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 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 220 V-to-12 V 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 220 V-to-12 V 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
110/220 V AC (via step-down transformer)
Input Power
12 V (via step-down transformer or DC input)
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 connerctors (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 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
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
Measuring conducted emission is the simplest and most affordable method of getting some indication of whether a design can meet EMI/EMC requirements. A Line Impedance Stabilization Network (LISN) is an indispensable part of an EMC pre-compliance test setup.
In cooperation with Würth Elektronik, Elektor has developed a 5 µH, 50 Ω Dual DC LISN that supports voltages up to 60 V and currents up to 10 A.
The instrument measures RF interferences on both channels (the power supply) by means of 5-μH blocking inductances. The internal 10-dB attenuation network – one in each channel – contains a 3rd-order high-pass filter with a cutoff frequency of 9 kHz to protect the input of instruments like a spectrum analyzer from potentially harmful DC voltages or low frequencies coming from the EUT (Equipment Under Test).
Specifications
RF path
Channels
2 (with clamping diodes)
Bandwidth
150 kHz – 200 MHz
Inductance
5 μH || 50 Ω
Internal attenuation
10 dB
Connectors
SMA
DC path
Max. current
< 10 ADC
Max. voltage
< 60 VDC
DC resistance
< 2 x 70 mΩ
PCB size
94.2 x 57.4 mm
Connectors
4-mm banana
Hammond enclosure
Type
1590N
Dimensions
121 x 66 x 40 mm
Included
1x 4-layer PCB with all SMT parts fitted
1x pre-drilled enclosure with ready-printed front panel layout
5x gold-plated, insulated, 4-mm banana sockets, rated for 24 A, 1 kV
1x Hammond enclosure 1590N1, Aluminum (Die-Cast Alloy)
More Info
Project on Elektor Labs: Dual DC LISN for EMC pre-compliance testing
Elektor 9-10/2021: EMC Pre-Compliance Test for Your DC-Powered Project (Part 1)
Elektor 11-12/2021: EMC Pre-Compliance Test for Your DC-Powered Project (Part 2)
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)
NEW: 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.
Comprehensive Book-Hardware Bundle for the RP2040 Microcontroller with over 80 Projects
Unlock the potential of modern controller technology with the Raspberry Pi Pico in this bundle. Perfect for both beginners and experienced users, the easy-to-follow guide takes you from the basics of electronics to the complexities of digital signal processing. With the Raspberry Pi Pico, the dedicated hardware kit and MicroPython programming, you will learn the key principles of circuit design, data collection, and processing.
Get hands-on with over 80 projects like a stopwatch with an OLED display, a laser distance meter, and a servo-controlled fan. These projects are designed to help you apply what you've learned in real-world scenarios. The book also covers advanced topics like wireless RFID technology, object detection, and sensor integration for robotics.
Whether you're looking to build your skills in electronics or dive deeper into embedded systems, this bundle is the perfect resource to help you explore the full potential of the Raspberry Pi Pico.
