How to read and write files in CCS v6

mark wood

I am using Code Composer Version: 6.1.0.00104. I am running code on the CC2650DK.

I created a minimum empty project for CC2650DK and entered this code:

#include <stdio.h>

int main(void)
{

    FILE *fp;

   fp = fopen("testfile.txt", "w+");
    fprintf(fp, "%s %s %s %d", "We", "are", "in", 2015);

    fclose(fp);

}

The code runs without error and the file testfile.txt is created in the project Debug folder. However testfile.txt is empty.

What do I need to do to capture sensor data into a file for analysis? This would be extremely helpful for using tools

such as MATLAB to create algorithms to process sensor data in real time.

0 Gautam Iyer over 10 years ago

Guru 192875 points

Hi Mark,

Try using fwrite function instead of fprintf.

Regards,
Gautam

0 Chester Gillon over 10 years ago

Guru 92251 points

mark wood1 said:
What do I need to do to capture sensor data into a file for analysis?

The stdio functions require heap space to buffer the output.

With a Cortex-M4 device when a new project was created, with the heap size left at the default of zero, an empty testfile.txt was created.

When the heap size was increased to 512 bytes the testfile.txt was then populated with the expected contents.

You may also need to increase the stack size. See Getting C I/O working / Troubleshooting

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