Platforms – PICSimLab

MPLAB X Plugin for PICSimLab: Install the .nbm Plugin and Debug over TCP

Admin — Thu, 22 Oct 2026 03:58:41 +0000

MPLAB X Plugin for PICSimLab: Install the .nbm Plugin and Debug over TCP

PICSimLab has no built-in source code editor — by design, you write and build firmware with the same tools you would use for a real board. For PIC projects that tool is usually MPLAB X, and PICSimLab ships a small plugin that makes MPLAB X treat the simulator like a hardware debug tool. This guide covers installing the plugin, connecting it, and the one network setting that trips people up. It assumes PICSimLab itself is already installed (see the Windows installation guide or the platform pages).

What the plugin does

The plugin file is com-picsim-picsimlab.nbm (27,091 bytes in v0.9.3, SHA-256 72c47991bca337b55bafe83e85d7562a5419115cb8e3446bcce681d260a4fd46). Per the official documentation, once it is installed in MPLAB X it lets MPLAB X debug and program PICSimLab — for PICs and AVRs — much as it would with a real board connected. The plugin connects to PICSimLab through a TCP socket on port 1234 (or another port defined in the configuration window).

Download the plugin here: com-picsim-picsimlab.nbm (official GitHub release file for v0.9.3).

Step 1: Install the .nbm in MPLAB X

Download com-picsim-picsimlab.nbm using the link above.
In MPLAB X, open the Plugins window (Tools → Plugins), go to the Downloaded tab, and choose Add Plugins.
Select the downloaded .nbm file and complete the installation, restarting MPLAB X if it asks.

Step 2: Prepare PICSimLab

Start PICSimLab and load the board and firmware you want to debug.
Open PICSimLab’s configuration for the MPLAB X connection and confirm the port — the default is 1234. If you change it, the MPLAB X side must use the same port.
Leave PICSimLab running while you work in MPLAB X; the plugin connects to the running simulator.

Step 3: Allow the connection through the firewall

The official documentation calls this out explicitly: because the plugin talks to PICSimLab over a TCP socket, you have to allow the access in the firewall. On Windows, if a firewall prompt appears when the connection is first made, allow it for your local network; if no prompt appears and the connection fails, add an allow rule for PICSimLab / port 1234 in your firewall settings. Both programs normally run on the same PC, so this is a localhost connection — you are not exposing the port to the internet, and you should not forward it on your router.

Step 4: Debug from MPLAB X

With the plugin installed and PICSimLab running, select the PICSimLab tool in your MPLAB X project and start a debug session as you would with a hardware tool: MPLAB X connects over TCP, programs the simulated device, and lets you run, halt and inspect your code while PICSimLab shows the board reacting. If the connection is refused, check the three usual causes: PICSimLab is not running, the port numbers differ between the two programs, or the firewall blocked the connection.

Good to know

The same 1234 port also appears in PICSimLab’s GDB workflows for other backends (avr-gdb, arm-gdb, esp32-gdb). The MPLAB X plugin is a separate path for PIC and AVR work inside MPLAB X — do not confuse the two when following a tutorial.
The plugin file is versioned with PICSimLab itself: when you update PICSimLab, download the .nbm from the same release (the link above always points at the v0.9.3 file from our Download page).

Related guides

Virtual Serial Ports for PICSimLab: com0com on Windows and tty0tty on Linux

Admin — Thu, 22 Oct 2026 03:58:34 +0000

Virtual Serial Ports for PICSimLab: com0com on Windows and tty0tty on Linux

Serial communication is where many first PICSimLab projects get stuck — not because the simulator is broken, but because there is a piece of setup the desktop version cannot do for you. This guide explains what that piece is and how to set it up on Windows and Linux. It applies after you have installed PICSimLab itself (see the Windows and Ubuntu & Debian guides, and the platform pages under Download).

