PÚCA DSP is an open-source, Arduino-compatible ESP32 development board for audio and digital signal processing (DSP) applications with expansive audio-processing features. It provides audio inputs, audio outputs, a low-noise microphone array, an integrated test-speaker option, additional memory, battery-charge management, and ESD protection all on a small, breadboard-friendly PCB.
Synthesizers, Installations, Voice UI, and More
PÚCA DSP can be used for a wide range of DSP applications, including but not limited to those in the fields of music, art, creative technology, and adaptive technology. Music-related examples include digital-music synthesis, mobile recording, Bluetooth speakers, wireless line-level directional microphones, and the design of smart musical instruments. Art-related examples include acoustic sensor networks, sound-art installations, and Internet-radio applications. Examples related to creative and adaptive technology include voice user interface (VUI) design and Web audio for the Internet of Sounds.
Compact, Integrated Design
PÚCA DSP was designed for portability. When used with an external 3.7 V rechargeable battery, it can be deployed almost anywhere or integrated into just about any device, instrument, or installation. Its design emerged from months of experimentation with various ESP32 development boards, DAC breakout boards, ADC breakout boards, Microphone breakout boards, and audio-connector breakout boards, and – despite its diminutive size – it manages to provide all of that functionality in a single board. And it dos so without compromising signal quality.
Specifications
Processor & Memory
Espressif ESP32 Pico D4 Processor
32-bit dual core 80 MHz / 160 MHz / 240 MHz
4 MB SPI Flash with 8 MB additional PSRAM (Original Edition)
Wireless 2.4 GHz Wi-Fi 802.11b/g/n
Bluetooth BLE 4.2
3D Antenna
Audio
Wolfson WM8978 Stereo Audio Codec
Audio Line In on 3.5 mm stereo onnector
Audio Headphone / Line Out on 3.5 mm stereo connector
Stereo Aux Line In, Audio Mono Out routed to GPIO Header
2x Knowles SPM0687LR5H-1 MEMS Microphones
ESD protection on all audio inputs and outputs
Support for 8, 11.025, 12, 16, 22.05, 24, 32, 44.1 and 48 kHz sample rates
1 W Speaker Driver, routed to GPIO Header
DAC SNR 98 dB, THD -84 dB (‘A’ weighted @ 48 kHz)
ADC SNR 95 dB, THD -84 dB (‘A’ weighted @ 48 kHz)
Line input impedance: 1 MOhm
Line output impedance: 33 Ohm
Form Factor and Connectivity
Breadboard friendly
70 x 24 mm
11x GPIO pins broken out to 2.54 mm pitch header, with access to both ESP32 ADC channels, JTAG and capacitive touch pins
USB 2.0 over USB Type C connector
Power
3.7/4.2 V Lithium Polymer Rechargeable Battery, USB or external 5 V DC power source
ESP32 and Audio Codec can be placed into low power modes under software control
Battery voltage level detection
ESD protection on USB data bus
Downloads
GitHub
Datasheet
Links
Crowd Supply Campaign (includes FAQs)
Hardware Overview
Programming the Board
The Audio Codec
The ESP32-PICO-Kit fits into a mini breadboard. It is fully functional with the minimum number of discrete components, while it has all the ESP32 pins exposed.
Features
Complete up-to-date documentation is available.
All instructions and commands presented work as described.
Plentiful additional information and hardware documentation are available too.
Applications for the ESP32-PICO-KIT can be developed on Windows, Linux or Mac.
Two cores and a radio
Like the ESP8266 the ESP32 has Wi-Fi but adds Bluetooth. It also has two 32-bit cores inside, making it extremely powerful, and providing all the ports and interfaces that the ESP8266 is lacking.Oversimplifying things, one might say that the ESP8266 is a Wi-Fi controller that provides some I/O, whereas the ESP32 is a full-fledged controller that also has Wi-Fi.
ESP32 peripherals
The ESP32 exposes an ADC & DAC, touch sensor circuitry, an SD/SDIO/MMC host controller, an SDIO/SPI slave controller, an EMAC, PWM to control LEDs and motors, UART, SPI, I²C, I²S, infrared remote controller, and, of course, GPIO.
ESP32-PICO-KIT Development board
The ESP32-PICO-D4 is a System-on-Chip (SoC) integrating an ESP32 chip together with a 4 MB SPI flash memory in a tiny 7 x 7 mm package.
