Open a .sim1 file online: your SimulIDE circuit in the browser
Drop a .sim1 file (or an older .simu) and the SimulIDE circuit opens in the browser as a Mokxi project.
Drop it here, or paste it
The Arduino, the 74xx chips, the LED bars, displays and probes where they stood, every connector and tunnel joined. Put the sketch (.ino) in the same folder or zip and the board runs it, since SimulIDE keeps only a compiled .hex.
An Arduino Uno clocking a 74HC595 into a green LED bar through a resistor array, with a logic probe, a scope, BCD and six-digit displays, a three-input NAND into a 7490, an I2C LCD and a keypad. It opens with the chips powered, the PIC16F84 in the corner as a note, and the report asking for the .ino, since only the .hex path is in the file.
Paste from ChatGPT or ClaudeCopy a prompt, say what to build, paste the answer.
- 1Copy the promptIt teaches your AI how to write a Mokxi project.
- 2Say what to buildPaste the prompt into ChatGPT, Claude, Gemini or Cursor and add what you want, like "a night light with a light sensor".
- 3Paste its answer hereThe whole reply is fine. It opens wired and ready to run.
Only have a photo or a screenshot of the circuit? Give your AI the picture with this prompt instead.
Your AI app supports MCP? Add the Mokxi server and it builds the link for you. How
From Tinkercad? Three stepsBring a circuit across wired, with its code.
- 1Export the circuitIn Tinkercad, open the circuit, press Export and download the .brd file. It has every part and wire.
- 2Download the codeOpen Code, switch to Text and press the download button for the .ino.
- 3Drop both hereChoose or drop the .brd and the .ino together: it opens wired, with the code on the board. No .brd? Paste the Component List with the code under it.
What Mokxi reads from SimulIDE
A .sim1 circuit, the file SimulIDE 1.0 and later save.
A .simu from SimulIDE 0.4 and earlier, which names items with id and places them with x and y where 1.x writes CircId and Pos; both spellings are read.
The circuit XML pasted into the box, as long as it begins with the <circuit> tag and holds <item itemtype=...> lines.
A folder or zip holding the .sim1 and the .ino beside it. The sketch is needed because the circuit file names only the compiled .hex.
What comes across
Every component, where it stood
Each <item> is placed at its Pos, scaled from SimulIDE's 8 pixel grid to Mokxi's 20 unit one, and turned by its rotation. Resistors, capacitors, inductors, LEDs, diodes and zeners, pots, LDRs, thermistors, fixed voltages, rails, batteries, BJTs, MOSFETs, op-amps, the LM555, buttons and switches, DC motors, servos, the DHT22, the HC-SR04, the HD44780 LCD, seven-segment displays, two-input gates, clocks, probes, meters, the scope, the logic analyzer, and the Nokia 5110, SSD1306 and ILI9341 displays each have a Mokxi part.
Boards and chips, pin by pin
An Arduino Uno, Nano, Mega or Leonardo subcircuit is recognized by its label and its pins by name (D13, A0, 5V). A bare ATmega328, 168, 88 or 8 comes in as an Uno, with a note that PB5 is pin 13; an ATtiny25, 45 or 85 is the ATtiny85. 74HC and CD4000 chips are matched leg by leg against SimulIDE's own package files, so a counter whose outputs SimulIDE numbers from Q0 lands on the right legs of Mokxi's chip, and a chip from the circuit's own subcircuit file is matched by pin name instead.
Connectors, nodes and tunnels
Every Connector joins the two pins it names, a Node is a junction, and two Tunnels with the same Name are one connection. A connector drawn straight between two component pins stays a single wire between those pins.
Power that SimulIDE never drew
SimulIDE powers chips, displays and meters without wires and reads an unwired logic input as low. Mokxi's parts behave like real ones, so the import adds a 5 V supply and a ground, wires each chip's VCC and GND to them, ties unwired inputs low (a 74HC595's OE, a 7490's resets), and puts a meter's or scope's ground clip on the circuit ground. The report says the supply and ground were added.
Composite items, as the parts they are made of
A ResistorDip comes in as one resistor per element, a three-input gate as a chain of two gates, a six-digit display as two four-digit ones sharing their segment lines, a four-channel Oscope as two Mokxi scopes, a KeyPad as its buttons, a grounded LedBar as a bar with its cathodes on ground. TextComponent labels become sticky notes.
What does not, and what happens instead
The firmware
SimulIDE loads a compiled .hex from a path written in the file (Program="shift_bar.ino.hex") and keeps the source in its own editor. Mokxi builds from source, so when no .ino is in the upload the report says the board loads firmware from that path, a compiled file Mokxi cannot run, and asks for the sketch it was built from.
Other microcontrollers
A PIC, or any MCU Mokxi does not have, becomes a pink note listing each wired pin and what it was joined to, so the connections can be redone on a board Mokxi has. A pin elsewhere whose only other connection was that chip is named in the report as skipped.
Drawing and window items
Rectangles, ellipses, lines, images and packages are drawing, not circuit, and are dropped without a note. Bus, Node and Tunnel items are joins rather than parts. The Plotter and SerialPort windows that version 0.4 saved as items are dropped as well.
The serial terminal
A SerialTerm is left out along with its wires to the board, with a single note: Mokxi's Serial Monitor is always under the editor and shows what the board prints.
From SimulIDE to Mokxi
Step 1
In SimulIDE, save the circuit. Version 1.0 and later write a .sim1; older versions write a .simu.
Step 2
Put the sketch the board runs (the .ino) in the same folder as the circuit file, or zip the two together. The .hex alone cannot be run here.
Step 3
Drop the folder, zip or file on the box above or on the canvas of the editor, or paste the XML; while it is read, the hint says "Looks like a SimulIDE circuit".
Step 4
Once it opens, the parts are placed and powered, and the summary chip says what was split, what was added and what was left out. Tidy wires (T) routes the connectors around the parts.
Questions about importing from SimulIDE
How do I open a .sim1 file without SimulIDE?
Drop it on this page. The .sim1 is XML with one item per line, and Mokxi reads it directly: each component is placed, each connector joined, and the result opens in the editor. Put the .ino next to it if you want the board to run as well.
Is there a SimulIDE online version?
SimulIDE itself runs on the desktop, on Windows, Linux and macOS. Mokxi is a simulator that runs in a browser tab and reads SimulIDE's files, so the circuit you drew there can be opened and run online without installing anything. The two are compared on their own page, linked below.
Does my Arduino code come across with the circuit?
Not from the circuit file alone. SimulIDE stores only a path to the compiled .hex, and Mokxi compiles C++ from source, so the report asks for the .ino when it finds just the .hex path. Drop the sketch with the circuit, or paste it into the editor afterwards.
Why does the import add a power supply and a ground?
Because SimulIDE powers chips, displays and meters invisibly and treats an unwired logic input as low, while Mokxi's parts need real connections. The import wires every chip's VCC and GND to an added 5 V supply and ground and ties the unwired inputs low, so the circuit behaves as it did in SimulIDE.
What happens to a PIC in my circuit?
It becomes a pink note where it stood, listing its wired pins and what each was connected to. Mokxi has no PIC, so pick an Arduino or another board it has and redo those connections from the list.
Is Mokxi a SimulIDE alternative that runs Arduino code?
For the Arduino, ESP32 and other boards Mokxi has, yes: the sketch is compiled in the browser and runs against the circuit. This page is about the import; the comparison page below weighs the two tools against each other.
Where to next
What this page says about SimulIDE was checked in November 2026 against SimulIDE.