Why a virtual port pair is needed

On a real development board, the microcontroller’s UART is wired to a USB-to-serial chip, and your PC sees a COM port (Windows) or a /dev/ttyUSB* device (Linux). PICSimLab’s simulated board has a serial port too — but it exists only inside the simulation. For another program (a serial terminal, the Arduino IDE serial monitor, your own script) to talk to it, the simulated port must be connected to something your operating system can open.

The official PICSimLab documentation states the prerequisite plainly: desktop serial simulation needs a NULL-MODEM virtual serial port pair. A pair is two virtual ports wired back-to-back, like a null-modem cable: PICSimLab opens one end, your terminal program opens the other, and bytes written to one appear at the other. The port format used is 8N1 — 8 data bits, no parity, 1 stop bit — with the baud rate set to whatever your firmware expects.

Note that this is a desktop-version topic: the official online version of PICSimLab has no serial communication support (only the IO Vterm virtual terminal), per the official documentation.

Windows: com0com

Install com0com, the free open-source null-modem emulator for Windows named in the official documentation.
Use its setup utility to create a port pair (for example COM10 and COM11). Keep the pair dedicated to PICSimLab so other programs do not grab the ports.
In PICSimLab, configure the board’s serial port to use one end of the pair (for example COM10).
Open the other end (COM11) in your serial terminal or IDE, set the format to 8N1 and the baud rate your firmware uses, and start the simulation. Text your firmware sends now appears in the terminal, and what you type goes to the simulated board.

Linux: tty0tty

Install tty0tty, the virtual null-modem driver named in the official documentation. It creates linked device pairs such as /dev/tnt2 <=> /dev/tnt3.
Note the pair it creates (the exact numbers depend on your system). Make sure your user account is permitted to read and write those device files; if opening a port fails with a permission error, fix the device permissions or group membership for the tty devices first.
In PICSimLab, point the board’s serial port at one end of the pair (for example /dev/tnt2).
Open the other end (for example /dev/tnt3) in your terminal program, set 8N1 and the firmware’s baud rate, and run the simulation.

Quick checks when nothing arrives

Crossed ends: PICSimLab and the terminal must be on opposite ends of the pair. Two programs on the same end hear nothing.
Settings mismatch: both sides must use 8N1 and the same baud rate as the firmware. Garbled text usually means the baud rate is wrong.
Port busy: only one program can open each end. Close other terminals or IDE monitors that may hold the port.
Simulation running: the firmware only transmits while the simulation is running and the loaded .hex actually uses the UART.

Related guides

How to Install PICSimLab on macOS

Admin — Thu, 22 Oct 2026 03:58:28 +0000

How to Install PICSimLab on macOS

PICSimLab v0.9.3 (released 20 September 2026) is the first release with native macOS builds — before v0.9.3 there was no official macOS package at all. This guide covers downloading the right .dmg for your Mac, installing it, and getting past the standard macOS first-open confirmation. All files and checksums are on our PICSimLab for macOS page and the main Download page.

Step 1: Pick the build for your Mac

There are two .dmg files, and they are not interchangeable:

Apple Silicon (M-series chips): PICSimLab_0.9.3_260920_macOS_26.6.2_arm64.dmg (27,970,234 bytes, SHA-256 46cae7379b3828d771feefcaeb040f87d02ffbd5bd160dcda6152c8fa14b8b00)
Intel Macs: PICSimLab_0.9.3_260920_macOS_26.6.1_x86_64.dmg (28,724,896 bytes, SHA-256 cb6af4651fe811dab3088667f34f3d0495960ec6b0bb4627f44f73a21386d07b)

To check your Mac, open the Apple menu and choose “About This Mac”: an Apple M-series chip means arm64; an Intel processor means x86_64. The version numbers inside the official file names are simply part of the names as published by the project.

Step 2: Download and verify

Download the .dmg from the macOS page — the buttons link to the official GitHub release files. If you want to verify the download, open Terminal in the download folder and compare:

shasum -a 256 PICSimLab_0.9.3_260920_macOS_26.6.2_arm64.dmg

The output must match the SHA-256 for your build in Step 1. Verifying is a good habit in general, and it is the reliable way to know a file is the genuine release.

