M5unified corrupt ntp time

[kbencherki6-beep]

Hi,
I'm using m5unified in my code and I'm synchronizing time with NTP, but the call to m5.begin() corrupts time. I need m5unified for the power management that I also use.
Here is my code :

`#include <WiFi.h>
#include "time.h"
#include "LittleFS.h"
#include "M5UnitENV.h"
#include <M5Unified.h>
#include <M5GFX.h>

M5GFX display;
M5Canvas canvas(&display);

SHT3X sht30;

RTC_DATA_ATTR int bootCount = 1;

const char* ssid = "";
const char* password = "";

int timeS = 0;

void setup() {
// put your setup code here, to run once:
Serial.begin(115200);
M5.begin();
M5.Power.begin();
display.begin();
sht30.begin();
LittleFS.begin();

display.setEpdMode(epd_fast);

WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
}

configTzTime("WEST0WEST,M3.5.0/1,M10.5.0", "pool.ntp.org");

canvas.createSprite(540, 960);
canvas.setFreeFont(&Orbitron_Light_24);
canvas.fillScreen(WHITE);
canvas.setTextColor(BLACK, WHITE);
canvas.setTextSize(2);

printTimeDate();
printBatteryLevel();
printMeasurements();
canvas.drawPngFile(LittleFS, "/images/m5stack.png", 70, (canvas.height() - canvas.fontHeight() - 20 - 133), 400, 133);
canvas.pushSprite(0, 0);

bootCount++;

delay(5000);

WiFi.disconnect(true);
WiFi.mode(WIFI_OFF);

canvas.fillScreen(BLACK);
display.clear();

esp_sleep_enable_ext0_wakeup(GPIO_NUM_38, LOW);
esp_deep_sleep_start();

}

void loop() {
// put your main code here, to run repeatedly:
}

void printTimeDate(){
struct tm timeinfo;
if(!getLocalTime(&timeinfo)){
Serial.println("Failed to obtain time");
return;
}

char hour[7];
char date[7];
char year[5];  
strftime(hour, 7, "%H:%M", &timeinfo);
Serial.println(hour);
strftime(date, 7, "%d/%m", &timeinfo);
Serial.println(date);
strftime(year, 5, "%Y", &timeinfo);
Serial.println(year);

canvas.fillRect(10, 20, canvas.textWidth(hour), canvas.fontHeight(), WHITE);
canvas.drawString(hour, 10, 20);
canvas.drawLine(0, (canvas.fontHeight() + 20), canvas.width(), (canvas.fontHeight() + 20), BLACK);
canvas.drawLine(0, (canvas.height() - canvas.fontHeight() - 20 - 10), canvas.width(), (canvas.height() - canvas.fontHeight() - 20 -10), BLACK);
canvas.fillRect(10, (canvas.height() - canvas.fontHeight() - 20), canvas.textWidth(date), canvas.fontHeight(), WHITE);
canvas.drawString(date, 10, (canvas.height() - canvas.fontHeight() - 20));
canvas.fillRect((canvas.width() - canvas.textWidth(year) - 10), (canvas.height() - canvas.fontHeight() - 20), canvas.textWidth(year), canvas.fontHeight(), WHITE);
canvas.drawString(year, (canvas.width() - canvas.textWidth(year) - 10), (canvas.height() - canvas.fontHeight() - 20));
}

void printBatteryLevel() {
int32_t batteryLevel = M5.Power.getBatteryLevel();
canvas.setCursor((canvas.width() - canvas.textWidth(String(batteryLevel)) - canvas.textWidth("%") - 10), 20);
canvas.printf("%03d%%", batteryLevel);
}

void printMeasurements() {
if(sht30.update()) {
int temperature = String(sht30.cTemp).toInt();
int humidity = String(sht30.humidity).toInt();
char buffer1[10], buffer2[10];
sprintf(buffer1, "%d", temperature);
sprintf(buffer2, "%d", humidity);
const char* temp = buffer1;
const char* hum = buffer2;

canvas.setTextSize(3);
canvas.drawRect(((canvas.width() / 2) - 200), ((canvas.height() / 2) - 200 - 50), 400, 200, BLACK);
canvas.drawPngFile(LittleFS, "/images/thermometer.png", ((canvas.width() / 2) - 200 + 100), ((canvas.height() / 2) - 200 - 50 + 50), 100, 100);
canvas.drawString(String(temperature), ((canvas.width() / 2) - 200 + 400 - canvas.textWidth(String(temperature)) - 80), ((canvas.height() / 2) - 200 - 50 + 100 - (canvas.fontHeight() / 2)));
canvas.drawRect(((canvas.width() / 2) - 200), ((canvas.height() / 2) + 50), 400, 200, BLACK);
canvas.drawPngFile(LittleFS, "/images/humidity.png", ((canvas.width() / 2) - 200 + 100), ((canvas.height() / 2) + 50 + 50), 100, 100);
canvas.drawString(String(humidity), ((canvas.width() / 2) - 200 + 400 - canvas.textWidth(String(humidity)) - 80), ((canvas.height() / 2) + 50 + 100 - (canvas.fontHeight() / 2)));  

}
}`

[kbencherki6-beep]

Could you please answer me? I don't know what to do to solve this problem.

[ainyan03]

Sorry for the wait. This is expected behaviour of M5.begin() rather than corruption, and there are two ways to make it do what you want.

On boards with an external RTC (the M5Paper here), M5.begin() copies the RTC's time into the system clock every time it runs (M5.Rtc.setSystemTimeFromRtc()). The ESP32's own clock survives deep sleep, so the NTP time you obtained would still be there on wake-up — but M5.begin() then overwrites it with whatever the external RTC holds, and since your sketch never writes the NTP time into the RTC, that is an unset/old value. That is the "corrupted" time you see after each wake.

Fix, either of:

1. Store the NTP time in the RTC once it is synced, so every later M5.begin() restores the correct time (and it survives power loss too):

   configTzTime("WEST0WEST,M3.5.0/1,M10.5.0", "pool.ntp.org");
   struct tm timeinfo;
   if (getLocalTime(&timeinfo)) {        // waits for the first NTP response
     time_t t = time(nullptr);
     M5.Rtc.setDateTime(gmtime(&t));     // RTC keeps UTC; TZ is applied by the libc
   }

2. Or tell M5.begin() not to touch the RTC at all:

   auto cfg = M5.config();
   cfg.internal_rtc = false;
   M5.begin(cfg);

   The system clock then keeps the NTP time across deep sleep on its own.

Option 1 is the usual choice on the Paper, because the RTC is also what keeps time while the device is fully off.