OTA upload succesfull, but old sketch remians

[AttilaTtila]

Hi Juraj,

I have 2x Mega2560 (with builtin Wifi) boards and i'd really like to make OTA working for them!
So i burned the Optiboot bootloader by MCUDude.
Then i used your example sketch (SerialWiFiOTA) to test. Then i make minor change in the code and upload it via "Upload using programmer". All seems OK, "Sketch uploaded successfully" message appears, but after board resets, the old sketch started running again (or it just hangs completely).
Any advise please?
Thanks!
Attila

[JAndrassy]

did you use a current version of MegaCore to burn the bootloader?
please turn on verbose mode for Upload in Preferences in IDE and copy the upload command and its the output here

[AttilaTtila]

Yes, MegaCore is freshly downloaded (2.1.3) and bootloader updated after that.

Now, the symptom is that the board hangs after sketch upload and needs a power reset. After the power cycle, the new sketch starts running.

Here's the IDE output:
Using previously compiled file: C:\Users\Attila\AppData\Local\Temp\arduino_build_695308\libraries\ArduinoOTA\ArduinoOTA.a Compiling core... Using precompiled core: C:\Users\Attila\AppData\Local\Temp\arduino_cache_865186\core\core_OTA_boards_avr_mega_8b11847eb7634689bf7b364bdc700700.a Linking everything together... "C:\\Users\\Attila\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-gcc" -Wall -Os -g -flto -fuse-linker-plugin -Wl,--gc-sections -mmcu=atmega2560 -o "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308/OTA_upload_Mega_v0.1.1.ino.elf" "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308\\sketch\\OTA_upload_Mega_v0.1.1.ino.cpp.o" "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308\\libraries\\WiFiEspAT\\WiFi.cpp.o" "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308\\libraries\\WiFiEspAT\\WiFiClient.cpp.o" "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308\\libraries\\WiFiEspAT\\WiFiEspAtBuffManager.cpp.o" "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308\\libraries\\WiFiEspAT\\WiFiEspAtBuffStream.cpp.o" "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308\\libraries\\WiFiEspAT\\WiFiSSLClient.cpp.o" "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308\\libraries\\WiFiEspAT\\WiFiServer.cpp.o" "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308\\libraries\\WiFiEspAT\\WiFiUdp.cpp.o" "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308\\libraries\\WiFiEspAT\\utility\\EspAtDrv.cpp.o" "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308\\libraries\\WiFiEspAT\\utility\\EspAtDrvLogging.cpp.o" "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308\\libraries\\ArduinoOTA\\ArduinoOTA.a" "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308/..\\arduino_cache_865186\\core\\core_OTA_boards_avr_mega_8b11847eb7634689bf7b364bdc700700.a" "-LC:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308" -lm "C:\\Users\\Attila\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-objcopy" -O binary "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308/OTA_upload_Mega_v0.1.1.ino.elf" "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308/OTA_upload_Mega_v0.1.1.ino.bin" "C:\\Users\\Attila\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-objcopy" -O ihex -j .eeprom --set-section-flags=.eeprom=alloc,load --no-change-warnings --change-section-lma .eeprom=0 "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308/OTA_upload_Mega_v0.1.1.ino.elf" "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308/OTA_upload_Mega_v0.1.1.ino.eep" "C:\\Users\\Attila\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-objcopy" -O ihex -R .eeprom "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308/OTA_upload_Mega_v0.1.1.ino.elf" "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308/OTA_upload_Mega_v0.1.1.ino.hex" Using library WiFiEspAT at version 1.3.2 in folder: C:\Arduino\libraries\WiFiEspAT Using library ArduinoOTA at version 1.0.8 in folder: C:\Arduino\libraries\ArduinoOTA "C:\\Users\\Attila\\AppData\\Local\\Arduino15\\packages\\arduino\\tools\\avr-gcc\\7.3.0-atmel3.6.1-arduino7/bin/avr-size" -A "C:\\Users\\Attila\\AppData\\Local\\Temp\\arduino_build_695308/OTA_upload_Mega_v0.1.1.ino.elf" Sketch uses 17878 bytes (6%) of program storage space. Maximum is 261120 bytes. Global variables use 1221 bytes (14%) of dynamic memory, leaving 6971 bytes for local variables. Maximum is 8192 bytes. C:\Users\Attila\AppData\Local\Arduino15\packages\arduino\tools\arduinoOTA\1.3.0/bin/arduinoOTA -address 192.168.2.20 -port 65280 -username arduino -password password -sketch C:\Users\Attila\AppData\Local\Temp\arduino_build_695308/OTA_upload_Mega_v0.1.1.ino.bin -upload /sketch -b Connecting to board ... done Uploading sketch ... done Flashing sketch ... done OK Sketch uploaded successfully

[ChadMatsalla]

I have two Mega 2560 boards. I'm seeing something very similar. First I successfully burn the bootloader.

