What am I doing wrong in this brief sketch. I expect the hh integer to end with a value of 15 and instead it remains 3?
Also, is there a better way to convert a 12hr format to 24hr format? Note this is just the problem piece of code.
void setup() {
// put your setup code here, to run once:
Serial.begin(9600); // allow for displaying values
int hh, i = 0; // following code is to convert hours to 24 hr format from 12 hour format
char vp[25] = "03:15:27 PM", hrStg[3], ampm[2];
hrStg[0] = vp[i + 0]; hrStg[1] = vp[i + 1]; hrStg[2] = '\0'; hh = atoi(hrStg);
ampm[0] = vp[i + 9]; ampm[1] = '\0';
if ((ampm == "P" ) && (hh != 12)) {
hh = hh + 12;
itoa(hh, hrStg, 10);
}
Serial.println(vp);
Serial.println(hh); // why is this showing 3 when I think it should be 15
Serial.println(hrStg);
Serial.println(ampm);
Serial.println(i);
}
Welcome to the Forum. Please read this post:
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Please post your code using code tags. The code tags make the code look
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Unless the sketch is too large, it's better if you post your code, rather than attach it. When it's attached, we have to download it, create a folder then open your code in our IDE. And afterwards, the folder remains unless we navigate to the "Temp" folder and manually remove it. It's much easier to just view the code in your post.
Also please put only one statement on each line. It is difficult to read otherwise.
An understanding of what strcmp() does. A 0 return code, false, means the strings match. A + value means that the first string comes before the second string in the dictionary. A - value means that the second string comes first.
OK, PaulS. I see what you saying - more clearly than the references I looked at. Thank you. I made it a !strcmp() and that gave me the answer I was looking for.
aarg #5. I have it in the setup() so that I only do this once.
a general comment: the way C seems to handle character comparisons seems to me to be very counter-intuitive. There should be easy, intuitive character handling and comparing functions - which seem to not exist. Am I missing something?
aarg #11 - I was only comparing for the "P" I set the variable ampm up as follows: ampm[0] = vp[i + 9]; ampm[1] = '\0';
When I try to compile your if statement ** if ((ampm[0] == 'P' ) && (hh != 12)) {**
i get the following: ISO C++ forbids comparison between pointer and integer [-fpermissive]
possibly I didn't copy it correctly or we are using different compilers - I am using Arduino 1.6.7