[Developing in NXC using XCode]

3. Create program files

Create folders 'build' and 'source' in the project folder and drag them into XCode to create groups. Next, create the main project file in the 'source' folder, naming it 'MyProject.nxc'. This file should contain the main task, i.e. code that will get executed when the program runs. Put the following into the file:

task main() {
    TextOut(0, LCD_LINE2, "Hello world!");
    until(ButtonPressed(BTNEXIT, true));
}
This tells the program to display text until the exit (dark gray) button on the brick is pressed. You should always use the 'until' statement or a while loop unless you want your program to exit as soon as it starts.

4. Create a make file

Create file named 'Makefile' (no extension) in the root of the project directory, i.e. one level up from 'source'. The Makefile will automatically be linked to XCode's Build function. Paste in the following:

# Path to the NXC compiler relative to the Makefile
NXC=/Developer/SDKs/nxt/nbc

# Options to pass to the compiler.
# Use -EF to specify we are using enhanced firmware.
# Use -d to specify we want to download to the brick.
OPTIONS=-Z2 -I=../$(SOURCE)/ -EF -d

# Program settings
SOURCE=source
BUILD=build
PROGRAM=MyProject
############

all: $(PROGRAM).rxe

$(PROGRAM).rxe: $(SOURCE)/$(PROGRAM).nxc Makefile
    cd $(SOURCE); \
    $(NXC) -O=../$(BUILD)/$(TARGET_NAME).rxe \
        $(OPTIONS) \
        $(PROGRAM).nxc

clean:
    /bin/rm -vf $(BUILD)/$(PROGRAM).rxe
The first part of the file defines some constants and you should change them based on your computer setup. The NXC and NXTCOM specify paths to command-line tools you downloaded in Step 1. The SOURCE and BUILD constants specify your folder names and PROGRAM sets the program name, which should be the same as your project and main .nxc file name. Press build (CMD + B) and the program should build and be downloaded onto the NXT brick.

Some system have problems when using spaces in the Makefile. Download the Makefile if it does not work when you paste the code in.

Including C files

You are free to use .h files that contain C code in your project, although you are limited by what the NXC compiler supports. I personally only create the main task in NXC and continue coding in a .h file. For example:

MyProject.nxc

#include "MyProject.h"

task main() {
    runProgram();
}
MyProject.h

void runProgram() {
    TextOut(0, LCD_LINE2, "Hello There!");
    until(ButtonPressed(BTNEXIT, true));
}
Notice that while standard C syntax is used ('void' instead of 'task'), you can still use all NXC functions (e.g. TextOut).

In order to work with included files, the NXC compiler needs to know where to look for them. The includes folder can be specified in the Makefile using the –I option:

OPTIONS=-Z2 -I=../$(SOURCE)/
In this example, all .h files are located in the same 'source' folder as the main .nxc file. See nxc –-help for more compiler options.