error: 'pgm_read_ptr' was not declared in this scope

[Talkwondo]

Hello,
I am trying to work with arduino cure due and get this weird error:

there are no arguments to 'pgm_read_ptr' that depend on a template parameter, so a declaration of 'pgm_read_ptr' must be available [-fpermissive]

return reinterpret_cast(pgm_read_ptr(p));
in the gmspace_generic.hpp

also,
error: 'pgm_read_ptr' was not declared in this scope

how to fix it?

thanks,

[bblanchon]

Hi @Talkwondo,

You can fix this error by defining ARDUINOJSON_ENABLE_PROGMEM to 0.

However, this error shouldn't happen in the first place.
This most likely comes from a missing macro in Arduino's headers.
What Arduino Core are you using?

Best Regards,
Benoit

[Talkwondo]

I had a problem with the arduino core now i get the famous problem:
reinterpret_cast(pgm_read_ptr(p))
'const void*' is not a pointer-to-object type

[bblanchon]

'const void*' is not a pointer-to-object type

This is arduino/ArduinoCore-API#118

Which Arduino Core are you using? (what hardware if you prefer)