NQC

Not Quite C is a simple language with a C-like syntax that can be used to program LEGO’s RCX programmable brick (from the MindStorms set) that is running firmware either standard LEGO firmware (latest [0332] recommended) or the earlier versions of Dick Swan’s “fast” firmware that were still compatible with NQC.

Usage recommendation matrix:

Scenario	Suggestion
Just getting started with programming?	Graphical environments such as the MindStorms RIS software, VisualNQC, or RoboLab might offer a more suitable starting point.
A C programmer who prefers typing a few lines code over drag-and-drop icon programming ?	NQC might be perfect for you.

About This Project

This BrickBot/nqc repo continues the 3.1r6 codebase as found under the SourceForge project site. For a full list of all updates since that NQC 3.1r6 release, please refer to this project’s Releases page.

For bug reports about this fork of NQC, please file a GitHub Issue for this project.

Resources & Information

• Getting Started
• FAQ
• Platform-Specific Setup
  • Windows
  • Linux/Unix (including Cygwin)
  • Mac
  • WebAssembly
• Documentation
  • NQC User Manual
  • NQC Programmer’s Guide
  • Libraries for NQC
  • NQC and the Scout
• NQC Coding Examples
  • NQC Tutorial
  • Example code that accompanied Dave Baum’s Definitive Guide to LEGO MindStorms, Second Edition
  • Community Examples
    • Bulldozer
    • KickerBot
    • Omni
    • Radar

Getting Started

See NQC on Windows or NQC on Linux for how to download the appropriate compiler (nqc or nqc.exe) and put it where your shell can find it as a command.

On Debian-based systems, check out the nqc package (sudo apt install nqc)!

The IR tower should be connected to your modem port (Mac/Linux) or COM1 (Windows). The IR tower should be set for "near" mode (small triangle). The RCX should also be set for this mode, and firmware must already be downloaded.

Compile and download the test file using the following command line:

nqc -d test.nqc

The test program assumes there's a motor on output A and a touch sensor on input 1. It turns on the motor and waits for the switch to be pressed, then it turns off the motor and plays a sound.

If you are using a USB tower or a different serial port you will need to specify the port either by adding a -Sx option (where x is the name of the port) to the command line or by setting the RCX_PORT environment variable. Refer to Installation on Linux for using USB tower on Linux.

Here are some examples:

USB tower (where supported)

nqc -Susb -d test.nqc

Win32 COM2 port:

set RCX_PORT=COM2

Win32 USB port:

set RCX_PORT=usb

 

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References to Original NQC Project Content:

• Original ReadMe.
• Original FAQ
• Original NQC Web Site