Receiving multiple definition build error when using SSD1306 driver

[CKohl.3]

I'm new to STM32 and my C skills are very rusty

I'm trying to create a simple program to demo the usage of an Adafruit SSD1306 SPI OLED board

In my main.c I need to #include "ssd1306.h" from this driver because I need some of the definitions.

The problem is that I'm receiving a bunch of multiple definition errors. For example:

multiple definition of `HAL_EXTI_ClearConfigLine'; ./Drivers/STM32F0xx_HAL_Driver/Src/stm32f0xx_hal_exti 3.o:/Users/chrisk/Documents/STM32CubeIDE/workspace_1.11.0/STM32_AdafruitSSD1306_128x32_Example/Debug/../Drivers/STM32F0xx_HAL_Driver/Src/stm32f0xx_hal_exti 3.c:318: first defined here	stm32f0xx_hal_exti.c	/STM32_AdafruitSSD1306_128x32_Example/Drivers/STM32F0xx_HAL_Driver/Src	line 318	C/C++ Problem
multiple definition of `HAL_EXTI_ClearPending'; ./Drivers/STM32F0xx_HAL_Driver/Src/stm32f0xx_hal_exti 3.o:/Users/chrisk/Documents/STM32CubeIDE/workspace_1.11.0/STM32_AdafruitSSD1306_128x32_Example/Debug/../Drivers/STM32F0xx_HAL_Driver/Src/stm32f0xx_hal_exti 3.c:497: first defined here	stm32f0xx_hal_exti.c	/STM32_AdafruitSSD1306_128x32_Example/Drivers/STM32F0xx_HAL_Driver/Src	line 497	C/C++ Problem
multiple definition of `HAL_EXTI_GenerateSWI'; ./Drivers/STM32F0xx_HAL_Driver/Src/stm32f0xx_hal_exti 3.o:/Users/chrisk/Documents/STM32CubeIDE/workspace_1.11.0/STM32_AdafruitSSD1306_128x32_Example/Debug/../Drivers/STM32F0xx_HAL_Driver/Src/stm32f0xx_hal_exti 3.c:518: first defined here	stm32f0xx_hal_exti.c	/STM32_AdafruitSSD1306_128x32_Example/Drivers/STM32F0xx_HAL_Driver/Src	line 518	C/C++ Problem

If I remove the #include "ssd1306.h" line that problem goes away, but I need the definitions so this isn't a viable solution.

My best guess is that ssd1306.h is including a resource around line 18 that is included someplace else and therefore causes the multiple definition error. More likely I'm totally missing something important.

Any ideas or suggestions?

Thanks!

Chris

[S.Ma]

does your ssd1306.h file have the code wrap something like this:

#ifndef _SSD1306_H_

#define _SSD1306_H_

(...)

#endif

?

[CKohl.3]

I solved this, but I don't understand the root cause.

I found copies of most or all of the STM32F0xx_HAL_Driver .c files that were causing the issue. These copies were identical except for a " 3.c" extension. I have no idea how these were created, but when I deleted them the issue above went away.