[Kevin] attached a MicroSD breakout board to an Arduino-compatible clone. When the clone starts up, it searches the SD card for a file called ‘program.hex.’ This file is sent over to the ...

A Arduino on a SD carrier already exists – or, at least, an Arduino on a Micro SD carrier. The OpenLog device (Sparkfun). An Arduino, with source code for the data logging function, ...

Operating System Linux Arduino IDE version 2.3.2 Board Adafruit Metro RP2040 ArduinoCore version earlephilhower 4.0.1 TinyUSB Library version 3.3.3 Sketch as ATTACHED TXT stock example ...

But it's possible to go even smaller, as the makers of a new Arduino-compatible product called "Microduino" show. At 1" × 1.1", it's nearly as small as a quarter.