compilation error for board lolin32 + oled

[twanek]

hi!

i try to use this board: https://www.aliexpress.com/item/Wemos-18650-Battery-shield-V3-RaspberryPi-Arduino-Lolin-ESP32-OLED-wemos-for-Arduino-ESP32S-WiFi-Modules/32807898232.html

with this lib, but i've got a compile error:

In file included from C:\ARDUINO\libraries\esp8266-oled-ssd1306/SSD1306Wire.h:31:0,

                 from C:\ARDUINO\libraries\esp8266-oled-ssd1306/SSD1306.h:30,

                 from C:\Users\wanek\AppData\Local\Temp\arduino_modified_sketch_891573\SSD1306SimpleDemo.ino:29:

C:\ARDUINO\libraries\esp8266-oled-ssd1306/OLEDDisplay.h: In member function 'virtual bool OLEDDisplay::connect()':

C:\ARDUINO\libraries\esp8266-oled-ssd1306/OLEDDisplay.h:253:29: error: no return statement in function returning non-void [-Werror=return-type]

     virtual bool connect() {};

                             ^

In file included from C:\ARDUINO\libraries\esp8266-oled-ssd1306/SSD1306.h:30:0,

                 from C:\Users\wanek\AppData\Local\Temp\arduino_modified_sketch_891573\SSD1306SimpleDemo.ino:29:

C:\ARDUINO\libraries\esp8266-oled-ssd1306/SSD1306Wire.h: In member function 'virtual void SSD1306Wire::display()':

C:\ARDUINO\libraries\esp8266-oled-ssd1306/SSD1306Wire.h:83:23: warning: comparison is always false due to limited range of data type [-Wtype-limits]

         if (minBoundY == ~0) return;

                       ^

cc1plus.exe: some warnings being treated as errors

Using library Wire at version 1.0 in folder: C:\ARDUINO\hardware\espressif\esp32\libraries\Wire 
Using library esp8266-oled-ssd1306 at version 3.2.7 in folder: C:\ARDUINO\libraries\esp8266-oled-ssd1306 
exit status 1
Error compiling for board WEMOS LOLIN32.

the only thing i modified in the SSD1306SimpleDemo example is at line 61 replaced D3, D5 with 5, 4 as per seller instruction.

thanks!

[twanek]

ok, after some testing, i figured out, that the example code on the aliexpress site was given for the esp8266 version of this board, not esp32. they say replace "D3" with "5" and "D5" with "4". (if i set in arduino ide board type esp8266, it compiles fine, but if i set esp32 it gives the compilation error)

so, the question is, what should i use instead of D3 and D5 with the esp32 board? (for i2c)

[schumar]

The pin numbers given by the vendor are correct.

I guess the issue is a newer version of gcc, which is a bit more strict regarding "clean" code. Please try File -> Preferences -> Compiler warnings: Default

[twanek]

thanks for the advice, it compiles now! (i do not have access right now to the hw to upload / test, but i think should be ok.

the solution is interesting for me, because i never thought that the compiler warnings in the preferences are actually modify the compilation end process... i thought that, it influences only the message output in the window.

[beosro]

Hi. Well, I have the same problem with ESP32 and Oled (Heltec board). Same warning and error. The solution with "Default" Compiler warnings works perfectly! Thanks schumar! Alex

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.