S2A has been replaced by s2a_fm. https://github.com/MrYsLab/s2a_fm
A Scratch 2.0 Hardware Extension written in Python
Connect your Scratch creations to an Arduino UNO or Leonardo, without having to write one line of additional code! Three demos are included: 1. The obligatory "Blink the pin 13 LED - Arduino Hello World" (from Scratch of course!) 2. CodeShield - display the data from all sensors and control each actuator from Scratch. 3. A Scratch remix of the Simon memory game, using the Arduino to enter your guesses and to display the colors. A sample breadboard wiring layout is provided.
How is this all done without any additional user coding? Read the included documentation to find out.