This guide walks you through sending emails from an ESP32 using an SMTP server, covering everything from simple HTML and text emails to adding image and .txt file attachments, all done with Arduino IDE and ReadyMail.

Using Arduino Nano and the RYLR999 LoRa module, you can send commands from your smartphone to control electrical appliances over long distances without internet. Bluetooth handles the app connection, while a 16×2 LCD shows communication details.

When Claude Code needs your permission for new commands, it stops and waits quietly, often going unnoticed. This neat project turns an ESP32-based device into a real-time companion that shows when Claude’s stuck and lets you respond with a button press.

Using Arduino UNO R4 WiFi, the PZEM-004T energy meter, and an OLED screen, you can create an IoT smart grid system that monitors voltage, current, power, frequency, and energy consumption and shares data online via ThingSpeak.

A team combined a 2D semiconductor with a photonic crystal to create a device that lets light control other light signals reliably. This breakthrough helps overcome the challenge of weak light interactions in photonic systems, pushing all-optical computing closer.

Using the tiny Digispark ATtiny85 board, you can easily interface an HC SR501 PIR sensor for motion sensing, replacing bulkier Arduino UNO boards and adding features like onboard LED indicators and WS2812B RGB animations.

Instead of using the bulky Bluedroid for Bluetooth on your ESP32, NimBLE provides a slim, open-source BLE stack that cuts down memory use and processing load. Learn why NimBLE beats Bluedroid and how to deploy your first NimBLE BLE server with Arduino.

This custom game controller uses an STM32 chip and NRF24L01 transceiver to deliver smooth analogue controls for racing games, supporting multiple firmware modes like X-INPUT and D-INPUT. It’s low power, has a custom PCB design, and offers wireless ranges of 100m or more with a PA+LNA module upgrade.

ZeroDesk’s design uses locally available parts and standard MIDI over USB to deliver professional DAW (digital audio workstation) control features, letting you play, stop, record, and adjust faders in real time for less than $15.

Romu is a miniature RP2354A microcontroller board designed to fit inside a USB Type-A port, featuring an RGB LED, capacitive touch button, and native USB 2.0 support. It runs MicroPython out of the box and includes debugging pins, making it a versatile tool for embedded projects.

If you’ve struggled with short battery life on your ESP32, it’s because its dual cores and radios can draw over 240mA. Luckily, the ESP32 has four power-saving modes that shut down different parts of the chip, from modem sleep to full hibernation, letting you extend runtime from hours to even decades, all shown with Arduino code and a real-world alert sensor project.

Using the Arduino UNO Q’s STM32 MCU for sensors and its Linux MPU for OpenClaw AI vision, this gadget cross-verifies stove safety and reports results in natural language through Telegram without extra apps.