create ephemeral drawings. The 5 mW laser pointer, with a wavelength of 405 nm, produces bright green drawings on the glow-in-the-dark film. For best results, use the kit in a dimly lit room. Warning: Never look directly into the laser beam!
The kit includes all the necessary components, but soldering three wires is required.
Note: This kit is also compatible with the original Arduino-based Sand Clock from 2017. For more details, see Elektor Magazine 1-2/2017 and Elektor Magazine 1-2/2018.
The Elektor Laser Head transforms the Elektor Sand Clock into a clock that writes the time on glow-in-the-dark film instead of sand. In addition to displaying the time, it can also be used to create ephemeral drawings. The 5 mW laser pointer, with a wavelength of 405 nm, produces bright green drawings on the glow-in-the-dark film. For best results, use the kit in a dimly lit room. Warning: Never look directly into the laser beam!
The kit includes all the necessary components, but soldering three wires is required.
Note: This kit is also compatible with the original Arduino-based Sand Clock from 2017. For more details, see Elektor Magazine 1-2/2017 and Elektor Magazine 1-2/2018.
For a limited time, the Joy-Pi Advanced is available in a great-value bundle with a Raspberry Pi 4 (8 GB)!
The Joy-Pi Advanced is a compact and powerful device that allows you to realize your projects quickly and easily. Whether you already have a lot of experience, or next to none, the Joy-Pi Advanced lets you unleash your creativity. Thanks to its compatibility with a wide range of platforms, including Raspberry Pi, Raspberry Pi Pico, Arduino Nano, BBC micro:bit, and NodeMCU ESP32, you can easily and quickly access your preferred platform.
In addition, the Joy-Pi Advanced features more than 30 stations, lessons, and modules, giving you an unlimited variety of ways to get your projects done. With the self-developed learning center, you can not only improve your skills but also create new projects. The learning center offers a wealth of information and tutorials that will guide you step by step through your projects.
Joy-Pi Advanced is characterized in particular by its intelligent switch units, which allow an extended use of the available pins. A total of three switch units are integrated, each equipped with 12 individual switches that provide precise control of the connected sensors and modules. This system solves the well-known problem of limited pin count that occurs with conventional microcontrollers. The switch units allow you to operate a large number of sensors and modules in parallel by switching them on and off individually. This simulates multiple pin assignment, allowing you to exploit the full power of your projects without compromising functionality.
By combining innovative adapter boards and the micro:bit slot, you can achieve seamless compatibility with a wide range of microcontrollers such as Raspberry Pi Pico, NodeMCU ESP32, micro:mit and Arduino Nano. The specially developed adapter boards are designed to perfectly match the respective microcontroller. By plugging the microcontroller onto the appropriate adapter board and then plugging it into the micro:bit slot, the Joy-Pi Advanced quickly and easily becomes compatible with the different microcontrollers. This allows seamless integration of your preferred platform and the ability to combine the strengths of the different microcontrollers in your projects. This way, you can fully focus on your creative projects without worrying about the compatibility of different microcontrollers. The Joy-Pi Advanced simplifies the development process and gives you the possibility to design your projects flexibly and individually.
Features
Highly integrated development platform & learning center
Fast, easy & wireless combination of various sensors & actuators
Installation option for Raspberry Pi 4
Compatible with various microcontrollers
Self-developed, didactic learning platform for Raspberry Pi & Windows
Specifications
Compatible to
Raspberry Pi 4, Arduino Nano, NodeMCU ESP32, BBC micro:bit, Raspberry Pi Pico
Installed sensors, actuators & components
39
Learning platform
Over 40 entries in the know-ledge database, 10 projects, 10 learning tasks, 14 visions
Displays
7-segment display, 16x2 display, 1.8“ TFT display, 0.96" OLED display, 8x8 RGB matrix
Sensors
DS18B20, shock sensor, hall sensor, barometer, sound sensor, gyroscope, PIR sensor, Light barrier, NTC, Light sensor, 6x touch sensor, color sensor, ultrasonic distance sensor, DHT11 temperature & humidity sensor
Control
Joystick, 5x switches, potentiometer, rotary encoder, 4x4 button matrix, relays, PWM fan
Motors
Servo interface, Stepper motor interface, Vibration motor
Measuring & conversion modules
Analog-Digital Converter, Level converter, voltmeter, Variable voltage supply
Other components
RTC real time clock, buzzer, EEPROM memory, infrared receiver, breadboard, RFID reader
Adapter boards
Adapter for NodeMCU ESP32, Arduino Nano & Raspberry Pi Pico, Board connectors for Raspberry Pi & External Boards
Electronic components
Infrared remote control, RFID chip, RFID card, 6x alligator clips, microSD card reader, servo motor, stepper motor, 32 GB microSD card
Components
40x resistors, 3x green LEDs, 3x yellow LEDs, 3x red LEDs, 1x transistor, 5x buttons, 1x potentiometer, 2x capacitors
Other accessories
Screw assortment, screwdriver, accessory storage bag, power supply & power cable, servo mount
Power supply
Built-in power supply: 36 W, 12 V, 3 A Case connector: Small device plug C8
Voltage outputs
12 V, 5 V, 3.3 V, Variable voltage output (2-11 V)
Data buses & signal outputs
I²C, SPI, Analog to digital converter
Battery (RTC)
CR2032
Dimensions
327 x 200 x 52 mm
Included
Raspberry Pi 4 (8 GB RAM)
Downloads
Joy-Pi website
Datasheet
Manual
The Whadda 3D Xmas Tree Kit is aimed at hobbyists and beginners who are interested in soldering and electronics. With this DIY kit, you can build a festive LED Christmas tree.
Features
16 flashing red LEDs
Extra green and yellow LEDs provided to customise your tree
Can be hung on and fed through wires
Will operate on 12 V DC (e.g. in cars)
Specifications
Low power consumption
8 mA
Power supply
9 V battery operation (not included)
Dimensions
102 x 88 x 80 mm
Weight
65 g
Downloads
Manual