modelMCU

Information

Simplified microcontroller with 8 pins and an ideal internal supply (VOH), made of the programmable core Internal.Boards.McuCore (inherited from the common base Internal.Boards.PartialBoard, also inside the board replicas RPi_Pico and MicroBit_v2), an ideal supply VOH and the on-board LED — see the internal diagram. The GND pin is shown by default; with useGroundPin unchecked ("Electrical" tab) it disappears and the microcontroller is referenced to the simulation ground (0 V), common to every Ground block. The core has one electrical stage per pin (Internal.Boards.PinBridge: push-pull output fed by the supply, switchable pulls, voltage sensing) controlled by PyRuntime, which runs the user's Python script (MicroPython-compatible, machine.Pin/machine.ADC/machine.PWM/time API) in a thread that intercepts sleep(). API reference: Raspberry Pi Pico (RP2040), see requirements.md — not shown on the icon, to stay generic. Each pin GP0-GP7 can be used, as the script chooses, as digital (machine.Pin), analog (machine.ADC, 16-bit reading of the voltage measured by the sensor already present in the bridge) or PWM (machine.PWM, square wave generated continuously on the Modelica side once frequency/duty cycle are set — no round trip with the Python thread at each edge, see requirements.md) — unlike the real Pico, where only some pins are ADC-capable, see the restrictions in requirements.md.

The script can import a helper module (import my_module): by default (addScriptDirToPath), the script's folder is added to the Python search path, and libraryPath can additionally designate a .py file of a shared library (its folder is then added too) — see requirements.md, decision "Import de modules auxiliaires".

File system (simulated flash, "File system" tab): disabled by default (fsEnabled), open() and os then raise OSError. When enabled, each simulation copies the fsSource folder (empty = blank flash) into a new folder of fsWorkspace ("." by default: the simulation folder), named <instance>_<FS name>_<date>_<time>; its full path is shown in the log at the start and at the end of the simulation, and Windows Explorer opens on it at the end (fsOpenExplorer). The script sees it as the root / of the flash: open() and the MicroPython-style os module (listdir, mkdir, remove, rename, stat, statvfs, chdir, getcwd...) are confined to it, and the root as well as /lib are on the import path. The source is never modified: each simulation starts again from the same state and stays deterministic (the timestamp only names the copy, the script does not see it). Program run, as on a board: boot.py from the flash if it exists, then scriptPath instead of main.py (like Thonny on an already booted board), or main.py from the flash if scriptPath is empty. See requirements.md, decision "Système de fichiers".

The electrical parameters (logic levels, output resistances) are grouped in the "Electrical" tab. The supply is ideal and implicit: VOH is the internal rail, i.e. the high level of the outputs and of the pull-ups; the microcontroller is always supplied. For a board with real supply pins and regulator, see RPi_Pico.

The Display0 connector exposes a logical link to an educational display peripheral (machine.Display(0).write(text)): unlike the GPx pins, it is not an electrical connector (Modelica.Electrical.Analog) but a causal logical connector (Interfaces.DisplayLinkOutput, message delivered instantly at the sync point, no serial waveform nor simulated baud rate) — to be connected to the displayLink (Interfaces.DisplayLinkInput) of a Peripherals.Display, an optional component (connect it or not, depending on the circuit). See requirements.md, decision "Périphérique d'affichage pédagogique".

The dot on the icon stands for the on-board LED of the Raspberry Pi Pico (wired to GP25 on the real board). It is handled like a normal pin, with the same electrical stage as GP0-GP7 (core.pin[9]) — only without an external connector: the output of this internal bridge permanently feeds a series resistance (ledResistor) and a real Peripherals.LED (builtinLed) connected to GND, true to the actual wiring of the Pico. It is driven from the script exactly like the 8 GPIO pins (machine.Pin(25, machine.Pin.OUT).on()/.off()); it is not one of the 8 exposed GPIO pins (see the restrictions in requirements.md), so no external circuit can be connected to it. Bright green when on, dark green otherwise — visible while replaying a simulation result with animation in OMEdit (DynamicSelect on builtinLed.mean.y), not on a static rendering.

Parameters

Connectors

Components