All Wemos D1 mini code stopped working after esp8266 Boards upgrade from 2.5.2 to 3.0.2

[TSBrownie]

Basic Info

• [x ] This issue complies with the issue POLICY doc.
• [ x] I have read the documentation at readthedocs and the issue is not addressed there.
• [ ?] I have tested that the issue is present in current master branch (aka latest git).
• [ x] I have searched the issue tracker for a similar issue.
• [ x] If there is a stack dump, I have decoded it.
• [ x] I have filled out all fields below.

Platform

• Hardware: Wemos D1 mini (reports: ESP8266EX) w/ RTC Shield/SD
• Core Version: [latest git hash or date]
• Development Env: 1.8.16
• Operating System: Win 10

Settings in IDE

• Module: Wemos D1 mini ESP8266 3.0.2 (from 2.5.2)
• Flash Mode: qio
• Flash Size: 4MB
• lwip Variant: v2 lower mem
• Reset Method: nodemcu, hard, power
• Flash Frequency: ?? Mhz
• CPU Frequency: Crystal is 26MHz
• Upload Using: SERIAL
• Upload Speed: 460800 (auto set)

Problem Description

Working code (plus 10 past versions) stopped working immediately after updating from Boards esp8266 by ESP8266 Community version 2.5.2 to 3.0.2.
Code still complies w/o error. (Takes take 3x longer.)
I have tried all the Wemos LOLIN boards on the 3.0.2, include generic esp8266. Similar chksum errors from all.

Output before:
========= 20220201,Tue,07:54:28
Device Altitude(abs): 6.00 meters AMSL
Temperature: 28.47C; 83.25F Falling
Barometric Pressure(abs): Rising-Fair Weather
955.597 hPa(mbar); 95559.720 Pa
950.916 hPa, Short Term Past Average
716.757 mmHg
0.943101 Atm
Barometric Pressure-Comp'ed To Sealevel
956.247 hPa(mbar); 95624.692 Pa
717.244 mmHg
0.943742 Atm

Output after:
ets Jan 8 2013,rst cause:4, boot mode:(3,6)
wdt reset
load 0x4010f000, len 3460, room 16
tail 4
chksum 0xcc
load 0x3fff20b8, len 40, room 4
tail 4
chksum 0xc9
csum 0xc9
v00055920
~ld

MCVE Sketch

One sample of previously working code here (compile info below):
https://github.com/TSBrownie/Arduino-Wemos-D1-Weather-Basic/tree/main/2022WeatherBMP280-04x

#include <Arduino.h>
void setup() {}
void loop() {}

Debug Messages

Executable segment sizes:
ICACHE : 32768           - flash instruction cache 
IROM   : 247428          - code in flash         (default or ICACHE_FLASH_ATTR) 
IRAM   : 27369   / 32768 - code in IRAM          (IRAM_ATTR, ISRs...) 
DATA   : 1520  )         - initialized variables (global, static) in RAM/HEAP 
RODATA : 1152  ) / 81920 - constants             (global, static) in RAM/HEAP 
BSS    : 26216 )         - zeroed variables      (global, static) in RAM/HEAP 
Sketch uses 277469 bytes (26%) of program storage space. Maximum is 1044464 bytes.
Global variables use 28888 bytes (35%) of dynamic memory, leaving 53032 bytes for local variables. Maximum is 81920 bytes.
esptool.py v3.0
Serial port COM4
Connecting....
Chip is ESP8266EX
Features: WiFi
Crystal is 26MHz
MAC: e8:db:84:dc:c5:06
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 460800
Changed.
Configuring flash size...
Auto-detected Flash size: 4MB
Compressed 281616 bytes to 205845...
Writing at 0x00000000... (7 %)
Writing at 0x00004000... (15 %)
Writing at 0x00008000... (23 %)
Writing at 0x0000c000... (30 %)
Writing at 0x00010000... (38 %)
Writing at 0x00014000... (46 %)
Writing at 0x00018000... (53 %)
Writing at 0x0001c000... (61 %)
Writing at 0x00020000... (69 %)
Writing at 0x00024000... (76 %)
Writing at 0x00028000... (84 %)
Writing at 0x0002c000... (92 %)
Writing at 0x00030000... (100 %)
Wrote 281616 bytes (205845 compressed) at 0x00000000 in 4.6 seconds (effective 488.2 kbit/s)...
Hash of data verified.

Leaving...
Hard resetting via RTS pin...

NOTE: Simple code such as the following still compiles / works, but only after initially reporting checksums:

//Arduino C.  Wemos D1R1 ESP8266Boards (2.5.2) Mini DS32 w/ Mini Shield.  
//Read Real Time Clock Module DS1307.  COM7.  VCC->5v, Gnd->Gnd, SDA (data)->A4, SCL (clk)->A5
//RTC Pinouts, I2C.  D1 = SCL, D2 = SDA
//20210323 - by TSBrownie.  Non-commercial use approved.
#include "Wire.h"                   //Include I2C library
#define DS1307 0x68                 //Default I2C Addr of 1307 0x68 Hex

String DoWList[] = {"Null"," Sun "," Mon "," Tue "," Wed "," Thr "," Fri "," Sat "}; //DOW from 1-7
byte second, minute, hour, DoW, Date, month, year;     //Btye variables for BCD time
int sec, mm, hh, dow, date, mnth, yy;                  //Decimal variables

byte BCD2DEC(byte val){             //Ex: 51 = 01010001 BCD.  01010001/16-->0101=5 then x10-->50.  
  return(((val/16)*10)+(val%16));}  //         01010001%16-->0001.  50+0001 = 51 DEC