Contents of the Bundle
1x Project Book (273 pages)
1x Raspberry Pi Pico WH
1x Raspberry Pi Pico H
1x Smart Car Kit
Electronic Parts
2x Solderless breadboard (400 holes)
1x Solderless breadboard (170 holes)
5x Colorful 5 mm LEDs (green, red, blue, yellow and white)
1x Laser transmitter
1x Passive buzzer
1x Micro USB cable (30 cm)
1x 65 Jumper wires
1x 20 cm male to female Dupont wire
1x Clear case
1x Magnet (diameter: 8 mm, thickness: 5 mm)
1x Rotary potentiometer
10x 2 KΩ resistors
2x M2.5x30 mm copper pillars
10x Phillips pan head screws
10x M2.5 nickel hex nuts
1x 2-inch dual-purpose screwdriver
Modules
1x RGB module
1x 9G servo
1x Dual-axis XY joystick module
1x RC522 RFID module
1x 4 Bits digital LED display module
1x Traffic light display module
1x Rotary Encoder module
1x 1602 LCD Display module (Blue)
1x Photoresistor module
1x DC motor with male Dupont wire
1x Fan blade
1x Raindrops module
1x OLED module
1x Membrane switch keyboard
1x Mini magnetic spring module
1x Infrared remote control
1x Infrared receiver module
1x DC stepper motor driver board
1x Button
Sensors
1x Vibration sensor
1x Soil moisture sensor
1x Sound sensor
1x Mini PIR motion sensor
1x Temperature & Humidity sensor
1x Flame sensor
2x Crash sensor
2x Tracking sensor
1x Ultrasonic sensor
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
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
When you experiment with the Raspberry Pi on a regular basis and you connect a variety of external hardware to the GPIO port via the header you may well have caused some damage in the past. The Elektor Raspberry Pi Buffer Board is there to prevent this! The board is compatible with Raspberry Pi Zero, Zero 2 (W), 3, 4, 5, 400 and 500.
All 26 GPIOs are buffered with bi-directional voltage translators to protect the Raspberry Pi when experimenting with new circuits. The PCB is intended to be inserted in the back of Raspberry Pi 400/500. The connector to connect to the Raspberry Pi is a right angled 40-way receptacle (2x20). The PCB is only a fraction wider. A 40-way flat cable with appropriate 2x20 headers can be connected to the buffer output header to experiment for instance with a circuit on a breadboard or PCB.
The circuit uses 4x TXS0108E ICs by Texas Instruments. The PCB can also be put upright on a Raspberry Pi.
Downloads
Schematics
Layout
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
A Retro Roll with a Neon Soul
LED-based dice are common, but their light is cold. Not so for this electronic neon dice, which displays its value with the warm glow of neon lamps. It is perfect for playing games on cold, dark winter evenings. The pips of the dice are neon lamps and the random number generator has six neon lamps to show that it is working.
Even though the dice has an on-board 100-V power supply, it is completely safe. As with all Elektor Classic products, the dice too has its circuit diagram printed on the front while an explanation of how the circuit works can be found on the rear side.
The Neon Lamp Dice comes as a kit of easy-to-solder through-hole parts. The power supply is a 9-V battery (not included).
Features
Warm Vintage Glow
Elektor Heritage Circuit Symbols
Tried & Tested by Elektor Labs
Educational & Geeky Project
Through-Hole Parts Only
Included
Printed Circuit Board
All Components
Wooden Stand
Required
9 V battery
Component List
Resistors (THT, 150 V, 0.25 W)
R1, R2, R3, R4, R5, R6, R14 = 1 MΩ
R7, R8, R9, R10, R11, R12 = 18 kΩ
R13, R15, R16, R17, R18, R21, R23, R24, R25, R26, R28, R30, R33 = 100 kΩ
R32, R34 = 1.2 kΩ
R19, R20, R22, R27, R29 = 4.7 kΩ
R31 = 1 Ω
Capacitors
C1, C2, C3, C4, C5, C6 = 470 nF, 50 V, 5 mm pitch
C7, C9, C11, C12 = 1 µF, 16 V, 2 mm pitch
C8 = 470 pF, 50 V, 5 mm pitch
C10 = 1 µF, 250 V, 2.5 mm pitch
Inductors
L1 = 470 µH
Semiconductors
D1, D2, D3, D4, D5, D6, D7 = 1N4148
D8 = STPS1150
IC1 = NE555
IC2 = 74HC374
IC3 = MC34063
IC4 = 78L05
T1, T2, T3, T4, T5 = MPSA42
T6 = STQ2LN60K3-AP
Miscellaneous
K1 = PP3 9 V battery holder
NE1, NE2, NE3, NE4, NE5, NE6, NE7, NE8, NE9, NE10, NE11, NE12, NE13 = neon light
S2 = Miniature slide switch
S1 = Pushbutton (12 x 12 mm)
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