.hex file not getting generated

I’m trying to get .hex file from my code but it’s only giving me .bin and .elf files when i build it. I need .hex file to try my code on wokwi extension.
PlatfromIO is already in latest version and I’ve tried Cleaning and Building again and again but it’s not working at all.

Here’s my platform.ini file :-
platform = ststm32
board = genericSTM32F103RC
framework = arduino
lib_deps = mbed-sergunb/main@0.0.0+sha.21b85706ec2f
build_flags = -fformat=ihex

Anyone have any idea how so solve this problem ? Any help is much appreciated.

The builder script does not build trigger the hex file generation anymore. You have to register a post-action on the generated ELF file that will generate the HEX file. See “Custom HEX from ELF” in


Thanks for your reply sir but i don’t think i quite get what you mean. Sorry but can you please elaborate what you mean please ?

I really appreciate your response sir.

In your platformio.ini, add

extra_scripts = post:extra_script.py

At the same directory level as the platformio.ini, create a new extra_script.py file and fill it with the content

# Custom HEX from ELF
    env.VerboseAction(" ".join([
        "$OBJCOPY", "-O", "ihex", "-R", ".eeprom",
        "$BUILD_DIR/${PROGNAME}.elf", "$BUILD_DIR/${PROGNAME}.hex"
    ]), "Building $BUILD_DIR/${PROGNAME}.hex")

After a new clean build (project task → Clean, Build), the .pio/build/<env> folder should have firmware.hex.

1 Like

i have the same problem,

Here’s my platform.ini file :-

platform = espressif8266
board = nodemcuv2
framework = arduino
extra_scripts = post:extra_script.py

extra_script.py content :

# Custom HEX from ELF
    env.VerboseAction(" ".join([
        "$OBJCOPY", "-O", "ihex", "-R", ".eeprom",
        "$BUILD_DIR/${PROGNAME}.elf", "$BUILD_DIR/${PROGNAME}.hex"
    ]), "Building $BUILD_DIR/${PROGNAME}.hex")

but i get error :