void GetRTCTime(byte *second, byte *minute,byte *hour,byte *DoW,
                byte *Date,byte *month,byte *year){
  Wire.beginTransmission(DS1307);           //Open I2C to RTC
  Wire.write(0x00);                         //Write reg pointer to 0x00 Hex
  Wire.endTransmission();                   //End xmit to I2C.  Send requested data.
  Wire.requestFrom(DS1307, 7);              //Get 7 bytes from RTC buffer
  *second = BCD2DEC(Wire.read() & 0x7f);    //Set pntr to seconds remove hi order bit
  *minute = BCD2DEC(Wire.read());           //Set pointer to minutes
  *hour = BCD2DEC(Wire.read() & 0x3f);      //Set pntr to hour remove 2 hi order bits
  *DoW = BCD2DEC(Wire.read());              //Set pointer to day of week
  *Date = BCD2DEC(Wire.read());             //Set pointer to Date
  *month = BCD2DEC(Wire.read());            //Set pointer to month
  *year = BCD2DEC(Wire.read());             //Set pointer to year
}
void printTime(){                         //Read & print data from RTC
  GetRTCTime(&second, &minute, &hour, &DoW, &Date, &month, &year);  //Get RTC data
  Serial.print(2000+year, DEC);             //Print year 20xx
  Serial.print("/");
  if (month<10){Serial.print("0");}         //Print leading 0 if needed
  Serial.print(month, DEC);                 //Month as decimal
  Serial.print("/");
  if(Date<10){Serial.print("0");}           //Print leading 0 if needed
  Serial.print(Date, DEC);                  //Date (1-30)
  Serial.print(DoWList[DoW]);               //1Sun-7Sat (0=null)
  if (hour<10){Serial.print("0");}          //Print leading 0 if needed
  Serial.print(hour, DEC);                  //HH
  Serial.print(":");        
  if (minute<10){Serial.print("0");}        //Print leading 0 if needed
  Serial.print(minute, DEC);                //MM
  Serial.print(":");
  if (second<10){Serial.print("0");}        //Print leading 0 if needed
  Serial.println(second, DEC);              //SS
}
void setup(){                               //Setup function
  Wire.begin();                             //Join I2C bus as primary
  Serial.begin(74880);                      //Initialize serial com
  for(int i=1; i<5; i++){                   //Read RTC and print date/time for user verify
     printTime();                           //Output date/time to Serial Monitor
     delay(1000);                           //Delay output x seconds
  }
  Serial.println("If the above date and times are correct, the RTC is updated.");
}

void loop(){}                           //Just loops

OUTPUT:
ets Jan 8 2013,rst cause:2, boot mode:(3,6)
load 0x4010f000, len 3460, room 16
tail 4
chksum 0xcc
load 0x3fff20b8, len 40, room 4
tail 4
chksum 0xc9
csum 0xc9
v00042ec0
~ld
2022/02/02 Wed 15:36:42
2022/02/02 Wed 15:36:43
2022/02/02 Wed 15:36:44
2022/02/02 Wed 15:36:45
If the above date and times are correct, the RTC is updated.

[TSBrownie]

Another version of the same weather station code that was working, now does this:

--------------- CUT HERE FOR EXCEPTION DECODER ---------------
Exception (28):
epc1=0x40211734 epc2=0x00000000 epc3=0x00000000 excvaddr=0x00000000 depc=0x00000000
>>>stack>>>
ctx: cont
sp: 3ffffd20 end: 3fffffc0 offset: 0190
3ffffeb0:  00000000 00000000 3ffeebd8 3fff0738  
3ffffec0:  3fff072c 00000003 3ffeea34 40201709  
3ffffed0:  00000000 00000000 3ffffef0 3ffeea9c  
3ffffee0:  3fffff08 3ffeea34 3fffff30 4021184c  
3ffffef0:  40210fa4 00000000 000003e8 40100cd4  
3fffff00:  00000000 00000000 00000000 40204d4c  
3fffff10:  00000000 00000000 3ffeebd8 4020c8d5  
3fffff20:  4020fddc 4020fdc8 3ffee9d8 40201860  
3fffff30:  3fff05b4 000c000f 80000000 4020c9d1  
3fffff40:  4020fddc 4020fdc8 3ffee9d8 40203d00  
3fffff50:  3fff069c 0037003f 80000000 00000000  
3fffff60:  40203488 00000000 4020fddc 4020fdc8  
3fffff70:  40203488 08080808 feefeffe feefeffe  
3fffff80:  00000000 feefeffe feefeffe feefeffe  
3fffff90:  feefeffe feefeffe feefeffe 3ffeeedc  
3fffffa0:  3fffdad0 00000000 3ffeeec8 4020d9c4  
3fffffb0:  feefeffe feefeffe 3ffe8688 40100f2d  
<<<stack<<<

--------------- CUT HERE FOR EXCEPTION DECODER ---------------

THIS IS THE CODE throwing the above errors. This was working archival code:

//Add led on / off during file update if file corruption is issue during eject.
//Arduino Wemos D1R1 mini w/ RTC, SD Shield (ESP8266 Boards 2.5.2), WiFi Viewing
//RTC, SD File: Absolute Barometric Pressure (SL & Comp), Temp, no humidity
//Exponential Moving Average EMA improvement
//Wemos SDA(D2)-->BMP280 SDA pin; Wemos SCL(D1)-->BMP280 SCL
//Wemos 3v3-->BMP280 Vdd; Wemos GND-->BMP280 GND
//UNUSED: Wemos Vdd or GND-->BMP280=SDO (Address control)
//UNUSED: Wemos Vdd or GND-->BMP280=CSB (I2C select, GND=SPI)
//BMP280 Data is LSBMSB ijklmnopabcdefgh order (not abcdefghijklmnop)
//WeMos Micro SD Shield (uses HSPI(12-15) not (5-8), 3V3, G)
//GPIO12(D6)=MISO (main in, secondary out); GPIO13(D7)=MOSI (main out, secondary in) 
//GPIO14(D5)=CLK (Clock); GPIO15(D8)=CS (Chip select)
//SD library-->8.3 filenames (ABCDEFGH.txt = abcdefgh.txt)
//RTC DS1307. I2C--> SCL(clk)=D1, SDA(data)=D2 (Shared with BMP280)
//20220122 - TSBrownie.  Non-commercial use.
#include <SD.h>                      //SD card library
#include <SPI.h>                     //COM Serial Peripheral Interface bus for COMM, SD com

