Simple ARM example for LPC1114

My Colleagues Frank Duignan and Richard Hayes have been experimenting with an ARM microcontroller in a dual inline package (DIP) which can be plugged straight into a breadboard. The chip they’re using is LPC1114FN28/102, which is made by NXP and available for less than €2. Frank spent a bit of time working out how to program the chip using a low-cost USB-to-serial converter, so the whole thing provides a micrcontroller programming setup that’s incredibly inexpensive, but quite powerful!

Under Frank’s guidance, I’ve just implemented a simple flashing LED example for the ARM LPC1114. The following code is basically a stripped back version of the more complex example he sent me.

//
// main.c - Blinking LED example for ARM LPC1114
// Written by Ted Burke (based on code by Frank Duignan)
// Last updated 29-11-2013
//

#include "lpc111x.h"

int main()
{
    // Turn on clock for GPIO, IOCON and ADC
    SYSAHBCLKCTRL |= BIT6 + BIT13 + BIT16;
    GPIO0DIR = BIT8; // Make PIO0_8 an output
    GPIO0DATA = 0;   // Turn off PIO0 outputs
    
    int n;
    while(1)
    {
        GPIO0DATA = BIT8; // Turn on PIO0_8
        n=1000000; while(--n);
        GPIO0DATA = 0;    // Turn on PIO0_8
        n=1000000; while(--n);
    }    
}

I’m using the following build script (“build.bat”), courtesy of Frank Duignan.

arm-none-eabi-gcc -mcpu=cortex-m0 -mthumb -g -c init.c -o init.o
arm-none-eabi-gcc -mcpu=cortex-m0 -mthumb -g -c main.c -o main.o
arm-none-eabi-ld init.o main.o -L "c:\Program Files\GNU Tools ARM Embedded\4.7 2013q3\lib\gcc\arm-none-eabi\4.7.4\armv6-m" -lgcc -T linker_script.ld --cref -Map main.map -nostartfiles -o main.elf
"C:\Program Files\GNU Tools ARM Embedded\4.7 2013q3\arm-none-eabi\bin\objcopy" -O ihex main.elf main.hex

I used the following ARM version of gcc to build the program:

https://launchpad.net/gcc-arm-embedded/4.7/4.7-2013-q3-update/+download/gcc-arm-none-eabi-4_7-2013q3-20130916-win32.exe

I used Flash Magic to transfer the compiled code (main.hex) to the microcontroller:

http://www.flashmagictool.com/download.html&d=FlashMagic.exe

There are a couple of other bits and pieces that are required to build the program, namely a header file “lpc111x.h”, a linker script “linker_script.ld” and a C file with some init code “init.c”. Frank is planning to post those online over the weekend, so I’ll update this post with links once I have them.