"/Users/chad/Library/Arduino15/packages/arduino/tools/avrdude/6.3.0-arduino17/bin/avrdude" "-C/Users/chad/Library/Arduino15/packages/arduino/tools/avrdude/6.3.0-arduino17/etc/avrdude.conf" -v -patmega2560 -cstk500v1 -P/dev/cu.usbmodem14101 -b19200 -e -Ulock:w:0x3F:m -Uefuse:w:0xFD:m -Uhfuse:w:0xD6:m -Ulfuse:w:0xFF:m

avrdude: Version 6.3-20190619
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
         Copyright (c) 2007-2014 Joerg Wunsch

         System wide configuration file is "/Users/chad/Library/Arduino15/packages/arduino/tools/avrdude/6.3.0-arduino17/etc/avrdude.conf"
         User configuration file is "/Users/chad/.avrduderc"
         User configuration file does not exist or is not a regular file, skipping

         Using Port                    : /dev/cu.usbmodem14101
         Using Programmer              : stk500v1
         Overriding Baud Rate          : 19200
         AVR Part                      : ATmega2560
         Chip Erase delay              : 9000 us
         PAGEL                         : PD7
         BS2                           : PA0
         RESET disposition             : dedicated
         RETRY pulse                   : SCK
         serial program mode           : yes
         parallel program mode         : yes
         Timeout                       : 200
         StabDelay                     : 100
         CmdexeDelay                   : 25
         SyncLoops                     : 32
         ByteDelay                     : 0
         PollIndex                     : 3
         PollValue                     : 0x53
         Memory Detail                 :

                                  Block Poll               Page                       Polled
           Memory Type Mode Delay Size  Indx Paged  Size   Size #Pages MinW  MaxW   ReadBack
           ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
           eeprom        65    10     8    0 no       4096    8      0  9000  9000 0x00 0x00
           flash         65    10   256    0 yes    262144  256   1024  4500  4500 0x00 0x00
           lfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           hfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           efuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           lock           0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           calibration    0     0     0    0 no          1    0      0     0     0 0x00 0x00
           signature      0     0     0    0 no          3    0      0     0     0 0x00 0x00

         Programmer Type : STK500
         Description     : Atmel STK500 Version 1.x firmware
         Hardware Version: 2
         Firmware Version: 1.18
         Topcard         : Unknown
         Vtarget         : 0.0 V
         Varef           : 0.0 V
         Oscillator      : Off
         SCK period      : 0.1 us

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.03s

avrdude: Device signature = 0x1e9801 (probably m2560)
avrdude: erasing chip
avrdude: reading input file "0x3F"
avrdude: writing lock (1 bytes):

Writing | ################################################## | 100% 0.01s

avrdude: 1 bytes of lock written
avrdude: verifying lock memory against 0x3F:
avrdude: load data lock data from input file 0x3F:
avrdude: input file 0x3F contains 1 bytes
avrdude: reading on-chip lock data:

Reading | ################################################## | 100% 0.01s

avrdude: verifying ...
avrdude: 1 bytes of lock verified
avrdude: reading input file "0xFD"
avrdude: writing efuse (1 bytes):

Writing | ################################################## | 100% 0.01s

avrdude: 1 bytes of efuse written
avrdude: verifying efuse memory against 0xFD:
avrdude: load data efuse data from input file 0xFD:
avrdude: input file 0xFD contains 1 bytes
avrdude: reading on-chip efuse data:

Reading | ################################################## | 100% 0.01s

avrdude: verifying ...
avrdude: 1 bytes of efuse verified
avrdude: reading input file "0xD6"
avrdude: writing hfuse (1 bytes):

Writing | ################################################## | 100% 0.01s

avrdude: 1 bytes of hfuse written
avrdude: verifying hfuse memory against 0xD6:
avrdude: load data hfuse data from input file 0xD6:
avrdude: input file 0xD6 contains 1 bytes
avrdude: reading on-chip hfuse data:

Reading | ################################################## | 100% 0.01s

avrdude: verifying ...
avrdude: 1 bytes of hfuse verified
avrdude: reading input file "0xFF"
avrdude: writing lfuse (1 bytes):

