so tinkercad has circuit designand arduno now, a real arduino is $20, IDE is free, fritzing is free and does all the exact same layout stuff locally, you save your files and keep them forever.

My kids’ table lamps use pseudo-random generator for color cycling of an RGB LED with software-PWM on ATTiny85, with internal clock. Free tools, avr-gcc, built on Linux, programmed with AVR ...