mBlock 3.4.12: The Bridge Between Scratch and Arduino

mBlock 3.4.12 represents a specific, highly stable release of the mBlock 3.x software series. Developed by Makeblock, mBlock is a graphical programming environment based on MIT’s Scratch 2.0. While the software has since evolved into mBlock 4 (Scratch 3.0 based) and mBlock 5 (Python/Scratch 3.0 based), version 3.4.12 remains a significant milestone in the history of STEM education tools.

3. Programming model and semantics

• Visual blocks: imperative, event-driven, and data-flow elements. Block categories include motion, control, sensing, operators, variables, lists, and extensions.
• Event model: start-hat blocks (e.g., “when green flag clicked”, “when button pressed”) spawn independent scripts. Broadcasts trigger other scripts, enabling decoupled coordination.
• Concurrency: multiple scripts run in pseudo-parallel via the interpreter’s cooperative scheduler; long-running or blocking native operations can freeze UI unless implemented to yield.
• Variables and scope: global variables are default; some versions support per-sprite variables. Lists provide simple array semantics but lack complex data structures.
• Timing and real-time interaction: the runtime approximates time with tick/update loops. For precise real-time control (e.g., motor PWM timing, tight sensor loops), the on-device firmware rather than host code is the authoritative runtime.

• set digital pin 13 output as HIGH
• wait 1 secs
• set digital pin 13 output as LOW
• wait 1 secs

At its heart, mBlock 3.4.12 is a customized version of Scratch 2.0. While modern versions (mBlock 5) have moved toward web-based and Python-integrated workflows, 3.4.12 remains beloved for its offline stability and direct hardware manipulation. Key Features of Version 3.4.12