//WiFi Serving Def ===============================
#include <ESP8266WiFi.h>             //WiFi library
#include <WiFiClient.h>              //WiFi Client library
#include <ESP8266WebServer.h>        //Web Server library
#include <DNSServer.h>               //Domain Name Server
#include <ESP8266mDNS.h>             //ESP8266 mDNS specific
#include <EEPROM.h>                  //ESP eeprom library
#define DBG_OUTPUT_PORT Serial       //Direct debug to Serial
//Set to desired softAP credentials. NOT configurable at runtime
#ifndef APSSID                       //Prevents incursive lib inclusions
#define APSSID "FreeLocalWeather"    //USER SUPPLIED: SSID
#define APPSK  ""                    //#define APPSK  "12345678"
#endif                               //

const char *softAP_ssid = APSSID;    //Soft access point ssid (def above)
const char *softAP_password = APPSK; //Soft access point password (def above)
const char *myHostname = "FreeInfo"; //Hostname for multicast DNS. Works on win. Try http://esp8266.local
char ssid[32] = "";                  //Don't set this credential. Configured at runtime & stored on EEPROM
char password[32] = "";              //Don't set this credential. Configured at runtime & stored on EEPROM
const byte DNS_PORT = 53;            //DNS server.  Port 53 for UDP activities & as server port for TCP
DNSServer dnsServer;                 //DNS server.  Port 53 for UDP activities & as server port for TCP
ESP8266WebServer server(80);         //Port 80, standard internet
IPAddress apIP(8, 8, 8, 8);          //Soft AP network parameters 8888 for auto show
IPAddress netMsk(255, 255, 255, 0);  //Soft AP network parameters
const int msgLen = 57;               //Xfer client confirm message length
char msg[msgLen];                    //Final confirm msg to client.  2GB file limit
//End WiFi Serving Def ===========================
#include<Wire.h>                     //Wire library I2C
#define BMP280Addr 0x76              //BMP280 I2C 0x76(108), or 0x77
#define DS1307 0x68                  //I2C Addr of RTC1307 (Default=0x68 Hex)
#define S_prt Serial.print           //Short name for Serial.print
#define S_pln Serial.println         //Short name for Serial.println
File SDconFile;                      //SD File2 to keep connect info
File saveWeather;                    //SD file3 keep all weather data
File dataTemp;                       //SD file4 txt temp weather data to show
const char *FName2 = "Connect1.txt"; //USER: SD card file keep connect info
const char *FName3 = "20220122.txt"; //USER SUPPLIED: SD card file name (ANSI encoding is best)
String FName4 = "DataTemp.txt";      //USER: SD temp display data (not const char) 
String connectData;                  //Accumulate SD connect data
String outBuff;                      //Output to COM and SD file
String SDData;                       //Build data to write to SD "disk"
String timeString;                   //Build date time data
unsigned long time_last = 0;         //Last time data was updated for millis()
unsigned int time2update = 10000;    //USER SUPPLIED: Milliseconds between readings
double calib = 0;                    //USER SUPPLIED: Clock calibration
double TempCal = -5;                 //USER SUPPLIED: Temp C calibration factor
double Dh = 6.0;                     //USER SUPPLIED: Device height above sea level m
double P, p0;                        //P Uncomp Press at device alt, p0 Sea Level
double cTempLast = 0;                //Keep last temp for rising, falling, steady
double pLast = 0;                    //Keep last pressure for rising, falling, steady
unsigned int b1[24];                 //16 bit array 0-24 (2 bytes)
unsigned int data[8];                //16 bit Data array 0-8
unsigned int avgPTindx = 0;          //Index to avgPT
unsigned int con = 0;                //Number of user connects since startup 
const unsigned int avgPTsz = 10;     //USER SUPPLIED: # of past data to average,size of avgPT array
//const unsigned int Nreadings = 10; //USER SUPPLIED: # of data points to average,size of avgPT array
//float Kconst = 0.18181818;         //USER SUPPLIED K = 2 / (N+1) N=Number of readings stored
double avgPT[2][avgPTsz+1];          //Store past press & temp for averages
bool avgFlag = false;                //Suppress avg press until enough samples
byte second, minute, hour, DoW, Date, month, year;   //Btye variables for BCD time
const char *DoWList[]={"Null",",Sun,",",Mon,",",Tue,",",Wed,",",Thr,",",Fri,",",Sat,"}; //DOW from 1-7

int Compare(float f1, float f2, int ex1){                   //Compare(F1, F2, # decimal places)
  if (round(f1 * pow(10,ex1)) > (round(f2 * pow(10,ex1)))){ //Compare ex1 decimals           
     return(1);}
     else if (round(f1*pow(10,ex1)) < (round(f2*pow(10,ex1)))){  //Compare ex1 decimals
       return(-1);}
       else return(0);
}

void avgPTCalc(){                     //Calc all avgs
  avgPT[0][0] = 0;                    //Init Press accumulator
  avgPT[1][0] = 0;                    //Init Temp accumulator
  for(int k=1; k<=avgPTsz; k++){      //Loop thru avg readings
    avgPT[0][0] += avgPT[0][k];       //Add to accumulator for P
    avgPT[1][0] += avgPT[1][k];       //Add to accumulator for T
  }
  avgPT[0][0] = avgPT[0][0]/avgPTsz;  //Put average P at loc 0
  avgPT[1][0] = avgPT[1][0]/avgPTsz;  //Put average T at loc 0
}
/*
void EMACalcPT(){                     //Exp Moving Avg Calc
  //EMAcur = (ValueCur*(Smoothing/(1+days)))+EMAlast*(1-(Smoothing/(1+days)))
  //EMA=Value(t) × k + EMA(y) × (1 − k); where:t=today; y=yesterday; N=number of days in EMA; k=2÷(N+1)
  //Kconst
  //avgPT[0][0] = 0;                    //Init Press last
  //avgPT[1][0] = 0;                    //Init Temp last

  avgPT[0][0] = (avgPT[0][avgPTindx] * Kconst) + (avgPT[0][0] * (1 - Kconst)); //Kconst= 2/(N+1)
  S_pln(avgPT[0][avgPTindx] * Kconst + avgPT[0][0] * (1 - Kconst)); //Kconst= 2/(N+1)
  S_pln((avgPT[0][avgPTindx] * Kconst) + (avgPT[0][0] * (1 - Kconst))); //Kconst= 2/(N+1)
  
  
  for(int k=1; k<=avgPTsz; k++){      //Loop thru avg readings
    avgPT[0][0] = avgPT[0][k];       //Add to accumulator for P
    avgPT[1][0] = avgPT[1][k];       //Add to accumulator for T
  }
  avgPT[0][0] = avgPT[0][0]/avgPTsz;  //Put average P at loc 0
  avgPT[1][0] = avgPT[1][0]/avgPTsz;  //Put average T at loc 0
}
*/

