A working directory for learning how to programme an ARM stm32f4 processor via the STM32F407G-DISC1 dev board from STMicroelectronics and the http://embedded.fm/ blog series Embedded Wednesdays: Getting Started In Embedded Systems.
Note that when you're setting up the HAL UART function, &huart2 refers to the number UART you chose and setup in CubeMX.
HAL_UART_Receive(&huart2, (uint8_t *) result, len, HAL_MAX_DELAY);
i.e. HAL UART 2 (huart2), HAL UART 3 (huart3), etc.
HD44780 LCD panel driver https://github.com/petoknm/PCF8574
8-bit PCF8574 I/O expander driver https://github.com/petoknm/HD44780