The ESP32-PICO-KIT is a breakout board for this SoC with an onboard USB-to-serial converter for easy programming and debugging.
Besides the board, you'll need a programming toolchain. Complete, up-to-date documentation from Espressif is available on the Read the Docs website.
All instructions and commands presented work as described.Plentiful additional information and hardware documentation are available too.
Applications for the ESP32-PICO-KIT can be developed on Windows, Linux or Mac.
ESP32-S2-Saola-1R is a small-sized ESP32-S2 based development board. Most of the I/O pins are broken out to the pin headers on both sides for easy interfacing. Developers can either connect peripherals with jumper wires or mount ESP32-S2-Saola-1R on a breadboard.ESP32-S2-Saola-1R is equipped with the ESP32-S2-WROVER module, a powerful, generic Wi-Fi MCU module that has a rich set of peripherals. It is an ideal choice for a wide variety of application scenarios relating to Internet of Things (IoT), wearable electronics and smart home. The board a PCB antenna and features a 4 MB external SPI flash and an additional 2 MB SPI Pseudo static RAM (PSRAM).FeaturesMCU
ESP32-S2 embedded, Xtensa® single-core 32-bit LX7 microprocessor, up to 240 MHz
128 KB ROM
320 KB SRAM
16 KB SRAM in RTC
WiFi
802.11 b/g/n
Bit rate: 802.11n up to 150 Mbps
A-MPDU and A-MSDU aggregation
0.4 µs guard interval support
Center frequency range of operating channel: 2412 ~ 2484 MHz
Hardware
Interfaces: GPIO, SPI, LCD, UART, I²C, I²S, Camera interface, IR, pulse counter, LED PWM, TWAI (compatible with ISO 11898-1), USB OTG 1.1, ADC, DAC, touch sensor, temperature sensor
40 MHz crystal oscillator
4 MB SPI flash
Operating voltage/Power supply: 3.0 ~ 3.6 V
Operating temperature range: –40 ~ 85 °C
Dimensions: 18 × 31 × 3.3 mm
Applications
Generic Low-power IoT Sensor Hub
Generic Low-power IoT Data Loggers
Cameras for Video Streaming
Over-the-top (OTT) Devices
USB Devices
Speech Recognition
Image Recognition
Mesh Network
Home Automation
Smart Home Control Panel
Smart Building
Industrial Automation
Smart Agriculture
Audio Applications
Health Care Applications
Wi-Fi-enabled Toys
Wearable Electronics
Retail & Catering Applications
Smart POS Machines
This hardware kit is especially prepared for 'The Official ESP32 Book'. The kit contains all the components used in the projects in this book. With the help of this hardware kit it should be easy and fun to build the projects in the book.
Included
1x ESP32 DevKitC
8x LEDs (RED)
1x LED (GREEN)
2x push-button
8x 330 ohm resistors
1x Buzzer
1x RGB LED
1x TMP36 temperature sensor chip
1x DHT11 temperature and humidity chip
1x MCP23017 (DIL 28 package)
1x LDR
1x BC108 (or any other PNP) transistor
1x 7 segment LED
1x Small Microphone Module
1x I²C LCD
1x SG90 servo
1x 4x4 Keypad
8x Female-Male jumpers
4x Male-Male jumpers
1x Small breadboard
ATOM U is a compact low-power consumption speech recognition IoT development kit. It adopts an ESP32 chipset, equipped with 2 low-power Xtensa 32-bit LX6 microprocessors with the main frequency of up to 240 MHz. Built-in USB-A interface, IR emitter, programmable RGB LED. Plug-and-play, easy to upload and download programs. Integrated Wi-Fi and digital microphone SPM1423 (I2S) for the clear sound record. suitable for HMI, Speech-to-Text (STT). Low-code development ATOM U supports UIFlow graphical programming platform, scripting-free, cloud push; Fully compatible with Arduino, MicroPython, ESP32-IDF, and other mainstream development platforms, to quickly build various applications. High integration ATOM U contains a USB-A port for programming/power supply, IR emitter, programmable RGB LED x1, button x1; Finely tuned RF circuit, providing stable and reliable wireless communication. Strong expandability ATOM U is easy access to M5Stack's hardware and software system. Features ESP32-PICO-D4 (2.4GHz Wi-Fi dual mode) Integrated programmable RGB LED and button Compact design Built-in IR emitter Expandable pinout and GROVE port Development platform: UIFlow MicroPython Arduino Specifications ESP32-PICO-D4 240MHz dual core, 600 DMIPS, 520KB SRAM, 2.4G Wi-Fi Microphone SPM1423 Microphone sensitivity 94 dB SPL@1 KHz Typical value: -22 dBFS Microphone signal-to-noise ratio 94 dB SPL@1 KHz, A-weighted Typical value: 61.4 dB Standby working current 40.4 mA Support input sound frequency 100 Hz ~ 10 KHz Support PDM clock frequency 1.0 ~ 3.25 MHz Weight 8.4 g Product size 52 x 20 x 10 mm Downloads Documentation
The Arduino Nano ESP32 (with and without headers) is a Nano form factor board based on the ESP32-S3 (embedded in the NORA-W106-10B from u-blox). This is the first Arduino board to be based fully on an ESP32, and features Wi-Fi, Bluetooth LE, debugging via native USB in the Arduino IDE as well as low power.
