Weather Station Ideas

[Gina]

Went out and pressed EN a couple of times and it now connects but it's not showing the date/time.

[Gina]

Keeping WiFi open fixed the EN problem but I'm still not getting the Date/Time - string is empty.

Added HTML code for paragraph and title of the data in case the HTML was causing the problem and which I should have done anyway but it wasn't that.  Now I can see where the DateTime string should be but it isn't there.

  ptr +="<h1>Gina's ESP32 Weather Station</h1>\n";
  ptr +="<p>Date/Time: ";
  ptr +=DateTime;
  ptr +="</p>";
  ptr +="<h1>Outside Conditions</h1>\n";

[Gina]

Found the problem - me!!  Left some code out!!!

void loop() {
  server.handleClient();
  showLocalTime();         //    <-------------------------  Left this line out!!
  temperatureThen = temperatureNow;
  humidityThen = humidityNow;
  pressureThen = pressureNow;
  ReadBME();
  if (pressureNow > (pressureThen + 0.1)) {pressureDir = "Rising";}
    else if (pressureNow < (pressureThen - 0.1)) {pressureDir = "Falling";}
    else {pressureDir = "No Change";}
  scopeH = dht.readHumidity();
  scopeT = dht.readTemperature();
  delay(2000);
}

 

Edited August 3, 2020 by Gina

[Gina]

Still not right!  Seems there's something wrong with this code:-

void showLocalTime()
  {
  struct tm timeinfo;
  if(!getLocalTime(&timeinfo)){
    DateTime = "Failed to obtain time";
    return;}
    else {DateTime = (&timeinfo, "%A, %B %d %Y %H:%M:%S");}
  }

And yet this works with the Serial Monitor :-

void printLocalTime()
{
  struct tm timeinfo;
  if(!getLocalTime(&timeinfo)){
    Serial.println("Failed to obtain time");
    return;
  }
  Serial.println(&timeinfo, "%A, %B %d %Y %H:%M:%S");
}

Anyone know what I'm doing wrong, please?

[JamesF]

I imagine that Serial.println is overloaded such that when you do:

Serial.println(&timeinfo, "%A, %B %d %Y %H:%M:%S");

then it knows what a "struct tm" is and how to extract the items from it to print them out meaningfully.

I could well be wrong for the Arduino or ESP32, but I don't imagine you can just assign that information to a character pointer or array and have it work.  Were I doing this in C I'd probably look at using sprintf to put the data into a character string.  Something like:

sprintf ( DateTime, "%d/%d/%d %02d:%02d:%02d", timeinfo.tm_mday, timeinfo.tm_mon + 1,
  timeinfo.tm_year + 1900, timeinfo.tm_hour, timeinfo.tm_min, timeinfo.tm_sec );

in the "else" block should work, I think, as long as DateTime is declared as a character array of at least twenty characters.

That won't include pretty stuff like the actual name of the day or month, but it's hopefully a start.

James

Edited August 3, 2020 by JamesF

[Gina]

Hmm... that uses an array of chars rather than a String type.  DateTime is declared as a String type.  This is not a simple as first thought!!

I don't need any of the date/time in words - something like "2020-08-03 14:24" would be fine.  Or maybe "14:24 03/08/2020"  I use the first format in filenames and data logging.

Edited August 3, 2020 by Gina

[pete_l]

1 hour ago, Gina said:

Still not right!  Seems there's something wrong with this code:-

void showLocalTime()
  {
  struct tm timeinfo;
  if(!getLocalTime(&timeinfo)){
    DateTime = "Failed to obtain time";
    return;}
    else {DateTime = (&timeinfo, "%A, %B %d %Y %H:%M:%S");}
  }

 

 

Anyone know what I'm doing wrong, please?

Are you missing a strftime() call?

[JamesF]

49 minutes ago, Gina said:

Hmm... that uses an array of chars rather than a String type.  DateTime is declared as a String type.  This is not a simple as first thought!!