Building C:\Users\Kavi\Downloads\Sem 6\IP\dimmer\.pio\build\nodemcuv3/firmware.hex
Usage: xtensa-lx106-elf-objcopy [option(s)] in-file [out-file]
 Copies a binary file, possibly transforming it in the process
 The options are:
  -I --input-target <bfdname>      Assume input file is in format <bfdname>
  -O --output-target <bfdname>     Create an output file in format <bfdname>
  -B --binary-architecture <arch>  Set output arch, when input is arch-less
  -F --target <bfdname>            Set both input and output format to <bfdname>
     --debugging                   Convert debugging information, if possible
  -p --preserve-dates              Copy modified/access timestamps to the output
  -D --enable-deterministic-archives
                                   Produce deterministic output when stripping archives
  -U --disable-deterministic-archives
                                   Disable -D behavior (default)
  -j --only-section <name>         Only copy section <name> into the output
     --add-gnu-debuglink=<file>    Add section .gnu_debuglink linking to <file>
  -R --remove-section <name>       Remove section <name> from the output
     --remove-relocations <name>   Remove relocations from section <name>
  -S --strip-all                   Remove all symbol and relocation information
  -g --strip-debug                 Remove all debugging symbols & sections
     --strip-dwo                   Remove all DWO sections
     --strip-unneeded              Remove all symbols not needed by relocations
  -N --strip-symbol <name>         Do not copy symbol <name>
     --strip-unneeded-symbol <name>
                                   Do not copy symbol <name> unless needed by
     --only-keep-debug             Strip everything but the debug information
     --extract-dwo                 Copy only DWO sections
     --extract-symbol              Remove section contents but keep symbols
  -K --keep-symbol <name>          Do not strip symbol <name>
     --keep-file-symbols           Do not strip file symbol(s)
     --localize-hidden             Turn all ELF hidden symbols into locals
  -L --localize-symbol <name>      Force symbol <name> to be marked as a local
     --globalize-symbol <name>     Force symbol <name> to be marked as a global
  -G --keep-global-symbol <name>   Localize all symbols except <name>
  -W --weaken-symbol <name>        Force symbol <name> to be marked as a weak
     --weaken                      Force all global symbols to be marked as weak
  -w --wildcard                    Permit wildcard in symbol comparison
  -x --discard-all                 Remove all non-global symbols
  -X --discard-locals              Remove any compiler-generated symbols
  -i --interleave[=<number>]       Only copy N out of every <number> bytes
     --interleave-width <number>   Set N for --interleave
  -b --byte <num>                  Select byte <num> in every interleaved block
     --gap-fill <val>              Fill gaps between sections with <val>
     --pad-to <addr>               Pad the last section up to address <addr>
     --set-start <addr>            Set the start address to <addr>
    {--change-start|--adjust-start} <incr>
                                   Add <incr> to the start address
    {--change-addresses|--adjust-vma} <incr>
                                   Add <incr> to LMA, VMA and start addresses
    {--change-section-address|--adjust-section-vma} <name>{=|+|-}<val>
                                   Change LMA and VMA of section <name> by <val>
     --change-section-lma <name>{=|+|-}<val>
                                   Change the LMA of section <name> by <val>
     --change-section-vma <name>{=|+|-}<val>
                                   Change the VMA of section <name> by <val>
                                   Warn if a named section does not exist
     --set-section-flags <name>=<flags>
                                   Set section <name>'s properties to <flags>
     --add-section <name>=<file>   Add section <name> found in <file> to output
     --update-section <name>=<file>
                                   Update contents of section <name> with
                                   contents found in <file>
     --dump-section <name>=<file>  Dump the contents of section <name> into <file>
     --rename-section <old>=<new>[,<flags>] Rename section <old> to <new>
     --long-section-names {enable|disable|keep}
                                   Handle long section names in Coff objects.
     --change-leading-char         Force output format's leading character style
     --remove-leading-char         Remove leading character from global symbols
     --reverse-bytes=<num>         Reverse <num> bytes at a time, in output sections with content
     --redefine-sym <old>=<new>    Redefine symbol name <old> to <new>
     --redefine-syms <file>        --redefine-sym for all symbol pairs
                                     listed in <file>
     --srec-len <number>           Restrict the length of generated Srecords
     --srec-forceS3                Restrict the type of generated Srecords to S3
     --strip-symbols <file>        -N for all symbols listed in <file>
     --strip-unneeded-symbols <file>
                                   --strip-unneeded-symbol for all symbols listed
                                     in <file>
     --keep-symbols <file>         -K for all symbols listed in <file>
     --localize-symbols <file>     -L for all symbols listed in <file>
     --globalize-symbols <file>    --globalize-symbol for all in <file>
     --keep-global-symbols <file>  -G for all symbols listed in <file>
     --weaken-symbols <file>       -W for all symbols listed in <file>
     --add-symbol <name>=[<section>:]<value>[,<flags>]  Add a symbol
     --alt-machine-code <index>    Use the target's <index>'th alternative machine
     --writable-text               Mark the output text as writable
     --readonly-text               Make the output text write protected
     --pure                        Mark the output file as demand paged
     --impure                      Mark the output file as impure
     --prefix-symbols <prefix>     Add <prefix> to start of every symbol name
     --prefix-sections <prefix>    Add <prefix> to start of every section name
     --prefix-alloc-sections <prefix>
                                   Add <prefix> to start of every allocatable
                                     section name
     --file-alignment <num>        Set PE file alignment to <num>
     --heap <reserve>[,<commit>]   Set PE reserve/commit heap to <reserve>/
     --image-base <address>        Set PE image base to <address>
     --section-alignment <num>     Set PE section alignment to <num>
     --stack <reserve>[,<commit>]  Set PE reserve/commit stack to <reserve>/
     --subsystem <name>[:<version>]
                                   Set PE subsystem to <name> [& <version>]
                                   Compress DWARF debug sections using zlib
     --decompress-debug-sections   Decompress DWARF debug sections using zlib
     --elf-stt-common=[yes|no]     Generate ELF common symbols with STT_COMMON
  -M  --merge-notes                Remove redundant entries in note sections
      --no-merge-notes             Do not attempt to remove redundant notes (default)
  -v --verbose                     List all object files modified
  @<file>                          Read options from <file>
  -V --version                     Display this program's version number
  -h --help                        Display this output
     --info                        List object formats & architectures supported
xtensa-lx106-elf-objcopy: supported targets: elf32-xtensa-le elf32-xtensa-be elf32-little elf32-big plugin srec symbolsrec verilog tekhex binary ihex
*** [.pio\build\nodemcuv3\firmware.elf] Error 1

Your answer Fixed my issue. The info on the PIO page link below didnt help but you did. I thank you friend!!!


I am also trying to generate the .hex file. But when I put the python code it shows some error like “env is not defined” and “Import is not defined”.
Screenshot 2024-04-25 180047

I am using Ubuntu 22.04.

Ignore intellisense errors in extra_scripts. The Intellisense has no idea about the objects provide by the SCons frameworks during runtime.