ESP8266, pgm_read_ptr(): error: 'const void*' is not a pointer-to-object type

[phil31]

Hello all,

new with Arduino design, i'm trying to do some stufs with this librarie !
i try to compile the samples for Mega2560 or ESP32, that works (at least, compilation is right !)
but as soon as i change the target to ESP8266 generic (or ESP8285 generic which is my final target), with the same sample, i'v got some compilation errors that i can't solve by myself (newbie ...)

here it it the logs :

In file included from D:\Arduino\libraries\ArduinoJson\src/ArduinoJson/Polyfills/static_array.hpp:11:0,
from D:\Arduino\libraries\ArduinoJson\src/ArduinoJson/Numbers/FloatTraits.hpp:14,
from D:\Arduino\libraries\ArduinoJson\src/ArduinoJson/Numbers/convertNumber.hpp:18,
from D:\Arduino\libraries\ArduinoJson\src/ArduinoJson/Variant/VariantData.hpp:9,
from D:\Arduino\libraries\ArduinoJson\src/ArduinoJson/Variant/SlotFunctions.hpp:8,
from D:\Arduino\libraries\ArduinoJson\src/ArduinoJson/Array/ArrayIterator.hpp:7,
from D:\Arduino\libraries\ArduinoJson\src/ArduinoJson/Array/ArrayRef.hpp:8,
from D:\Arduino\libraries\ArduinoJson\src/ArduinoJson.hpp:17,
from D:\Arduino\libraries\ArduinoJson\src/ArduinoJson.h:9,
from D:\Arduino\WP-FP\WP-FP.ino:48:
D:\Arduino\libraries\ArduinoJson\src/ArduinoJson/Polyfills/pgmspace_generic.hpp: In instantiation of 'typename ArduinoJson6172_91::enable_if<ArduinoJson6172_91::is_pointer::value, T>::type ArduinoJson6172_91::pgm_read(const void*) [with T = const __FlashStringHelper*; typename ArduinoJson6172_91::enable_if<ArduinoJson6172_91::is_pointer::value, T>::type = const __FlashStringHelper*]':
D:\Arduino\libraries\ArduinoJson\src/ArduinoJson/Deserialization/DeserializationError.hpp:103:12: required from here
D:\Arduino\libraries\ArduinoJson\src/ArduinoJson/Polyfills/pgmspace_generic.hpp:14:45: error: 'const void*' is not a pointer-to-object type
return reinterpret_cast(pgm_read_ptr(p));
^
exit status 1
Error compiling for board Generic ESP8285 Module.

may i get some tips or info to solve this please ?
Arduino 1.8.13 with ArduinoJson 6.17.2

thanks, regards

[bblanchon]

Hi @phil31,

Thank you for reporting this problem.

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

This is the same error we encountered in #1381.
It was caused by a bug in Arduino Core API and was fixed by arduino/ArduinoCore-API#118 in October.

What surprises me most is that you shouldn't be affected by this bug because the ESP8266 core for Arduino is not based on Arduino Core API. And also, we can see that their definition is correct.

Are you using an alternative core for ESP8266?
If so, please open an issue and tell them about arduino/ArduinoCore-API#118.

Best regards,
Benoit

[phil31]

Hi Benoit

thanks for your fast reply.
what do you mean by "alternative core for ESP8266" ? .. i dont know, i just install Arduino IDE 1.8.13 and all required from the IDE.
i can perfectly compile my program when i comment the "include <ArduinoJson.h> ".

i can perfectly compile the examples when the target are others than ESP8266 or ESO8285 (wich is my final target).
can you compile the samples for Generic ESP8266 ?

regards
Phil

[bblanchon]

Hi Phil,

As far as I know, the Arduino IDE 1.8.13 doesn't support ESP8266 natively.
To program an ESP8266 with the Arduino IDE, you must install an additional toolkit.
As an example, see the installation instructions for the ESP8266 core for Arduino.

Of course, the examples compile with ESP8266; they are even part of the Continuous Integration.
Also, if they didn't, I would receive a massive amount of complaints. 😄

I suggest you upgrade or reinstall the ESP8266 core for Arduino.
If that's still not working, you can disable support for PROGMEM until we figure what's wrong (see ARDUINOJSON_ENABLE_PROGMEM).

Best regards,
Benoit

[phil31]

no upgrade available, wii lty uninstall/reinstall IDE and core

regards

[bblanchon]

Please let me know if it fixed the problem.

[phil31]

well i just try to compile the samples for ESP targets, on another computer with a fresh install.
the compilation is working as expected !

i dont know how to remove properly the ESP core from arduino to try a new install ?

regards

[bblanchon]

To do a fresh install, you may need to delete the folder %LOCALAPPDATA%\Arduino15, that's where the cores are installed.