Then, an Arduino board might be exactly what you're looking for. This open-source hardware platform comes in a multitude of versions, from the classic Uno to ... three headers labeled OFF, GND ...

Arduino has launched its next generation of UNO boards, introducing a 32-bit Renesas microcontroller and Espressif ESP32-S3 module, one-click cloud connectivity and plenty of I/O plus a 12×8 red LED ...