The Nano ESP32 is compatible with the Arduino IoT Cloud, and has support for MicroPython. It is an ideal board for getting started with IoT development.
Features
Tiny footprint: Designed with the well-known Nano form factor in mind, this board's compact size makes it perfect for embedding in standalone projects.
Wi-Fi and Bluetooth: Harness the power of the ESP32-S3 microcontroller, well-known in the IoT realm, with full Arduino support for wireless and Bluetooth connectivity.
Arduino and MicroPython support: Seamlessly switch between Arduino and MicroPython programming with a few simple steps.
Arduino IoT Cloud compatible: Quickly and easily create IoT projects with just a few lines of code. The setup takes care of security, allowing you to monitor and control your project from anywhere using the Arduino IoT Cloud app.
HID support: Simulate human interface devices, such as keyboards or mice, over USB, opening up new possibilities for interacting with your computer.
Specifications
Microcontroller
u-blox NORA-W106 (ESP32-S3)
USB connector
USB-C
Pins
Built-in LED pins
13
Built-in RGB LED pins
14-16
Digital I/O pins
14
Analog input pins
8
PWM pins
5
External interrupts
All digital pins
Connectivity
Wi-Fi
u-blox NORA-W106 (ESP32-S3)
Bluetooth
u-blox NORA-W106 (ESP32-S3)
Communication
UART
2x
I²C
1x, A4 (SDA), A5 (SCL)
SPI
D11 (COPI), D12 (CIPO), D13 (SCK). Use any GPIO for Chip Select (CS)
Power
I/O Voltage
3.3 V
Input voltage (nominal)
6-21 V
Source Current per I/O pin
40 mA
Sink Current per I/O pin
28 mA
Clock speed
Processor
Up to 240 MHz
Memory
ROM
384 kB
SRAM
512 kB
External Flash
128 Mbit (16 MB)
Dimensions
18 x 45 mm
Downloads
Datasheet
Schematics
This DIY Color Display Kit is a fun and educational project for makers of all ages. It is a great way to learn about electronics, programming, and improve your soldering skills.
Microcontroller
As this kit ships with the ePulse Feather ESP32 development board, the kit thereby inherits all the great features of said devkit.
Display
The large 3.5" 320x480 color display also sports a high-precision capacitive touch interface. Contrary to resistive touch interfaces that often work best when using a stylus this auto-calibrated module offers a smartphone-like user experience.
Connector PCB
The connectors for the display are already pre-assembled on the connector PCB, as those require a more experienced hand at the soldering iron. Hence, for the inexperienced solderer this offers the best of both worlds. Also, you may choose to not add the on-off switch or the Grove connector; both are optional.
The connector PCB offers extendability in two ways: the broken out pins of the microcontroller and the connector for the Grove system.