Step 3: Install

Open the .dmg and drag PICSimLab into your Applications folder, as you would with other Mac apps. Eject the disk image afterwards.

Step 4: First open (Gatekeeper)

The first time you open an app downloaded from the internet, macOS may show a confirmation dialog, or may decline to open the app by double-click because it was downloaded from the web. This is Gatekeeper, the standard macOS check for downloaded apps — it is not specific to PICSimLab. The standard ways through it are:

Right-click (or Control-click) PICSimLab in Applications and choose Open, then confirm in the dialog.
Or, after a blocked attempt, open System Settings → Privacy & Security and use the Open Anyway option for PICSimLab.

Only do this for a file whose checksum you verified in Step 2. After the first successful open, PICSimLab launches normally from Applications.

Step 5: Run your first simulation

Choose a development board (21 are supported, including PIC boards, Arduino Uno and Mega, Blue Pill and the ESP32 boards), load a compiled .hex file, and press run. PICSimLab does not edit or compile source code — write and build your firmware in MPLAB X, the Arduino IDE, or VS Code with PlatformIO, just as for real hardware, then simulate it here. Coming from another platform? The workflow is the same as in our Windows and Ubuntu & Debian guides.

A note on system requirements

The PICSimLab project does not publish official minimum system requirements for macOS (or any platform), so this site does not list any. What the release itself tells you is exactly what is above: separate Intel and Apple Silicon builds, new in v0.9.3.

Related guides

How to Install PICSimLab on Ubuntu and Debian

Admin — Thu, 22 Oct 2026 03:58:21 +0000

How to Install PICSimLab on Ubuntu and Debian

PICSimLab v0.9.3 (released 20 September 2026) gives Linux users three installation routes: a .deb package, a Flatpak, or a portable AppImage. This guide covers all three. All files, sizes and SHA-256 checksums are listed on our PICSimLab for Linux page and the main Download page.

Route 1: The .deb package (Ubuntu)

The project publishes two separate .deb builds — one for Ubuntu 24.04 and one for Ubuntu 22.04. They are not interchangeable, so download the one that matches your release:

Ubuntu 24.04: PICSimLab_0.9.3_260920_Ubuntu_24.04.5_LTS_amd64.deb (11,672,298 bytes, SHA-256 89510e3d917fa9cb19c8dde5b2facdbd0ee4a50422ba3ba487b201c6f2046fa7)
Ubuntu 22.04: PICSimLab_0.9.3_260920_Ubuntu_22.04.5_LTS_amd64.deb (11,754,202 bytes, SHA-256 1862c3e78e99d427b854083d7ce1ab4a3e86023348150bdb695bc381f72921f1)

Verify the file with sha256sum .deb, then install it in a way that resolves dependencies automatically, for example:

sudo apt install ./PICSimLab_0.9.3_260920_Ubuntu_24.04.5_LTS_amd64.deb

After installation, PICSimLab appears in your applications menu. Debian users on a release close to one of the Ubuntu builds can try the matching .deb; if the package does not fit your system, use the Flatpak or AppImage route instead — the simulator itself is identical.

Route 2: Flatpak

Download picsimlab_Linux_0.9.3_260920.flatpak (20,059,656 bytes, SHA-256 0284578615cf130dfb9b0c8aca110bcd140c087db41d0df6e9e135cde9ddf899) from the Linux page and install the bundle:

flatpak install picsimlab_Linux_0.9.3_260920.flatpak

Then launch PICSimLab from your applications menu or via flatpak run. The Flatpak is the comfortable route on distributions that are neither Ubuntu 22.04 nor 24.04.

Route 3: AppImage (no installation)

Download PICSimLab-0.9.3_260920_Ubuntu_22.04.5_LTS_x86_64.AppImage (67,115,512 bytes, SHA-256 fe403bb783fd46cb9d172d5895649b83dd2d2a9e0cd1b6542eb5ebc0ed17b467), make it executable, and run it:

chmod +x PICSimLab-0.9.3_260920_Ubuntu_22.04.5_LTS_x86_64.AppImage ./PICSimLab-0.9.3_260920_Ubuntu_22.04.5_LTS_x86_64.AppImage

Nothing is installed system-wide, which makes the AppImage the easiest route for a quick test or a machine where you cannot install packages.