//RTC FUNCTIONS =====================================
byte BCD2DEC(byte val){               //Ex: 51 = 01010001 BCD. 01010001/16-->0101=5 then x10-->50  
  return(((val/16)*10)+(val%16));}    //         01010001%16-->0001. 50+0001 = 51 DEC

void GetRTCTime(){                               //Routine read real time clock, format data
  byte second;byte minute;byte hour;byte DoW;byte Date;byte month;byte year;
  Wire.beginTransmission(DS1307);                //Open I2C to RTC DS1307
  Wire.write(0x00);                              //Write reg pointer to 0x00 Hex
  Wire.endTransmission();                        //End xmit to I2C.  Send requested data.
  Wire.requestFrom(DS1307, 7);                   //Get 7 bytes from RTC buffer
  second = BCD2DEC(Wire.read() & 0x7f);          //Seconds.  Remove hi order bit
  minute = BCD2DEC(Wire.read());                 //Minutes
  hour = BCD2DEC(Wire.read() & 0x3f);            //Hour.  Remove 2 hi order bits
  DoW = BCD2DEC(Wire.read());                    //Day of week
  Date = BCD2DEC(Wire.read());                   //Date
  month = BCD2DEC(Wire.read());                  //Month
  year = BCD2DEC(Wire.read());                   //Year
  timeString = 2000+year;                        //Build Date-Time data to write to SD
  if (month<10){timeString = timeString + '0';}  //Pad leading 0 if needed
  timeString = timeString + month;               //Month (1-12)  
  if(Date<10){timeString = timeString + '0';}    //Pad leading 0 if needed
  timeString = timeString + Date;                //Date (1-30)
  timeString = timeString + DoWList[DoW];        //1Sun-7Sat (0=null)
  if (hour<10){timeString = timeString + '0';}   //Pad leading 0 if needed
  timeString = timeString + hour + ':';          //HH (0-24)
  if (minute<10){timeString = timeString + '0';} //Pad leading 0 if needed
  timeString = timeString + minute + ':';        //MM (0-60)
  if (second<10){timeString = timeString + '0';} //Pad leading 0 if needed
  timeString = timeString + second;              //SS (0-60)
}

//SD CARD FUNCTIONS =================================
void openSD() {                          //Routine to open SD card
  S_pln(); S_pln("Open SD card");        //User message
  if (!SD.begin(15)) {                   //If not open, print message.
    S_pln("Open SD card failed");
    return;}
  S_pln("SD Card open");
}

//char openFile2(byte RW, String FN) {     //Open SD FName2 file. char RW. Only 1 at a time.
//  SDconFile.close();                     //Ensure file status, before re-opening
//  SDconFile = SD.open(FN, RW);}          //Open Read at end.  Open at EOF for write/append

char openFile3(byte RW, String FN) {     //Open SD FName3 file. char RW. Only 1 at a time.
  saveWeather.close();                   //Ensure file status, before re-opening
  saveWeather = SD.open(FN, RW);}        //Open Read at end.  Open at EOF for write/append

char openFile4(byte RW, String FN) {     //Open SD FName3 file. char RW. Only 1 at a time.
  dataTemp.close();                      //Ensure file status, before re-opening
  dataTemp = SD.open(FN, RW);            //Open Read at end.  Open at EOF for write/append
//  digitalWrite(LED_BUILTIN, LOW);        //D1 Mini: turns LED *on*. Eject SD if off
  }

/*void print2File(String C){               //Write connect data to SD file
  openFile2(FILE_WRITE, FName2);         //Open SD connect file Write
  if (SDconFile) {                       //If file there & opened --> write
    SDconFile.println(C);                //Write to SD
    SDconFile.close();                   //Close file, flush buffer (reliable but slow)
  } else {                               //File didn't open
    Serial.println("Error opening Connect file for write");
  }
}
*/

void print2File(String C){               //Write connect data to SD file
  SDconFile.close();                     //Ensure file status, before re-opening
  SDconFile = SD.open(FName2, FILE_WRITE); //Open Read at end.  Open at EOF for write/append
  if (SDconFile) {                       //If file there & opened --> write
    SDconFile.println(C);                //Write to SD
    SDconFile.close();                   //Close file, flush buffer (reliable but slow)
  } else {                               //File didn't open
    Serial.println("Error opening Connect file for write");
  }
}



void print3File(String tmp1) {         //Print data to SD file
  openFile3(FILE_WRITE,FName3);          //Open user SD file for write
  if (saveWeather) {                     //If file there & opened --> write
    saveWeather.println(tmp1);           //Print string to file
    saveWeather.close();                 //Close file, flush buffer (reliable but slower)
  } else {S_pln("Error opening saveWeather file for write");}   //File didn't open
}

void print4File(String tmp1) {         //Print data to SD file
  openFile4(FILE_WRITE,FName4);          //Open user SD file for write
  if (dataTemp) {                        //If file there & opened --> write
    dataTemp.println(tmp1);              //Print string to file
    dataTemp.close();                    //Close file, flush buffer (reliable but slower)
//    digitalWrite(LED_BUILTIN, HIGH);     //D1 Mini: turns LED *on*.Eject SD if off
  } else {S_pln("Error opening dataTemp file for write");}   //File didn't open
}

void initTempFile(){                     //Initialize SD card connect file
  SDconFile.close();                     //Ensure file is closed         
  SD.remove(FName4);                     //Delete connection info file
  SDconFile.close();                     //Ensure file status, before re-opening
  SDconFile = SD.open(FName4, FILE_WRITE); //Open Read at end.  Open at EOF for write/append
//  openFile2(FILE_WRITE, FName4);         //Open SD connect file Write
  SDconFile.close();                     //Close SD connect file
//  server.send(200, "text/html", "Connect Data File Initialized");
}
//End SD Card FUNCTIONS ====================
//Web Routines =============================
void handleRoot(){ 
  openFile4(FILE_READ, FName4);                                  //Open SD file for read
  int SDfileSz = dataTemp.size();                                //Get file size
  Serial.print("SDfileSz: ");  Serial.println(SDfileSz);         //Data file size
  server.sendHeader("Content-Length", (String)(SDfileSz));       //Header info
  server.sendHeader("Cache-Control", "max-age=2628000, public"); //Cache 30 days
  String dataType = "text/plain";
  if(FName4.endsWith("/")) FName4 += "index.htm";
  if(FName4.endsWith(".src")) FName4 = FName4.substring(0, FName4.lastIndexOf("."));
  else if(FName4.endsWith(".html")) dataType = "text/html";
  else if(FName4.endsWith(".mhtml")) dataType = "text/mhtml";
  else if(FName4.endsWith(".css")) dataType = "text/css";
  else if(FName4.endsWith(".js")) dataType = "application/javascript";
  else if(FName4.endsWith(".png")) dataType = "image/png";
  else if(FName4.endsWith(".gif")) dataType = "image/gif";
  else if(FName4.endsWith(".jpg")) dataType = "image/jpeg";
  else if(FName4.endsWith(".ico")) dataType = "image/x-icon";
  else if(FName4.endsWith(".xml")) dataType = "text/xml";
  else if(FName4.endsWith(".pdf")) dataType = "application/pdf";
  else if(FName4.endsWith(".zip")) dataType = "application/zip";
  size_t fsizeSent = server.streamFile(dataTemp, dataType);      //
  Serial.print("fsizeSent: "); Serial.println(fsizeSent);        //Size sent data
  dataTemp.close();                                              //Close SD file
  delay(100);                                        //File settling time