Specifications
Microcontroller
ESP32
Module
ePulse Feather
Display Resolution
320 x 480
Display Driver
ILI9488
Touch Display
Capacitive
Included
1x ePulse Feather, low-power ESP32 development board
1x 3.5" 320x480 Color Display (ILI9488, TFT) with capacitive touch Interface (FT6236) Color Kit Grande Connector Board
1x Custom connector PCB to connect the ESP32 and the display Header Pins
1x Set of special pin headers (to be soldered to connector PCB Color Kit Power Switch)
1x On-off switch (to be optionally soldered to connector PCB SMD Grove Connector)
1x Grove connector (to be optionally soldered to connector PCB Color Kit Grande Foam Stickers)
4x Double-sided foam adhesive to secured display to PCB
Downloads
Schematics
Documentation
The ESP32-WROOM-32, measuring 25.2 x 18 mm only, contains the ESP32 SoC, flash memory, precision discrete components, and PCB antenna to provide outstanding RF performance in space-constrained applications.
ESP32-WROOM-32 is a powerful, generic Wi-Fi + BT + BLE MCU module that targets a wide variety of applications, ranging from low-power sensor networks to the most demanding tasks, such as voice encoding, music streaming and MP3 decoding.
At the core of this module is the ESP32-D0WDQ6 chip. The chip embedded is designed to be scalable and adaptive. There are two CPU cores that can be individually controlled, and the clock frequency is adjustable from 80 MHz to 240 MHz. The user may also power off the CPU and make use of the low-power co-processor to monitor the peripherals for changes or crossing of thresholds constantly. ESP32 integrates a rich set of peripherals, ranging from capacitive touch sensors, Hall sensors, SD card interface, Ethernet, high-speed SPI, UART, I²S and I²C.
The integration of Bluetooth, Bluetooth LE and Wi-Fi ensures that a wide range of applications can be targeted and that the module is future proof. Using Wi-Fi allows a vast physical range and direct connection to the internet through a Wi-Fi router while using Bluetooth allows the user to conveniently connect to the phone or broadcast low energy beacons for its detection.
The sleep current of the ESP32 chip is less than 5 µA, making it suitable for battery powered and wearable electronics applications. ESP32 supports a data rate of up to 150 Mbps, and 20.5 dBm output power at the antenna to ensure the broadest physical range. As such the chip does offer industry-leading specifications and the best performance for electronic integration, range, power consumption, and connectivity.
Downloads
Datasheet
At the core of this module is ESP32-S2, an Xtensa® 32-bit LX7 CPU that operates at up to 240 MHz. The chip has a low-power co-processor that can be used instead of the CPU to save power while performing tasks that do not require much computing power, such as monitoring of peripherals. ESP32-S2 integrates a rich set of peripherals, ranging from SPI, I²S, UART, I²C, LED PWM, TWAITM, LCD, Camera interface, ADC, DAC, touch sensor, temperature sensor, as well as up to 43 GPIOs. It also includes a full-speed USB On-The-Go (OTG) interface to enable USB communication.FeaturesMCU
ESP32-S2 embedded, Xtensa® single-core 32-bit LX7 microprocessor, up to 240 MHz
128 KB ROM
320 KB SRAM
16 KB SRAM in RTC
WiFi
802.11 b/g/n
Bit rate: 802.11n up to 150 Mbps
A-MPDU and A-MSDU aggregation
0.4 µs guard interval support
Center frequency range of operating channel: 2412 ~ 2484 MHz
Hardware
Interfaces: GPIO, SPI, LCD, UART, I²C, I²S, Camera interface, IR, pulse counter, LED PWM, TWAI (compatible with ISO 11898-1), USB OTG 1.1, ADC, DAC, touch sensor, temperature sensor
40 MHz crystal oscillator
4 MB SPI flash
Operating voltage/Power supply: 3.0 ~ 3.6 V
Operating temperature range: –40 ~ 85 °C
Dimensions: 18 × 31 × 3.3 mm
Applications
Generic Low-power IoT Sensor Hub
Generic Low-power IoT Data Loggers
Cameras for Video Streaming
Over-the-top (OTT) Devices
USB Devices
Speech Recognition
Image Recognition
Mesh Network
Home Automation
Smart Home Control Panel
Smart Building
Industrial Automation
Smart Agriculture
Audio Applications
Health Care Applications
Wi-Fi-enabled Toys
Wearable Electronics
Retail & Catering Applications
Smart POS Machines
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
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.
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.
Introducing the Elecrow ESP32 Terminal, a revolutionary handheld device engineered to elevate your projects to new heights. Boasting a 3.5″ 480 × 320 TFT capacitive...