modelPartialUsbBoard
Common base of the boards supplied through USB (RPi_Pico, MicroBit_v2): the USB supply parameters are written here once - each board keeps its own supply chain (pins, components, wiring), whose placement and topology are board-specific
Extends from PartialBoard (Common base of the boards (MCU, RPi_Pico, MicroBit_v2): the user settings and the core contract are written here once - the boards add their pins, their connectors, their supply and their pin table (modifier of core in their extends)).
Information
Common base of the USB-supplied boards RPi_Pico and MicroBit_v2, on top of PartialBoard: only the USB supply parameters are shared (usbConnected, VUsb, RUsb, eta), because the supply chains really differ - the Pico exposes VBUS/VSYS as public pins with the Schottky between them, the micro:bit feeds its regulator from the USB rail and exposes 3V only. The conditional components (usbSupply, usbCable) and their wiring stay in each board: their placement cannot be changed by inheritance, and so does the drawn routing of their wires.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.Time | tickPeriod (from PartialMcuSettings) | 0.1 | Period of the minimal sync point (output freshness if the script never sleeps) |
| Python script | |||
| String | scriptPath (from PartialMcuSettings) | Modelica.Utilities.Files.loadResource("modelica://MicroPythonMCU/Resources/Scripts/MCU/demo.py") | Path of the user script (.py) - with an active file system, run after boot.py instead of main.py; empty = main.py from the flash |
| Boolean | addScriptDirToPath (from PartialMcuSettings) | true | Make the .py files next to the script importable (e.g. import my_module) - mimics the real Pico (flash root folder on sys.path) |
| String | libraryPath (from PartialMcuSettings) | "" | Optional: a .py file from a shared library folder to make importable (the folder containing this file is added to the module search path) - leave empty if unused |
| File system › Simulated flash | |||
| Boolean | fsEnabled (from PartialMcuSettings) | false | Enable the file system (simulated flash) - disabled: open() and os raise OSError |
| String | fsSource (from PartialMcuSettings) | "" | Initial image of the flash (folder: data, boot.py, main.py, lib/), copied at each simulation and never modified - any file of the folder, the folder path or a modelica:// URI; empty = blank flash, only the script runs |
| String | fsWorkspace (from PartialMcuSettings) | "." | Workspace: folder where each simulation creates its copy, named <instance>_<FS name>_<date>_<time> (created if missing) - "." or relative path = from the simulation folder; full path of the copy shown in the log |
| Boolean | fsOpenExplorer (from PartialMcuSettings) | true | Open Windows Explorer on the copy at the end of the simulation |
| Execution time | |||
| Modelica.Units.SI.Time | gpioOpTime (from PartialMcuSettings) | 5e-6 | Execution time of a pin access (Pin.value(), on(), off()): two writes without sleep() give a pulse of this width (bit-banging) - order of magnitude of MicroPython on RP2040; 0 = instantaneous accesses |
| Modelica.Units.SI.Time | hangWarningTime (from PartialMcuSettings) | 10 | Real (wall-clock) time after which a warning is logged if the script does not let the simulation advance (loop without sleep() nor pin access, or with gpioOpTime = 0) - the simulation keeps waiting; 0 = no warning |
| Debugging | |||
| Boolean | debugEnabled (from PartialMcuSettings) | false | Debug the program with VS Code: at the start of the simulation, the microcontroller waits until VS Code attaches (debugpy, Run and Debug > attach to localhost:debugPort); simulated time stays frozen while the program is paused - one microcontroller per model |
| Integer | debugPort (from PartialMcuSettings) | 5678 | Local TCP port on which the debugger (debugpy) listens - the port of the VS Code attach configuration |
| Electrical › Logic levels | |||
| Modelica.Units.SI.Voltage | VOL (from PartialMcuSettings) | Interfaces.VOL | Logic low voltage |
| Modelica.Units.SI.Voltage | VIH (from PartialMcuSettings) | Interfaces.VIH | Threshold above which an input reads high |
| Modelica.Units.SI.Voltage | VIL (from PartialMcuSettings) | Interfaces.VIL | Threshold below which an input reads low |
| Electrical › Output stages | |||
| Modelica.Units.SI.Resistance | ROut (from PartialMcuSettings) | Interfaces.ROut | Output series resistance (drive strength) |
| Electrical › Input stages | |||
| Modelica.Units.SI.Resistance | RPullUp (from PartialMcuSettings) | Interfaces.RPull | Internal pull-up resistor to the supply, switched on by Pin(n, mode, Pin.PULL_UP) and by I2C() on SCL/SDA |
| Modelica.Units.SI.Resistance | RPullDown (from PartialMcuSettings) | Interfaces.RPull | Internal pull-down resistor to GND, switched on by Pin(n, mode, Pin.PULL_DOWN) |
| Modelica.Units.SI.Conductance | GOff (from PartialMcuSettings) | Interfaces.GOff | Leakage of a pin that does not drive its line (input, released I2C line), towards GND: 1e-9 S = 1 GOhm |
| Power supply › Consumption | |||
| Modelica.Units.SI.Current | ICore (from PartialBoard) | 0.02 | Current drawn from the supply rail by the core and its memory while supplied (program running, pins excluded) |
| Power supply › Power-on | |||
| Modelica.Units.SI.Voltage | VPowerOn (from PartialBoard) | 1.8 | Supply rail voltage above which the core starts (power-on reset) |
| Modelica.Units.SI.Voltage | VPowerOff (from PartialBoard) | 1.6 | Supply rail voltage below which a running core stops for good (brown-out) |
| Power supply › USB | |||
| Boolean | usbConnected | true | USB cable plugged in: 5 V through the USB connector (the board runs without any wiring) - false to supply the board through its supply pin |
| Modelica.Units.SI.Voltage | VUsb | 5 | Voltage of the USB supply |
| Modelica.Units.SI.Resistance | RUsb | 0.2 | Resistance of the USB cable and connector |
| Power supply › Regulator | |||
| Real | eta | 0.9 | Efficiency of the regulator |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Internal.Boards.PartialMcuCore | core (from PartialBoard) | Programmable core, public like in the boards so that its plotted variables (powerGood, supplyOk...) stay in the simulation results - partial: every board redeclares it (McuCore); pin table (nPins, pinIds, pinCaps), board profile and on-board devices are set by the board in the modifier of its extends, pins in the order of pinIds |