Compiler/MSP-EXP432P401R: MSP-EXP432P401R

Jahleel Fleetwood

Part Number: MSP-EXP432P401R

Tool/software: TI C/C++ Compiler

Recently I have purchased the MSP-EXP432P401R (Red Board). I am attempting to code a program that enables random variables. I have one semester of experience using the MSP-432 which wasn't very helpful in the since that the labs weren't too rigorous. I simply want to have random variables to mimic the rapid change of human glucose. This is some code I have started off the top of the head, as I cannot find any examples of coding using this board. Just need a lemon, and i assure you I can make the lemonade!

* main.c
*/

int x_arr[10]={74,120,60,180,300,250,170,190,55,100,175,245,145}; //an array of random values of gluclose
int main(void)

{
for(i=1; i<14; i++) //for loop chooses value at random from initial array

{
output=x_arr[i]; //outputs values in array

WDT_A->CTL = WDT_A_CTL_PW | WDT_A_CTL_HOLD; // stop watchdog timer
}

over 8 years ago

0 Keith Barkley over 8 years ago

Guru 42215 points

You don't have matching braces {} It should look like this:

main()
{
for()
{
} // end for
} //end main

You only need to stop the watchdog once right after main.

You set aside an array to hold 10 elements, but you stuff it with 13.

Arrays in C are zero based, this ain't no stinking MATLAB!

The correct for idiom to step through an array of 13 elements is:

for(i=0; i<13; i++)
{}

0 Evan W over 8 years ago in reply to Keith Barkley

TI__Mastermind 40600 points

Jahleel,

As far as Keith's answer, his is accurate. As far as code examples, please go here: dev.ti.com/.../

You would likely benefit from DriverLib or Register Level examples as you don't seem to be wanting to use an RTOS.

0 Jahleel Fleetwood over 8 years ago in reply to Keith Barkley

Prodigy 60 points

Thanks , so....

int main(void)
WDT_A->CTL = WDT_A_CTL_PW | WDT_A_CTL_HOLD;//stop watchdog

int x_arr[10]={74,120,60,180,300,250,170,190,55,100,175,245,145}; //an array of random values of gluclose

{
for(i=0; i<13; i++) //for loop chooses value at random from initial array

{
output=x_arr[i]; //outputs values in array
}//end for loop
}//end main

I have this code now the error is #176-D which states expression has no effect. This is line 13 the highlighted line as shown above. I'm assuming none of my values are being read before the for loop?

0 Evan W over 8 years ago in reply to Jahleel Fleetwood

TI__Mastermind 40600 points

Jahleel, your array int x_arr[10], you've defined to have 10 variables stored in it. However, you try to assign 13 variables.

0 Jahleel Fleetwood over 8 years ago in reply to Evan W

Prodigy 60 points

Evan this did no resolve my issue as the variables still have no affect on my code i.e the error message "../main.c", line 14: warning #176-D: expression has no effect" appearing 14 times.

0 Evan W over 8 years ago in reply to Jahleel Fleetwood

TI__Mastermind 40600 points

Jahleel,

I'm not really sure if you have anything else around your code that you're providing, but you've not intialized the variables i and output either. You were also missing an open bracket on main.

Please see the attached code.

#include "msp.h"


/**
 * main.c
 */
int main(void){

    WDT_A->CTL = WDT_A_CTL_PW | WDT_A_CTL_HOLD;//stop watchdog

    int x_arr[13]={74,120,60,180,300,250,170,190,55,100,175,245,145}; //an array of random values of gluclose
    int output[13];
    int i;

    for(i=0; i<13; i++) //for loop chooses value at random from initial array
    {
        output[i]=x_arr[i]; //outputs values in array
    }//end for loop
}//end main

This code receives no errors, only one warning and the warning is because output is never used. I'm going to close this post for now as I believe this is resolved.

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Compiler/MSP-EXP432P401R: MSP-EXP432P401R