Writing | ################################################## | 100% 0.01s

avrdude: 1 bytes of lfuse written
avrdude: verifying lfuse memory against 0xFF:
avrdude: load data lfuse data from input file 0xFF:
avrdude: input file 0xFF contains 1 bytes
avrdude: reading on-chip lfuse data:

Reading | "/Users/chad/Library/Arduino15/packages/arduino/tools/avrdude/6.3.0-arduino17/bin/avrdude" "-C/Users/chad/Library/Arduino15/packages/arduino/tools/avrdude/6.3.0-arduino17/etc/avrdude.conf" -v -patmega2560 -cstk500v1 -P/dev/cu.usbmodem14101 -b19200 "-Uflash:w:/Users/chad/git-controlled/arduino/hardware/csm/avr/bootloaders/optiboot8/optiboot_atmega2560.hex:i" -Ulock:w:0x0F:m
################################################## | 100% 0.01s

avrdude: verifying ...
avrdude: 1 bytes of lfuse verified

avrdude done.  Thank you.


avrdude: Version 6.3-20190619
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
         Copyright (c) 2007-2014 Joerg Wunsch

         System wide configuration file is "/Users/chad/Library/Arduino15/packages/arduino/tools/avrdude/6.3.0-arduino17/etc/avrdude.conf"
         User configuration file is "/Users/chad/.avrduderc"
         User configuration file does not exist or is not a regular file, skipping

         Using Port                    : /dev/cu.usbmodem14101
         Using Programmer              : stk500v1
         Overriding Baud Rate          : 19200
         AVR Part                      : ATmega2560
         Chip Erase delay              : 9000 us
         PAGEL                         : PD7
         BS2                           : PA0
         RESET disposition             : dedicated
         RETRY pulse                   : SCK
         serial program mode           : yes
         parallel program mode         : yes
         Timeout                       : 200
         StabDelay                     : 100
         CmdexeDelay                   : 25
         SyncLoops                     : 32
         ByteDelay                     : 0
         PollIndex                     : 3
         PollValue                     : 0x53
         Memory Detail                 :

                                  Block Poll               Page                       Polled
           Memory Type Mode Delay Size  Indx Paged  Size   Size #Pages MinW  MaxW   ReadBack
           ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
           eeprom        65    10     8    0 no       4096    8      0  9000  9000 0x00 0x00
           flash         65    10   256    0 yes    262144  256   1024  4500  4500 0x00 0x00
           lfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           hfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           efuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           lock           0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           calibration    0     0     0    0 no          1    0      0     0     0 0x00 0x00
           signature      0     0     0    0 no          3    0      0     0     0 0x00 0x00

         Programmer Type : STK500
         Description     : Atmel STK500 Version 1.x firmware
         Hardware Version: 2
         Firmware Version: 1.18
         Topcard         : Unknown
         Vtarget         : 0.0 V
         Varef           : 0.0 V
         Oscillator      : Off
         SCK period      : 0.1 us

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.03s

avrdude: Device signature = 0x1e9801 (probably m2560)
avrdude: NOTE: "flash" memory has been specified, an erase cycle will be performed
         To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: reading input file "/Users/chad/git-controlled/arduino/hardware/csm/avr/bootloaders/optiboot8/optiboot_atmega2560.hex"
avrdude: writing flash (262144 bytes):

Writing | ################################################## | 100% 0.00s

avrdude: 262144 bytes of flash written
avrdude: verifying flash memory against /Users/chad/git-controlled/arduino/hardware/csm/avr/bootloaders/optiboot8/optiboot_atmega2560.hex:
avrdude: load data flash data from input file /Users/chad/git-controlled/arduino/hardware/csm/avr/bootloaders/optiboot8/optiboot_atmega2560.hex:
avrdude: input file /Users/chad/git-controlled/arduino/hardware/csm/avr/bootloaders/optiboot8/optiboot_atmega2560.hex contains 262144 bytes
avrdude: reading on-chip flash data:

Reading | ################################################## | 100% 0.00s

avrdude: verifying ...
avrdude: 262144 bytes of flash verified
avrdude: reading input file "0x0F"
avrdude: writing lock (1 bytes):

Writing | ################################################## | 100% 0.02s

avrdude: 1 bytes of lock written
avrdude: verifying lock memory against 0x0F:
avrdude: load data lock data from input file 0x0F:
avrdude: input file 0x0F contains 1 bytes
avrdude: reading on-chip lock data:

Reading | ################################################## | 100% 0.01s

avrdude: verifying ...
avrdude: 1 bytes of lock verified

avrdude done.  Thank you.

