Passing elements of time.h's struct tm to a client.println() statement [SOLVED]

Using Arduino Programming Questions
1

I am wanting to printout the current processor time on a webpage that shows other queried data from the ESP32 processor. The issue is
I cannot define the integers hour, min, and sec outside the void printLocalTime() without generating a compiler error. But I need to reference those integers in a manner similar to:

StackString<50> LString = StackString<50>(" Current Pump Cycle [minutes] =  ");
LString.append(current_pump_cycle_min);
client.println(LString.c_str());

void printLocalTime() {    // this function monitors current time of day to initiate 
                           // pump counter reset at midnight
  struct tm timeinfo;
  if (!getLocalTime(&timeinfo)) {
    Serial.println("Failed to obtain time");
    return;
  }
  // Serial.println(&timeinfo, "%A, %B %d %Y %H:%M:%S zone %Z %z ");

  int hour = timeinfo.tm_hour;   
  int min  = timeinfo.tm_min;    
  int sec  = timeinfo.tm_sec;   
  
  if (hour == hour_trigger && min == min_trigger && sec == sec_trigger) {
    Serial.println("Reset counters...");
    counter_reset = true;
    delay(1000);    
  }

If there is a much more efficient straightforward way to add a processor's current time to a webpage I am all ears.
thanks...

2

Did the code you posted generate the error? If so, please post the complete compiler error listing. If not, post that and also the code that does.

3

Ok, I moved the integer definitions hour, min, sec out of void printLocalTime() and placed them in my constants.h file. After reading the entire error message I realized I had used "hour" in a previous declaration so I changed integers descriptors to time_hour, time_min, & time_sec to avoid that conflict. But I am still getting an error about 'timeinfo' was not declared in this scope:

WARNING: library StackString claims to run on avr architecture(s) and may be incompatible with your current board which runs on esp32 architecture(s).
In file included from C:\Users\Ed\IDE 2.0 Sketches-Libraries\Pump_House_Monitor_ver8L\Pump_House_Monitor_ver8L.ino:19:
C:\Users\Ed\IDE 2.0 Sketches-Libraries\Pump_House_Monitor_ver8L\constants.h:61:17: error: 'timeinfo' was not declared in this scope
 boolean counter_reset = false;
                 ^~~~~~~~
C:\Users\Ed\IDE 2.0 Sketches-Libraries\Pump_House_Monitor_ver8L\constants.h:61:17: note: suggested alternative: 'time'
 boolean counter_reset = false;
                 ^~~~~~~~
                 time
C:\Users\Ed\IDE 2.0 Sketches-Libraries\Pump_House_Monitor_ver8L\constants.h:62:17: error: 'timeinfo' was not declared in this scope
 
                 ^       
C:\Users\Ed\IDE 2.0 Sketches-Libraries\Pump_House_Monitor_ver8L\constants.h:62:17: note: suggested alternative: 'time_min'
 
                 ^       
                 time_min
C:\Users\Ed\IDE 2.0 Sketches-Libraries\Pump_House_Monitor_ver8L\constants.h:63:17: error: 'timeinfo' was not declared in this scope
 boolean bldg_alm_ON = false;
                 ^~~~~~~~
C:\Users\Ed\IDE 2.0 Sketches-Libraries\Pump_House_Monitor_ver8L\constants.h:63:17: note: suggested alternative: 'time_sec'
 boolean bldg_alm_ON = false;
                 ^~~~~~~~
                 time_sec
Multiple libraries were found for "WiFi.h"
  Used: C:\Users\Ed\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.9\libraries\WiFi
  Not used: C:\Users\Ed\IDE 2.0 Sketches-Libraries\libraries\WiFiNINA
exit status 1

Compilation error: 'timeinfo' was not declared in this scope

added constants.h segment containing timeinfo :

int hour_trigger = 23;        // hour to reset pump counters to zero
int min_trigger = 59;         // minute            (23 : 59 : 59)
int sec_trigger = 59;         // second             HR   MIN  SEC

int time_hour = timeinfo.tm_hour;   // tm structure element "hour" from time.h
int time_min  = timeinfo.tm_min;    //                     "minute"  "    "
int time_sec  = timeinfo.tm_sec;   //                      "second"
  

boolean counter_reset = false;
4

If you look at your printLocalTime() function, you will notice a declaration

struct tm timeinfo;

but in your constants.h file, you don't declare that anywhere. Any variables declared inside a function are only visible to that function.

5

Aha!!! I did not know this. So much to still learn obviously....lol

thank you very much.... :+1: :+1: :+1:

6

cppCopy code

int current_pump_cycle_min = 10; // Example value, replace with your actual variable
client.print("Current Pump Cycle [minutes] = ");
client.println(current_pump_cycle_min);

Replace current_pump_cycle_min with your actual variable representing the pump cycle duration in minutes. This code will print the message and the value to the client.

7

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