Welcome to the latest edition of the VoltJots newsletter, linking you to the very best electronics and IoT news, products, and projects.

Hope you enjoy! Until next week,

VoltJots

Using the ESP32 CYD board, you can wirelessly control GPIO pins on two ESP32 boards via ESP-NOW. The CYD sends data to each board’s MAC address, letting you toggle two GPIOs per board through a simple interface with tabs and switches.

Using only two wires, I2C enables short-distance communication between several controllers and peripherals like OLEDs or sensor arrays. It’s a half-duplex protocol where data flows one way at a time, supporting easy expansion by adding or removing devices on the same bus.

Build a real-time air quality monitor by hooking up the DFRobot PM2.5 sensor to the powerful Arduino GIGA R1 WiFi board, featuring dual-core processing and extensive connectivity. The sensor’s laser scattering technology measures particle sizes from 0.3 µm to 10 µm, outputting detailed PM1.0, PM2.5, and PM10 data through a simple I2C interface.

This guide shows how to hook up a rotary encoder to the ESP32 and read its movements, breaking down both the hardware wiring and software methods like interrupts and polling.

By combining two NE612 mixer ICs in a superheterodyne setup, this SDR receiver handles signals from 0.1 to 30 MHz and shifts most radio functions to software, achieving versatile reception of AM, SSB, FM, and DRM with a simple hardware design.

Using a 4.0" display and ESP32, this gadget turns π’s never-ending digits into real-time animated art that changes with each number. You can touch to switch styles, speed up animations, and store your favourite patterns.

Featuring a 4GB Raspberry Pi Compute Module 5, this tablet uses a Waveshare 10-inch touch display and an onboard lithium battery for mobile use. The system boots quickly from an NVMe SSD, with added Wi-Fi and Bluetooth range thanks to an external antenna, all housed in a custom Fusion 360-designed enclosure.

Powered by the RP2040 microcontroller, the ChronoWatch X2040 features a round touchscreen display housed in a custom 3D-printed case. It includes various watch faces, a full settings menu for time, brightness, and screen rotation, and all controls run directly on the watch’s touch interface.

Using a centre-tap transformer, this full-wave rectifier design doubles the effective AC waveform for rectification, resulting in higher DC output and better efficiency than half-wave types, making it vital for powering electronics from AC sources.

Learn how to create ten solar energy projects, from automatic lights to IoT monitoring systems, all focused on harvesting and using solar energy effectively.

The M5Stack Capsule v1.1 packs an ESP32-S3 microcontroller, IMU sensor, MEMS microphone, and IR transmitter into a small battery-powered device with microSD support, buttons, buzzer, RTC, and expansion ports. It upgrades the previous model with better antenna design and lower power use, and works with UIFlow2, Arduino IDE, ESP-IDF, and PlatformIO.

Using an ultrasonic sensor, this project detects nearby objects while parking, displays the distance on a small LCD, and signals danger by shifting LED colours and increasing buzzer beeps as you approach.

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