GetRTCTime();                                        //Get time from RTC
  connectData = String(timeString+','+con++);        //SD connects data
  Serial.println(connectData);                       //Print connect data to serial
  print2File(connectData);                           //Write connect data to SD
  delay(100);                                        //File settling time
}

void handleNotFound() {                              //Server Errors
  String message = F("File Not Found\n\n");
  message += F("URI: ");
  message += server.uri();
  message += F("\nMethod: ");
  message += (server.method() == HTTP_GET) ? "GET" : "POST";
  message += F("\nArguments: ");
  message += server.args();
  message += F("\n");
  for (uint8_t i = 0; i < server.args(); i++) {
    message += String(F(" ")) + server.argName(i) + F(": ") + server.arg(i) + F("\n");}
  server.sendHeader("Cache-Control", "no-cache, no-store, must-revalidate");
  server.sendHeader("Pragma", "no-cache");
  server.sendHeader("Expires", "-1");
  server.send(404, "text/plain", message);
}
//End Web Routines =========================
//SETUP ===============
void setup(){                            //SETUP()
//  pinMode(LED_BUILTIN, OUTPUT);          //Set pin D4 (GPIO2) for LED. Safe SD eject
  Wire.begin();                          //Init I2C com
  Serial.begin(115200);                  //Init Serial com
  delay(1000);                           //Allow serial to come online
  S_pln("Connecting to network ");       //User msg
  WiFi.softAPConfig(apIP, apIP, netMsk); //Soft access point set IP, mask
  WiFi.softAP(softAP_ssid, softAP_password);  //Remove password parameter for open AP
  delay(500);                            //500 Delay to avoid blank IP address
  Serial.print("AP IP address: ");
  Serial.println(WiFi.softAPIP());
  dnsServer.setErrorReplyCode(DNSReplyCode::NoError);  //Setup DNS server redirecting all the domains to apIP
  dnsServer.start(DNS_PORT, "*", apIP);  //Setup DNS server redirecting all the domains to apIP
  server.on("/", handleRoot);            //First web input
  server.on("/generate_204", handleRoot);//Android captive portal. Maybe not needed. Might be handled by notFound handler.
  server.on("/fwlink", handleRoot);      //Microsoft captive portal. Maybe not needed. Might be handled by notFound handler.
  server.on("/initfile", initTempFile);  //Data request
  server.onNotFound(handleNotFound);     //Handle not found error
  server.begin();                        //Start server
  Serial.println("HTTP Server Started"); //User info
  
  openSD();                              //Call open SD card routine
  GetRTCTime();                          //Get time from real time clock
  SDData = String("RecType,DeviceAlt,DateTime,DevicehPa,SeaLevel-hPa,TempC"); //File Header
  print3File(SDData);                    //Write string to SD file
  SDData = "C,"+timeString+calib;        //Prepare calibration string
  print3File(SDData);                    //Write string to SD file
//  outBuff = String("RecType,DeviceAlt,DateTime,DevicehPa,SeaLevel-hPa,TempC"); //File Header
//  print3File(outBuff);                   //Write string to SD file
//  outBuff = "C,"+timeString+calib;       //Prepare calibration string
//  print3File(outBuff);                   //Write string to SD file

}
//LOOP ===============
void loop(){                             //LOOP()
  dnsServer.processNextRequest();        //DNS NECESSARY
  server.handleClient();                 //Handle client calls
  for (int i = 0; i < 24; i++)  {        //Get data 1 reg (2 bytes, 16 bits) at a time
    Wire.beginTransmission(BMP280Addr);  //Begin I2C to BMx280
    Wire.write((136 + i));               //Data register 136-159 (0x88-0x9F)
    Wire.endTransmission();              //End I2C Transmission
    Wire.requestFrom(BMP280Addr, 1);     //Get BMx280 1 byte data in LSBMSB order
    if (Wire.available() == 1){          //If device available
      b1[i] = Wire.read();}              //Read reg, store in b1[0-23]
  }
  
  //Temperature coefficients (byte1: LSB<>MSB, bitwise & 11111111; byte 2 same+shift)
  unsigned int dig_T1=(b1[0] & 0xFF)+((b1[1] & 0xFF)*256); //0x88/0x89 
  int dig_T2 = b1[2] + (b1[3] * 256);    //0x8A/0x8B
  int dig_T3 = b1[4] + (b1[5] * 256);    //0x8C/0x8D

  //Pressure coefficients (byte1: LSB<>MSB, bitwise & 11111111; byte 2 same+shift)
  unsigned int dig_P1=(b1[6] & 0xFF)+((b1[7] & 0xFF)*256);//0x8E/0x8F
  int dig_P2 = b1[8] + (b1[9] * 256);    //0x90/0x91
  int dig_P3 = b1[10] + (b1[11] * 256);  //0x92/0x93
  int dig_P4 = b1[12] + (b1[13] * 256);  //0x94/0x95
  int dig_P5 = b1[14] + (b1[15] * 256);  //0x96/0x97
  int dig_P6 = b1[16] + (b1[17] * 256);  //0x98/0x99
  int dig_P7 = b1[18] + (b1[19] * 256);  //0x9A/0x9B
  int dig_P8 = b1[20] + (b1[21] * 256);  //0x9C/0x9D
  int dig_P9 = b1[22] + (b1[23] * 256);  //0x9E/0x9F