Assuming the "String" type is something similar to the C++ std::string, the only way I know of to do that in C++ is quite cumbersome.

James

[Gina]

Think I've worked it out.

[wimvb]

3 minutes ago, Gina said:

Think I've worked it out.

Otherwise, try the code from your link (lastminuteengineers) as given, ie without the conversion to DateTime.

[Gina]

To save keep going in and out to upload and test, I've arranged the code to work with the Serial Monitor but not needing the Serial Monitor.

This is the result :-  First line is from the Serial.println, the second shows the String DateTime.

This is the code :-

int year, month, day, hour, minute;

void showLocalTime()
  {
  struct tm timeinfo;
  if(!getLocalTime(&timeinfo)){
    DateTime = "Failed to obtain time";
    return;}
    else {
      year = timeinfo.tm_year + 1900;
      month = timeinfo.tm_mon + 1;
      day = timeinfo.tm_mday;
      hour = timeinfo.tm_hour;
      minute = timeinfo.tm_min;
      DateTime = "Date & Time is ";
      DateTime += year;
      DateTime += "-";
      if (month < 10) {DateTime += "0";}
      DateTime += month;
      DateTime += "-";
      if (day < 10) {DateTime += "0";}
      DateTime += day;
      DateTime += "  ";
      if (hour < 10) {DateTime += "0";}
      DateTime += hour;
      DateTime += ":";
      if (minute < 10) {DateTime += "0";}
      DateTime += minute;
      }
  }

 

[jiberjaber]

Isn't DateTime an already defined class?? , to put it another way, are you trying to use a variable that already exists as a reserved for an object definition in Arduino?

 

[Gina]

Don't know but it works when typed as String.

[Gina]

Changed DateTime string to something simpler and better looking IMO.

Now to try it in the obsy.

[jiberjaber]

1 minute ago, Gina said:

Don't know but it works when typed as String.

Yep - it's a Object type in the rtclib - I'd avoid it incase you do decide to use an RTC later as it will clash

(it's sort of the same as type time_t within time.h iirc)

[Gina]

It works!  😀  Could do with being a bit bigger though - not a problem.

[Gina]

Next to get what amounts to a software interrupt working - getting it to build a log of the sensor readings complete with time code and check pressure over a longer period.  I guess the current readings of temperature and humidity are all I need.  I'll add dewpoint calculations though.

Getting near the stage where I want to upload over WiFi too.  Not that the exercise of popping in and out to the obsy isn't good for me 😁

Edited August 3, 2020 by Gina

[Gina]

Replaced all instances of "DateTime" with "myDT".

[jiberjaber]

re: Software interrupt:

I just use millis and a variable to store them in, then compare with a fixed time and if try, do what's needed and reset the variable to the current millis() 

It's basically the foundation of my wxstn code, eg:

// 5 Second task interval
 if ( (millis() - count5sec) >= 5000)
    {
    Tasks5s();        
    count5sec = millis();
    }

(dont forget to init count5sec in the setup() and also define it, eg: unsigned long count5sec; )

Using these I have a 5s, 60s, 30m and 60m 'interrupt' in which I do things - I use a function to wrap them up and put them in a tab in the Arduino IDE to make it a bit more neater, but that's just personal preference... 

 

 

Edited August 3, 2020 by jiberjaber

[Gina]

Groan - lost that showLocalTime(); line again so it isn't updating the time.  Added it now.

Edited August 3, 2020 by Gina

[Gina]

Working now.  Time for a cuppa I think...

[jiberjaber]

Well earned!

 

[Gina]

Getting there - in fits and starts 🤣

[Gina]

Added a 5 minute period and compared pressure.  Taking 0.1hPa difference to trigger Rising or Falling but don't know if 5m is long enough.  Maybe an hour would be better.

I would like an up arrow and a down arrow symbol or character rather than words - any ideas anyone?  Please?

Edited August 3, 2020 by Gina

[jiberjaber]

The ESP has a storage drive on it which you can use and reference in your web pages, you could store an icon on there or reference a png on the net somewhere in the html?