Help with backing up EmonTx firmware

Please verify that I have downloaded my firmware and can upload it again if I need to revert my changes.

I connected my EmonTx v3.4 to a Raspberry Pi on which I had installed avrdude (sudo apt-get install -y avrdude).

I ran the following command:

avrdude -v -p atmega328p -c arduino -b 115200 -P /dev/ttyUSB0 -U flash:r:emontx_backup.hex:i

And I want to make sure I will be able to put it back in with a command like:

avrdude -v -p atmega328p -c arduino -b 115200 -P /dev/ttyUSB0 -U flash:w:emontx_backup.hex

The output I got was as follows:

avrdude: Version 6.1, compiled on Jul  7 2015 at 10:29:47

         Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/

         Copyright (c) 2007-2014 Joerg Wunsch


         System wide configuration file is "/etc/avrdude.conf"

         User configuration file is "/home/pi/.avrduderc"

         User configuration file does not exist or is not a regular file, skipping


         Using Port                    : /dev/ttyUSB0

         Using Programmer              : arduino

         Overriding Baud Rate          : 115200

         AVR Part                      : ATmega328P

         Chip Erase delay              : 9000 us

         PAGEL                         : PD7

         BS2                           : PC2

         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    20     4    0 no       1024    4      0  3600  3600 0xff 0xff

           flash         65     6   128    0 yes     32768  128    256  4500  4500 0xff 0xff

           lfuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00

           hfuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00

           efuse          0     0     0    0 no          1    0      0  4500  4500 0x00 0x00

           lock           0     0     0    0 no          1    0      0  4500  4500 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: 4.4

         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 = 0x1e950f

avrdude: safemode: lfuse reads as 0

avrdude: safemode: hfuse reads as 0

avrdude: safemode: efuse reads as 0

avrdude: reading flash memory:


Reading | ################################################## | 100% 3.67s


avrdude: writing output file "emontx_backup.hex"


avrdude: safemode: lfuse reads as 0

avrdude: safemode: hfuse reads as 0

avrdude: safemode: efuse reads as 0

avrdude: safemode: Fuses OK (E:00, H:00, L:00)


avrdude done.  Thank you.