This repo shows how to use (a fork of) the ssd1306 library to drive a display over I2C.
Here the STM32 F3 Discovery board is used, but the library works with other F3 boards too.
For the CMake setup I used, check out this repo.
By default, the ssd1306 library uses PB6 and PB7 as SCL and SDA pins, with internal pull-up resistors.
// main.c
#include "ssd1306.h"
ssd1306_128x32_i2c_init(); // or whatever display you're using _________________________
| ______________| ______________
| | I2C1 | | |
| | SCL(PB6)|______________________|SCL |
| | | | |
| | SDA(PB7)|______________________|SDA |
| |______________| | |
| | | |
| 3V |______________________|VCC |
| | | |
| GND|______________________|GND |
| | | |
|_STM32F3_________________| |_OLED_Display_|
Alternatively, you can use PA9 and PA10 as SCL and SDA pins, if I2C2 is available on your board. To use these pins, replace ssd1306_128x32_i2c_init() with a call to these 2 functions shown below.
#include "ssd1306.h
#include "intf/i2c/ssd1306_i2c.h"
ssd1306_i2cInitEx(1, 1, 0); // third param is the i2c address of the lcd display; use 0 to leave default
ssd1306_128x32_init(); // or whatever display you're using _________________________
| ______________| ______________
| | I2C2 | | |
| | SCL(PA9)|______________________|SCL |
| | | | |
| | SDA(PA10)|______________________|SDA |
| |______________| | |
| | | |
| 3V |______________________|VCC |
| | | |
| GND|______________________|GND |
| | | |
|_STM32F3_________________| |_OLED_Display_|
# Configure CMake
cmake \
--no-warn-unused-cli \
-DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=TRUE \
-DCMAKE_BUILD_TYPE:STRING=Debug \
-DCMAKE_TOOLCHAIN_FILE:FILEPATH=gcc-arm-none-eabi.cmake \
-Bbuild \
-G Ninja
# Build
cmake --build build -j 8
# Flash
STM32_Programmer_CLI --connect port=swd --download build/stm32f3-ssd1306-display.elf -hardRstYou don't need to worry about initializing and setting up the I2C peripheral, the ssd1306 library takes care of it already.
Make sure, however, that you include the STM32 HAL Driver library in your project; in particular, these files should be present:
STM32F3xx_HAL_Driver/Inc/stm32f3xx_hal_i2c.h
STM32F3xx_HAL_Driver/Inc/stm32f3xx_hal_i2c_ex.h
STM32F3xx_HAL_Driver/Src/stm32f3xx_hal_i2c.c
STM32F3xx_HAL_Driver/Src/stm32f3xx_hal_i2c_ex.c
PS: If you use CubeMX to generate the project's boilerplate, check that the i2c header file is indeed included in Core/Inc/stm32f3xx_hal_conf.h:
#define HAL_I2C_MODULE_ENABLED
// ...
#ifdef HAL_I2C_MODULE_ENABLED
#include "stm32f3xx_hal_i2c.h"
#endif /* HAL_I2C_MODULE_ENABLED */