ESP32 Forum

I wrote a captive portal script to capture WiFi credentials, a custom NTP server name, and custom Timezone parameter from a dropdown list to be saved to the NVS. Everything works as expected except the selected timezone parameter is returned as a blank and is not being saved. I am using an ESP32-DevKitC-32E Development Board. The script is compiled with an arduino ide 1.8.19 and an espressif systems core version 2.0.17. The complete script file is attached as a .zip file and as shown.

Any help would be most appreciated

#include <WiFi.h>
#include <WiFiManager.h> // https://github.com/tzapu/WiFiManager
#include <Preferences.h>
#include "RTClib.h"
#include "time.h"

RTC_DS3231 rtc;
Preferences prefs;
WiFiManager wm;

// GPIO for reset button
#define RESET_PIN 33

// POSIX TZ dropdown HTML
const char* tz_html =
"<label for='tz'>Timezone</label>"
"<select name='tz' id='tz'>"
"<option value='UTC0'>UTC</option>"
"<option value='EST5EDT,M3.2.0/2,M11.1.0/2'>US Eastern</option>"
"<option value='CST6CDT,M3.2.0/2,M11.1.0/2'>US Central</option>"
"<option value='MST7MDT,M3.2.0/2,M11.1.0/2'>US Mountain</option>"
"<option value='PST8PDT,M3.2.0/2,M11.1.0/2'>US Pacific</option>"
"</select>";

// Custom parameters
WiFiManagerParameter ntpParam("ntp", "NTP Server", "pool.ntp.org", 40);
WiFiManagerParameter tzParam(tz_html);

String ntpServer;
String timezone;
int last_second = 100;

void setup() {
Serial.begin(115200);
WiFi.mode(WIFI_STA); // explicitly set mode, esp defaults to STA+AP
rtc.begin();
pinMode(RESET_PIN, INPUT_PULLUP);

prefs.begin("config", false);

// Check reset button
if (digitalRead(RESET_PIN) == LOW) {
Serial.println("Reset button pressed — clearing WiFi & config");
prefs.clear();
WiFiManager wm;
wm.resetSettings();
}

// Load saved defaulted values
ntpServer = prefs.getString("ntp", "pool.ntp.org");
timezone = prefs.getString("TZ", "UTC");

std::vector<const char *> wm_menu = {"wifi"}; // only need Configure WiFi bar
// Add custom fields
ntpParam.setValue(ntpServer.c_str(), 40);
wm.setMenu(wm_menu);
wm.addParameter(&ntpParam);
wm.addParameter(&tzParam);
wm.setShowInfoUpdate(false);
wm.setShowInfoErase(false);
wm.setConfigPortalTimeout(180);

// Start captive portal if needed
if (!wm.autoConnect("EPS32 Wifi Setup")) {
Serial.println("Failed to connect — restarting");
delay(1000);
ESP.restart();
}

// Save updated values
prefs.putString("ntp", ntpParam.getValue());
prefs.putString("tz", tzParam.getValue());
ntpServer = ntpParam.getValue();
timezone = tzParam.getValue();
Serial.print("Length of Timezone field selected: ");Serial.println(timezone.length());

Serial.println("Connected!");
Serial.print("NTP: ");Serial.println(ntpServer);
Serial.print("Timezone: ");Serial.println(timezone);

// Next 2 lines commented out until timezone not saving issue is resolved

//configTzTime(timezone.c_str(), ntpServer.c_str());
//syncRTC();
}

void loop() {
DateTime now = rtc.now();
if(last_second != now.second())
{
Serial.printf("%04d-%02d-%02d %02d:%02d:%02d\n",
now.year(), now.month(), now.day(),
now.hour(), now.minute(), now.second());
last_second = now.second();
}
}
void syncRTC() {
struct tm timeinfo;
if (!getLocalTime(&timeinfo)) {
Serial.println("Failed to obtain NTP time");
return;
}

rtc.adjust(DateTime(
timeinfo.tm_year + 1900,
timeinfo.tm_mon + 1,
timeinfo.tm_mday,
timeinfo.tm_hour,
timeinfo.tm_min,
timeinfo.tm_sec
));

Serial.println("RTC updated from NTP");
}

Code: Select all

WiFiManagerParameter tzParam(tz_html);

Pretty sure you'll want to 'bind' the parameter to an 'id' by using one of the other constructors, like you do with

Code: Select all

WiFiManagerParameter ntpParam("ntp", "NTP Server", "pool.ntp.org", 40);

I've added the statement to bind the TZ timezone per your suggestion as shown:

WiFiManagerParameter tzParam("tz","Timezone", "UTC0", 50, tz_html);

The Captive Wifi shows 2 TimeZone selection bars

when I press save, the time zone returned is UTC0 (Which I set as the default in the bind) not the US Central one I selected
I have attached a photo of the situation

regards