  Wire.beginTransmission(BMP280Addr);    //Start I2C Transmission BMx280
  Wire.write(0xF4);                      //Select control measurement register
  Wire.write(0x27);                      //Set normal mode, temp & press over-sampling rate = 1
  Wire.endTransmission();                //End I2C Transmission
  Wire.beginTransmission(BMP280Addr);    //Start I2C Transmission BMx280
  Wire.write(0xF5);                      //Select Config register
  Wire.write(0xA0);                      //Set stand_by time = 1000ms
  Wire.endTransmission();                //End I2C Transmission to get data
  for (int i = 0; i < 8; i++){           //Collect temp & press data
    Wire.beginTransmission(BMP280Addr);  //Start I2C Transmission BMx280
    Wire.write((247 + i));               //Select data register
    Wire.endTransmission();              //End I2C Transmission
    Wire.requestFrom(BMP280Addr, 1);     //Request 1 byte of data from BMx280
    if (Wire.available() == 1){          //If data
      data[i] = Wire.read();}            //Read & store 1 byte of data
  }

  //Convert pressure & temperature data to 19-bits
  long adc_p = (((long)(data[0] & 0xFF) * 65536) + ((long)(data[1] & 0xFF) * 256) + (long)(data[2] & 0xF0)) / 16;
  long adc_t = (((long)(data[3] & 0xFF) * 65536) + ((long)(data[4] & 0xFF) * 256) + (long)(data[5] & 0xF0)) / 16;

  //Temperature offset calculations (per Bosch)
  double var1 = (((double)adc_t) / 16384.0 - ((double)dig_T1) / 1024.0) * ((double)dig_T2);
  double var2 = ((((double)adc_t) / 131072.0 - ((double)dig_T1) / 8192.0) *
                 (((double)adc_t) / 131072.0 - ((double)dig_T1) / 8192.0)) * ((double)dig_T3);
  double t_fine = (long)(var1 + var2);              //
  double cTemp = ((var1 + var2) / 5120.0) + TempCal;//Calc C, add calibration factor
  double fTemp = cTemp * 1.8 + 32;                  //Convert C to F

  //Pressure offset calculations (per Bosch)
  var1 = ((double)t_fine / 2.0) - 64000.0;          //
  var2 = var1 * var1 * ((double)dig_P6) / 32768.0;  //
  var2 = var2 + var1 * ((double)dig_P5) * 2.0;      //
  var2 = (var2 / 4.0) + (((double)dig_P4) * 65536.0); //
  var1 = (((double) dig_P3) * var1 * var1 / 524288.0 + ((double) dig_P2) * var1) / 524288.0;
  var1 = (1.0 + var1 / 32768.0) * ((double)dig_P1); //
  double p = 1048576.0 - (double)adc_p;
  p = (p - (var2 / 4096.0)) * 6250.0 / var1;        //
  var1 = ((double) dig_P9) * p * p / 2147483648.0;  //
  var2 = p * ((double) dig_P8) / 32768.0;           //
  double pressure = (p + (var1 + var2 + ((double)dig_P7)) / 16.0) / 100; //hPa

  //OUTPUT TO SERIAL MONITOR + WiFi CONNECTIONS
  if(millis() >= time_last + time2update){          //Delay data update per user
    time_last += time2update;                       //Keep last time of update
    initTempFile();                                 //Reset the temp file, fill with current data
    p0 = ((pressure/100) * pow(1 - (0.0065 * Dh / (cTemp + 0.0065 * Dh + 273.15)), -5.257));
    avgPTCalc();                                    //Calculate averages
    outBuff = "========= " + String(timeString); 
    S_pln(outBuff);print4File(outBuff);
    outBuff = "Device Altitude(abs): "+ String(Dh)+" meters AMSL";
    S_pln(outBuff);print4File(outBuff);
//    outBuff = "Temperature: "+String(cTemp)+("°C; ")+String(fTemp)+"°F  ";
    outBuff = "Temperature: "+String(cTemp)+("C; ")+String(fTemp)+"F  ";
    if (Compare(cTemp,avgPT[1][0],1) == 1){         //Compare(F1,F2,# decimal places compared)
        S_pln(outBuff+"Rising");print4File(outBuff+"Rising");} //If temp is rising from prior
      else if(Compare(cTemp,avgPT[1][0],1) == -1){      
        S_pln(outBuff+"Falling");print4File(outBuff+"Falling");}      //If temp is falling from prior 
        else {S_pln(outBuff+"Steady");print4File(outBuff+"Steady");}  //Else steady
  
    outBuff = "Barometric Pressure(abs): ";
    if (Compare(pressure,avgPT[0][0],1) == 1){      //Compare(F1, F2, # decimal places compared)
      if(avgFlag){outBuff+="Rising-Fair Weather";}} //If press is rising from prior
      else if(Compare(pressure,avgPT[0][0],1) == -1){
        if(avgFlag){outBuff+="Falling-Stormy";}}    //If press is falling from prior
        else {if(avgFlag){outBuff+="Steady-No Change";}}   //Else steady
    S_pln(outBuff);print4File(outBuff);             //Output buffer string
      
    if(avgPTindx >= avgPTsz){                       //Circular index to averages
      avgPTindx = 1;                                //If too big-->reset to 1
      avgFlag = true;}                              //Display average press
      else {avgPTindx++;}                           //Increment index
    avgPT[0][avgPTindx] = pressure;                 //Save press to avg
    avgPT[1][avgPTindx] = cTemp;                    //Save temp to avg
  
    outBuff = "  "+String(pressure, 3)+" hPa(mbar); "+String(pressure * 100, 3)+" Pa"; //Print Pressure in Pa mbar
    S_pln(outBuff);print4File(outBuff);
    outBuff = "  "+String(avgPT[0][0], 3)+" hPa, Short Term Past Average "; //Avg Pressure
    if(avgFlag){S_pln(outBuff);print4File(outBuff);}                        //Avg Press if available
    outBuff = "  "+String(pressure * 0.750061683, 3)+" mmHg"; //Print Pressure in mmHg
    S_pln(outBuff);print4File(outBuff);
    outBuff = "  "+String(pressure * 0.000986923, 6)+" Atm ";//Print Pressure in atm
    S_pln(outBuff);print4File(outBuff);
    outBuff = "Barometric Pressure-Comp'ed To Sealevel";
    S_pln(outBuff);print4File(outBuff);
    outBuff = "  "+String(p0 * 100, 3)+" hPa(mbar); "+String(p0 * 10000, 3)+" Pa";//Comp'ed Pressure in Pa, mbar, hPa
    S_pln(outBuff);print4File(outBuff);
    outBuff = "  "+String(p0 * 075.0061683, 3)+" mmHg";       //Comp'ed Pressure in mmHg
    S_pln(outBuff);print4File(outBuff);
    outBuff = "  "+String(p0 * 000.0986923, 6)+" Atm ";      //Comp'ed Pressure in Atm
    S_pln(outBuff);print4File(outBuff);
   
