Linux development environment for TI LaunchPad

The MSP430 LaunchPad development kit from Texas Instruments is very interesting. It includes a development board, two DIP micro controllers, a Mini USB cable, four headers connectors, a crystal and two stickers. But the most exciting part is that you get all this for $4.30 from TI.

I’ve also been using the LaunchPad to program the MCU in the Mini Mood Light v1 which also uses a MSP420G2211.

To get the LaunchPad working with Linux you need a suitable toolchain (assembler, compiler, library and debugger) and flash programing software. Unfortunately the required software isn’t packaged with current Linux distributions, so we need to compile the software ourselves.

In the past it was a complex task setting up a cross compiler. Having to download individual source archives, finding required patches, providing suitable command line options and all that in a specific order. Today we have the MSPGCC4 project which provides and maintains an interactive script which preforms most of the heavy lifting required. We can also use the MSPDebug tool to program and debug the flash on the LaunchPad.

My preferred distribution is Debian but I hope my description is significantly generic to be useful to other distribution users.

The first step is to install as root the required programs, libraries and dependencies which are required to compile the toolchain. On Debian the following command can be used to install the required packages.

# apt-get --no-install-recommends install bzip2 dialog gcc gcc-4.4 \
gzip libc6-dev libncurses5-dev libreadline6-dev libusb-dev \
make patch tar texinfo wget zlib1g-dev

If you want to use the graphical interface to gdb call Insight, also install the X windows libraries. The libx11-dev package on Debian.

My preference is to install and run toolchains inside a sub directory of my home directory, which also allows for easier backups and upgrades in the future.

~$ cd ~
~$ mkdir msp430
~$ cd msp430
~/msp430$ wget http://downloads.sourceforge.net/project/mspgcc4/mspgcc4/mspgcc4-20101114.tar.bz2
~/msp430$ tar jxf mspgcc4-20101114.tar.bz2
~/msp430$ cd mspgcc4-20101114
~/msp430/mspgcc4-20101114$ perl buildgcc.pl

We now need to answer some questions about what versions of tools we will include in our toolchain.

Select GCC version to build: gcc-4.4.5
Select GDB version to build: gdb-7.1
Select Insight version to build: none
Select libc version to build: ti_20101114
Strip debug information from executables after install? Yes
Enter target toolchain path [HOME]/msp430/toolchain (Replace [HOME] with the full path of your home directory i.e. /home/robert)
Create binary package after build? No
Do you want to start build right now? Yes

The build script will now download, configure and compile the required source packages which might take some time depending on the speed of you internet connection and computer.

Once the script as finish you can save some space by deleting the build directory.

~/msp430/mspgcc4-20101114$ rm -rf build
~/msp430/mspgcc4-20101114$ cd ..

Now we’ll install the flash programmer.

~/msp430$ wget http://downloads.sourceforge.net/project/mspdebug/mspdebug-0.13.tar.gz
~/msp430$ tar zxf mspdebug-0.13.tar.gz
~/msp430$ cd mspdebug-0.13
~/msp430/mspdebug-0.13$ make PREFIX=[HOME]/msp430/toolchain all install
~/msp430/mspdebug-0.13$ cd ..

So that we can compile code for the LaunchPad we’ll add the toolchain executables to our path.

~/msp430$ export PATH=$PATH:[HOME]/msp430/toolchain/bin

We can make the toolchain permanently accessible by adding the above export command to our ~/.bashrc startup file.

To test our new toolchain we’ll compile a very simple example program which just blinks the red and green LEDs on the LaunchPad. Save the following as blink.c.

#include "msp430g2231.h"
#include "signal.h"

void main(void) {
        WDTCTL = (WDTPW | WDTHOLD);  // Disable Watchdog timer+

        P1SEL = (0x00);              // Port 1 Select GPIO
        P1DIR |= (BIT6 | BIT0);      // Direction 1.[60] Output
        P1OUT |= (BIT6);

        TACCTL0 = (CCIE);            // Enable interrupt on compare match
        TACCR0 = (0xFFFF);           // Compare value
        TACTL = (TASSEL_2 | MC_1);   // Sub system clock source | Up mode

        _BIS_SR(GIE | CPUOFF);       // General interrupt enable | Turn off CPU
}

interrupt(TIMERA0_VECTOR) TIMER_A0(void) {
        P1OUT ^= (BIT6 | BIT0);
}

To compile the code you can use the following command.

~/msp430$ msp430-gcc -g -mmcu=msp430x2231 -o blink.elf blink.c

To flash the MCU we can use the following command as root.

# [HOME]/msp430/toolchain/bin/mspdebug rf2500 "prog [HOME]/msp430/blink.elf"

If the programming is successful the red and green LEDs should now rapidly turn on and off.