I unplug the target from the programmer. I plug USB into the target. I flash, in this case, ATmega_SD.ino

/Users/chad/Library/Arduino15/packages/arduino/tools/avr-gcc/7.3.0-atmel3.6.1-arduino7/bin/avr-objcopy -O ihex -j .eeprom --set-section-flags=.eeprom=alloc,load --no-change-warnings --change-section-lma .eeprom=0 /private/var/folders/xp/5lxl6k0x53lcbnc9_6gj0ty80000gt/T/arduino/sketches/3A3B61CFE14007AF3FA9C402169BCAAD/ATmega_SD.ino.elf /private/var/folders/xp/5lxl6k0x53lcbnc9_6gj0ty80000gt/T/arduino/sketches/3A3B61CFE14007AF3FA9C402169BCAAD/ATmega_SD.ino.eep
/Users/chad/Library/Arduino15/packages/arduino/tools/avr-gcc/7.3.0-atmel3.6.1-arduino7/bin/avr-objcopy -O ihex -R .eeprom /private/var/folders/xp/5lxl6k0x53lcbnc9_6gj0ty80000gt/T/arduino/sketches/3A3B61CFE14007AF3FA9C402169BCAAD/ATmega_SD.ino.elf /private/var/folders/xp/5lxl6k0x53lcbnc9_6gj0ty80000gt/T/arduino/sketches/3A3B61CFE14007AF3FA9C402169BCAAD/ATmega_SD.ino.hex

Using library SPI at version 1.0 in folder: /Users/chad/Library/Arduino15/packages/arduino/hardware/avr/1.8.6/libraries/SPI 
Using library SD at version 1.2.4 in folder: /Users/chad/git-controlled/arduino/libraries/SD 
Using library Ethernet at version 2.0.2 in folder: /Users/chad/git-controlled/arduino/libraries/Ethernet 
Using library ArduinoOTA at version 1.0.9 in folder: /Users/chad/git-controlled/arduino/libraries/ArduinoOTA 
/Users/chad/Library/Arduino15/packages/arduino/tools/avr-gcc/7.3.0-atmel3.6.1-arduino7/bin/avr-size -A /private/var/folders/xp/5lxl6k0x53lcbnc9_6gj0ty80000gt/T/arduino/sketches/3A3B61CFE14007AF3FA9C402169BCAAD/ATmega_SD.ino.elf
Sketch uses 31130 bytes (11%) of program storage space. Maximum is 261120 bytes.
Global variables use 1982 bytes (24%) of dynamic memory, leaving 6210 bytes for local variables. Maximum is 8192 bytes.
"/Users/chad/Library/Arduino15/packages/arduino/tools/avrdude/6.3.0-arduino17/bin/avrdude" "-C/Users/chad/Library/Arduino15/packages/arduino/tools/avrdude/6.3.0-arduino17/etc/avrdude.conf" -v -V -patmega2560 -carduino "-P/dev/cu.usbmodem14101" -b115200 -D "-Uflash:w:/private/var/folders/xp/5lxl6k0x53lcbnc9_6gj0ty80000gt/T/arduino/sketches/3A3B61CFE14007AF3FA9C402169BCAAD/ATmega_SD.ino.hex:i"

avrdude: Version 6.3-20190619
         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
         Copyright (c) 2007-2014 Joerg Wunsch

         System wide configuration file is "/Users/chad/Library/Arduino15/packages/arduino/tools/avrdude/6.3.0-arduino17/etc/avrdude.conf"
         User configuration file is "/Users/chad/.avrduderc"
         User configuration file does not exist or is not a regular file, skipping

         Using Port                    : /dev/cu.usbmodem14101
         Using Programmer              : arduino
         Overriding Baud Rate          : 115200
         AVR Part                      : ATmega2560
         Chip Erase delay              : 9000 us
         PAGEL                         : PD7
         BS2                           : PA0
         RESET disposition             : dedicated
         RETRY pulse                   : SCK
         serial program mode           : yes
         parallel program mode         : yes
         Timeout                       : 200
         StabDelay                     : 100
         CmdexeDelay                   : 25
         SyncLoops                     : 32
         ByteDelay                     : 0
         PollIndex                     : 3
         PollValue                     : 0x53
         Memory Detail                 :

                                  Block Poll               Page                       Polled
           Memory Type Mode Delay Size  Indx Paged  Size   Size #Pages MinW  MaxW   ReadBack
           ----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
           eeprom        65    10     8    0 no       4096    8      0  9000  9000 0x00 0x00
           flash         65    10   256    0 yes    262144  256   1024  4500  4500 0x00 0x00
           lfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           hfuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           efuse          0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           lock           0     0     0    0 no          1    0      0  9000  9000 0x00 0x00
           calibration    0     0     0    0 no          1    0      0     0     0 0x00 0x00
           signature      0     0     0    0 no          3    0      0     0     0 0x00 0x00