    GetRTCTime();                                             //Get time from RTC
//    SDData = "D,"+String(Dh)+','+timeString+','+
//      String(pressure)+','+String(p0*100)+','+String(cTemp);  //Ongoing SD weather data
//    print3File(SDData);                                       //Write weather data to SD

    outBuff = "D,"+String(Dh)+','+timeString+','+
      String(pressure)+','+String(p0*100)+','+String(cTemp);  //Ongoing SD weather data
    print3File(outBuff);                                       //Write weather data to SD

  }                                                           //End: if(millis() >= time_last + time2update)
}                                                             //End: Loop()

[d-a-v]

Thanks for the report.
Please use the exception decoder for your stack trace above.

[TSBrownie]

I used github's code sample. Ran it. It blew up.
Copied the dump (below), but
IDE 1.8.16 does not have the ESP exception decoder.

ctx: cont
sp: 3ffffdf0 end: 3fffffc0 offset: 01a0
3fffff90:  3fffdad0 00000000 3ffee4f8 40201050  
3fffffa0:  feefeffe feefeffe 3ffee54c 40201894  
3fffffb0:  feefeffe feefeffe 3ffe85d8 40100b51  

I have been testing all my Wemos code from simple to 500 line programs
and none of it works; most of it produces chksums or such, some of it
produces Serial COM output, but anything that's not just text (ex: numbers)
is either junk, or wrong (probably from memory issues).

I used to write code for GE/Honeywell mainframes in the late 1970s, and
that's the last time I dug through a dump. Now I'm coding for fun,
but when all your code goes bad because of a board library change, that
sucks. Any suggestions on low power boards with solid support? (And RTCs, SD
cards, etc?)
Thanks.

[d-a-v]

but IDE 1.8.16 does not have the ESP exception decoder.

You must install it as instructed in the documentation. No one except you can decode the stack trace.

I have been testing all my Wemos code from simple to 500 line programs
and none of it works

Did you try the erase "All flash" arduino IDE option ?

[Bighoneypot]

@TSBrownie

Try this tool

https://www.filemail.com/d/nzlpfgbjpananhv

[TSBrownie]

but IDE 1.8.16 does not have the ESP exception decoder.

You must install it as instructed in the documentation. No one except you can decode the stack trace.

I have been testing all my Wemos code from simple to 500 line programs
and none of it works

Did you try the erase "All flash" arduino IDE option ?
Yes, I tried all 3 options. No difference.

EXCEPTION DECODER:
Decoding stack results
0x40201050: setup() at D:\Prgms\Arduino\ArduinoWemosD1\2022GithubExceptDecode01a/2022GithubExceptDecode01a.ino line 22
0x40201894: loop_wrapper() at C:\Users\Family\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\3.0.2\cores\esp8266\core_esp8266_main.cpp line 198

---

--------------- CUT HERE FOR EXCEPTION DECODER ---------------

Soft WDT reset

stack>>>

ctx: cont
sp: 3ffffdf0 end: 3fffffc0 offset: 01a0
3fffff90: 3fffdad0 00000000 3ffee4f8 40201050
3fffffa0: feefeffe feefeffe 3ffee54c 40201894
3fffffb0: feefeffe feefeffe 3ffe85d8 40100b51
<<<stack<<<

--------------- CUT HERE FOR EXCEPTION DECODER ---------------

[TSBrownie]

@TSBrownie

Try this tool

https://www.filemail.com/d/nzlpfgbjpananhv
Your user name is "Bighoneypot" and you are offering a link to an unknown source?
Hmmmmmmm.

[Bighoneypot]

@TSBrownie
You're nice ;-)

My drive
https://drive.google.com/drive/folders/1D1lp4OoMuAaTxWt1QXtWsm0RYKwtgMQQ?usp=sharing

Try it!

[TSBrownie]

This is a video of Setting the Real Time Clock (code from above) showing it worked when it was compiled using Board 2.5.2.
https://www.youtube.com/watch?v=dAs0Xzp2GdQ

[mcspr]

Note that the code from #8475 (comment) cannot be built using 3.0.2 with warnings enabled

/home/builder/dev/arduino8475/src/main.ino: In function 'void avgPTCalc()':
/home/builder/dev/arduino8475/src/main.ino:92:17: warning: comparison of integer expressions of different signedness: 'int' and 'const unsigned int' [-Wsign-compare]
   92 |   for(int k=1; k<=avgPTsz; k++){      //Loop thru avg readings
      |                ~^~~~~~~~~
/home/builder/dev/arduino8475/src/main.ino: In function 'char openFile3(byte, String)':
/home/builder/dev/arduino8475/src/main.ino:167:33: error: no return statement in function returning non-void [-Werror=return-type]
  167 |   saveWeather = SD.open(FN, RW);}        //Open Read at end.  Open at EOF for write/append
      |                                 ^
/home/builder/dev/arduino8475/src/main.ino: In function 'char openFile4(byte, String)':
/home/builder/dev/arduino8475/src/main.ino:173:3: error: no return statement in function returning non-void [-Werror=return-type]
  173 |   }
      |

I suppose that is b/c you are using 'no-warnings' option?
Can you retry by either using void as return type for openFile3 and openFile4 or add return with some meaningful value?

