Posted on January 08, 2018 at 08:08As I wrote earlier you need to generate STM32CubeMX HAL project skeleton )if you decide to use HAL or LL drivers) for GPIO, I2C, and uart. It's quite easy (enable required resource - watch out pin assignments especially for I2C because by default the CubeMX will assign other pins than those marked for SCL/SDA on nucleo board).
Add basic function for UART Transmit and send a few char to see if the PC UART sees the chars. Do the same for I2c but in this case you need I2C slave device.
Cube will add the following line to your code (I do not mention variable declaration and other staff) - just to show the idea:
MX_GPIO_Init();
MX_USART2_UART_Init();
MX_I2C1_Init();
In your program you will need to add these kind of functions to play with UART:
HAL_UART_Transmit(&huart2, (uint8_t *)&ch, 1, 1000);
HAL_UART_Receive(&huart2,(uint8_t *)&ch,1,0);
Of course I omitted details like using printf/putchar etc.
For I2C you need at least:
HAL_I2C_Master_Receive(&hi2c1, deviceAddr<<1, &data, 1, 1000)
HAL_I2C_Master_Transmit(&hi2c1, deviceAddress<<1, memoryAddress, 2, 1000)
The above shows simplicity of using UART and I2c in its basic form.
The UART is trivial.
When you want to program I2C you need to know I2c address (notice for STM32 you need to shift left the address as mentioned in the line code above: deviceAddr<<1) and data format.
For OLED display based on ssd1306 you can reuse some code available in the internet - this one is really popular OR read the data sheet and program the device (I used the latter approach for a few OLED displays I have).