Headless option: the NOGUI build

The release also includes PICSimLab_NOGUI-0.9.3_260920_Ubuntu_22.04.5_LTS_x86_64.AppImage — a Linux-only build with no graphical interface. Per the official release notes, the NOGUI version must be used on a terminal and with the remote control interface (rcontrol), a text-command TCP interface (default port 5000) that can start and stop simulations, load .hex files and inspect pins. It is meant for scripted and automated runs, not for interactive learning.

First launch and serial ports

Whichever route you took, the workflow inside PICSimLab is the same: choose a development board (21 are supported), load a compiled .hex file, and run. PICSimLab does not edit or compile source code — build your firmware in MPLAB X, the Arduino IDE, or VS Code with PlatformIO, as you would for real hardware.

For serial communication, the desktop version needs a virtual null-modem port pair. On Linux that is provided by tty0tty, which creates linked pairs such as /dev/tnt2 <=> /dev/tnt3; make sure your user account is allowed to read and write those device files. The full serial setup is covered in the virtual serial ports guide linked below. New to PICSimLab on another platform too? See also our Windows installation guide.

Related guides

How to Install PICSimLab on Windows

Admin — Thu, 22 Oct 2026 03:57:27 +0000

How to Install PICSimLab on Windows

This guide walks through installing PICSimLab v0.9.3 (released 20 September 2026) on Windows, from choosing the right file to running your first simulation. If you only want the files, they are all listed — with sizes and SHA-256 checksums — on our PICSimLab for Windows page and the main Download page.

Step 1: Choose the right file

PICSimLab for Windows comes in four files:

win64_setup.exe (59,917,837 bytes) — the standard installer for 64-bit Windows. This is the right choice for almost everyone.
win32_setup.exe (59,629,851 bytes) — the installer for 32-bit Windows.
win64.zip (100,521,245 bytes) and win32.zip (98,077,259 bytes) — portable copies that run without installation.

If you are not sure whether your Windows is 64-bit, it almost certainly is; the 32-bit builds exist for older 32-bit installations.

Step 2: Download and verify

Download the installer from the Windows download page. The buttons there link to the official GitHub release files. To verify the download, open PowerShell in your Downloads folder and run:

Get-FileHash .\PICSimLab_0.9.3_260920_win64_setup.exe

For the 64-bit installer, the SHA-256 must be acb584b83c60e93ae35060d458bb2e2f28e2287683e2de83fff3999357902dc4. Checksums for the other files are in the table on the Windows page.

Step 3: Install (or unzip)

Run the setup file and follow the installer prompts; there are no special options to change. If you downloaded a ZIP instead, extract it to a folder of your choice and run PICSimLab from that folder — nothing is installed and nothing is written outside the folder by the simulator itself.

Step 4: First launch

Start PICSimLab, select a development board (for example one of the PIC boards, an Arduino Uno, Blue Pill or ESP32-DevKitC — 21 boards are supported in total), and load a compiled firmware file (.hex) to run it. You can also open one of the example configurations that ship with the program to see a working simulation immediately.

One thing PICSimLab does not do is edit or compile source code — the official documentation states this plainly. Write and build your firmware in MPLAB X, the Arduino IDE, or VS Code with PlatformIO, exactly as you would for real hardware, then load the resulting .hex (or .elf, where the workflow uses one) into PICSimLab.

Step 5 (optional): Serial port and MPLAB X

Two add-ons are worth knowing about once the basic install works:

Serial communication: the desktop simulator talks to other programs through a virtual null-modem port pair. On Windows that pair is created by the free com0com driver. Without it, the simulated serial port has nothing to connect to.
MPLAB X debugging: the plugin file com-picsim-picsimlab.nbm lets MPLAB X debug and program PICSimLab through a TCP connection, much like a real hardware tool.

Both setups are covered in their own guides, linked below.