[TSBrownie]

Note that the code from #8475 (comment) cannot be built using 3.0.2 with warnings enabled

/home/builder/dev/arduino8475/src/main.ino: In function 'void avgPTCalc()':
/home/builder/dev/arduino8475/src/main.ino:92:17: warning: comparison of integer expressions of different signedness: 'int' and 'const unsigned int' [-Wsign-compare]
   92 |   for(int k=1; k<=avgPTsz; k++){      //Loop thru avg readings
      |                ~^~~~~~~~~
/home/builder/dev/arduino8475/src/main.ino: In function 'char openFile3(byte, String)':
/home/builder/dev/arduino8475/src/main.ino:167:33: error: no return statement in function returning non-void [-Werror=return-type]
  167 |   saveWeather = SD.open(FN, RW);}        //Open Read at end.  Open at EOF for write/append
      |                                 ^
/home/builder/dev/arduino8475/src/main.ino: In function 'char openFile4(byte, String)':
/home/builder/dev/arduino8475/src/main.ino:173:3: error: no return statement in function returning non-void [-Werror=return-type]
  173 |   }
      |

I suppose that is b/c you are using 'no-warnings' option? Can you retry by either using void as return type for openFile3 and openFile4 or add return with some meaningful value?

Do you mean Tools -->Debug Level: None??? or Exceptions: Disabled???

[mcspr]

Do you mean Tools -->Debug Level: None??? or Exceptions: Disabled???

Debug Level one

[TSBrownie]

Uninstalled IDE 1.8.16, installed 1.8.19, and esp8266 by ESP8266 Community. Tried versions below on the weather program above (closed IDE between each upgrade + "Erase all flash content" + hardware reset of Wemos).
2.5.2 --> Compiles. Runs correctly.
2.6.2 --> Compiles. Runs correctly.
2.7.2 --> Compiles. Runs correctly.
2.74 --> Compiles. Runs correctly.
3.0.0 --> Compiles, but gives similar runtime error as above
3.0.1 --> Compiles, but gives similar runtime error as above
3.0.2 --> Compiles, but gives the runtime errors shown above

Then I tried a simple program that reads the Wemos D1 mini SD card/RTC shield's clock (per above).
2.5.2 --> Compiles. Runs correctly.
2.6.2 --> Compiles. Runs correctly.
2.7.2 --> Compiles. Runs correctly.
2.7.4 --> Compiles. Runs correctly, but prints out the following line mid-output.
"SDK:2.2.2-dev(38a443e)/Core:2.7.3-3-g2843a5ac=20703003/lwIP:STABLE-2_1_2_RELEASE/glue:1.2-30-g92add50/BearSSL:5c771be"

3.0.0 --> Compiles, Runs correctly.
3.0.1 --> Compiles, Runs correctly.
3.0.2 --> Compiles, Runs correctly but prints out the following line mid-output
"SDK:2.2.2-dev(38a443e)/Core:3.0.2=30002000/lwIP:STABLE-2_1_2_RELEASE/glue:1.2-48-g7421258/BearSSL:6105635"

[TSBrownie]

Note that the code from #8475 (comment) cannot be built using 3.0.2 with warnings enabled

/home/builder/dev/arduino8475/src/main.ino: In function 'void avgPTCalc()':
/home/builder/dev/arduino8475/src/main.ino:92:17: warning: comparison of integer expressions of different signedness: 'int' and 'const unsigned int' [-Wsign-compare]
   92 |   for(int k=1; k<=avgPTsz; k++){      //Loop thru avg readings
      |                ~^~~~~~~~~
/home/builder/dev/arduino8475/src/main.ino: In function 'char openFile3(byte, String)':
/home/builder/dev/arduino8475/src/main.ino:167:33: error: no return statement in function returning non-void [-Werror=return-type]
  167 |   saveWeather = SD.open(FN, RW);}        //Open Read at end.  Open at EOF for write/append
      |                                 ^
/home/builder/dev/arduino8475/src/main.ino: In function 'char openFile4(byte, String)':
/home/builder/dev/arduino8475/src/main.ino:173:3: error: no return statement in function returning non-void [-Werror=return-type]
  173 |   }
      |

I suppose that is b/c you are using 'no-warnings' option? Can you retry by either using void as return type for openFile3 and openFile4 or add return with some meaningful value?

Do you mean Tools -->Debug Level: None??? or Exceptions: Disabled???

I did one better and integrated those into the only routine that called them. (The program is 4 programs I cobbled together, so I'm now removing redundancy and such.) The results are the same.

`//SD CARD FUNCTIONS =================================
void openSD() { //Routine to open SD card
S_pln(); S_pln("Open SD card"); //User message
if (!SD.begin(15)) { //If not open, print message.
S_pln("Open SD card failed");
return;}
S_pln("SD Card open");
}

void print2File(String B){ //Write connect data to SD file
SDconFile.close(); //Ensure file status, before re-opening
SDconFile = SD.open(FName2, FILE_WRITE); //Open Read at end. Open at EOF for write/append
if (SDconFile) { //If file there & opened --> write
SDconFile.println(B); //Write to SD
SDconFile.close();} //Close file, flush buffer (reliable but slow)
else {S_pln("Error opening Connect file for write");} //File didn't open
}

void print3File(String B) { //Print data to SD file
saveWeather.close(); //Ensure file status, before re-opening
saveWeather = SD.open(FName3, FILE_WRITE); //Open Read at end. Open at EOF for write/append
if (saveWeather) { //If file there & opened --> write
saveWeather.println(B); //Print string to file
saveWeather.close(); //Close file, flush buffer (reliable but slower)
} else {S_pln("Error opening saveWeather file for write");} //File didn't open
}

char openFile4(byte RW, String FN) { //Open SD FName3 file. char RW. Only 1 at a time.
dataTemp.close(); //Ensure file status, before re-opening
dataTemp = SD.open(FN, RW); //Open Read at end. Open at EOF for write/append
// digitalWrite(LED_BUILTIN, LOW); //D1 Mini: turns LED on. Eject SD if off
}

void print4File(String B) { //Print data to SD file
openFile4(FILE_WRITE,FName4); //Open user SD file for write
if (dataTemp) { //If file there & opened --> write
dataTemp.println(B); //Print string to file
dataTemp.close(); //Close file, flush buffer (reliable but slower)
// digitalWrite(LED_BUILTIN, HIGH); //D1 Mini: turns LED on.Eject SD if off
} else {S_pln("Error opening dataTemp file for write");} //File didn't open
}

void initTempFile(){ //Initialize SD card connect file
SDconFile.close(); //Ensure file is closed
SD.remove(FName4); //Delete connection info file
SDconFile.close(); //Ensure file status, before re-opening
SDconFile = SD.open(FName4, FILE_WRITE); //Open Read at end. Open at EOF for write/append
SDconFile.close(); //Close SD connect file
// server.send(200, "text/html", "Connect Data File Initialized");
}`