         Programmer Type : Arduino
         Description     : Arduino
         Hardware Version: 3
         Firmware Version: 8.0
         Vtarget         : 0.3 V
         Varef           : 0.3 V
         Oscillator      : 28.800 kHz
         SCK period      : 3.3 us

avrdude: AVR device initialized and ready to accept instructions

Reading | ################################################## | 100% 0.00s

avrdude: Device signature = 0x1e9801 (probably m2560)
avrdude: reading input file "/private/var/folders/xp/5lxl6k0x53lcbnc9_6gj0ty80000gt/T/arduino/sketches/3A3B61CFE14007AF3FA9C402169BCAAD/ATmega_SD.ino.hex"
avrdude: writing flash (31130 bytes):

Writing | ################################################## | 100% 4.50s

avrdude: 31130 bytes of flash written

avrdude done.  Thank you.

I check the output from Serial and see the date and time that I put on line 44. I change the date and time that I put on line 44 and flash OTA:

/home/chad/.arduino15/packages/arduino/tools/avr-gcc/7.3.0-atmel3.6.1-arduino7/bin/avr-gcc -w -Os -g -flto -fuse-linker-plugin -Wl,--gc-sections -mmcu=atmega2560 -o /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/OTEthernet.ino.elf /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/sketch/OTEthernet.ino.cpp.o /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/libraries/SPI/SPI.cpp.o /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/libraries/Ethernet/Dhcp.cpp.o /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/libraries/Ethernet/Dns.cpp.o /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/libraries/Ethernet/Ethernet.cpp.o /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/libraries/Ethernet/EthernetClient.cpp.o /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/libraries/Ethernet/EthernetServer.cpp.o /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/libraries/Ethernet/EthernetUdp.cpp.o /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/libraries/Ethernet/socket.cpp.o /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/libraries/Ethernet/utility/w5100.cpp.o /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/libraries/ArduinoOTA/ArduinoOTA.a /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/../../cores/csm_avr_mega_61a07c4146d734bc36057eec6ed56cc7/core.a -L/tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B -lm
/home/chad/.arduino15/packages/arduino/tools/avr-gcc/7.3.0-atmel3.6.1-arduino7/bin/avr-objcopy -O binary /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/OTEthernet.ino.elf /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/OTEthernet.ino.bin
/home/chad/.arduino15/packages/arduino/tools/avr-gcc/7.3.0-atmel3.6.1-arduino7/bin/avr-objcopy -O ihex -j .eeprom --set-section-flags=.eeprom=alloc,load --no-change-warnings --change-section-lma .eeprom=0 /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/OTEthernet.ino.elf /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/OTEthernet.ino.eep
/home/chad/.arduino15/packages/arduino/tools/avr-gcc/7.3.0-atmel3.6.1-arduino7/bin/avr-objcopy -O ihex -R .eeprom /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/OTEthernet.ino.elf /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/OTEthernet.ino.hex

Using library SPI at version 1.0 in folder: /home/chad/.arduino15/packages/arduino/hardware/avr/1.8.6/libraries/SPI 
Using library Ethernet at version 2.0.2 in folder: /home/chad/.arduino15/libraries/Ethernet 
Using library ArduinoOTA at version 1.0.9 in folder: /home/chad/Arduino/libraries/ArduinoOTA 
/home/chad/.arduino15/packages/arduino/tools/avr-gcc/7.3.0-atmel3.6.1-arduino7/bin/avr-size -A /tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/OTEthernet.ino.elf
Sketch uses 22420 bytes (8%) of program storage space. Maximum is 261120 bytes.
Global variables use 1246 bytes (15%) of dynamic memory, leaving 6946 bytes for local variables. Maximum is 8192 bytes.
"/home/chad/.arduino15/packages/arduino/tools/arduinoOTA/1.3.0/bin/arduinoOTA" -address 192.168.0.104 -port 65280 -username arduino -password "diesel" -sketch "/tmp/arduino/sketches/9FD7EA2166AD2CCB7728100A8E24780B/OTEthernet.ino.bin" -upload /sketch -b
Connecting to board ...  done
Uploading sketch ...  done
Flashing sketch ...  done
OK
Sketch uploaded successfully

Check the Serial output from the target. The sketch has not changed.

[ChadMatsalla]

Does flashing the first sketch over USB somehow replace the bootloader with the original, non-optiboot bootloader? How would I detect that? Should the first sketch be flashed onto the Mega in a way other than USB?