Interfacing with STM32F401CC micro-controller

Guidance for testing drivers

This is documentation for handling drivers implemented in the COTS_CortexM4 folder. Layered architecture is used, which divides the software into some layers:

• APP (Application Layer) is the layer where the main.c file exists.
• HAL (Hardware Abstraction Layer) is a software program for external hardware components like sensors and actuators.
• MCAL (Microcontroller Abstraction Layer) is a software program for any peripheral inside the microcontroller.

The figure below includes all implemented drivers in the layered architecture:

1. Handling GPIO peripheral

• Enable the clock on used ports PORTA, PORTB, or PORTC using RCC driver.
• Specify the mode of the pin as INPUT or OUTPUT.
  • If OUTPUT, choose the output type and the speed of the pin.
  • If INPUT, specify the pull type as UP or DOWN or NO PULL - used for triggering pulses out of sensor or for a switch.
    

NOTES:

• If we want to get the state of a specific PIN use the function MGPIO_u8GetPinValue.
• On some STM32 GPIO pins, the user has the possibility to select alternate function inputs/outputs, this can be provided using the function MGPIO_VoidSetPinAlternativeFunction.

2. Handling EXTI peripheral

• Enable the clock on used ports PORTA, PORTB, or PORTC using RCC driver.
• Set the pin Mode as INPUT and choose the suitable pull type.
• Select the port you want using SYSCFG driver.
• Enable interrupt line (used pin) and interrupt mode as Rising or Falling or On change
• Enable interrupt using NVIC core peripheral (position number in the vector table from DataSheet).
• Use EXTI_voidSetCallBack function to be able to jump to ISR when the interrupt flag is raised.
  

NOTES:

• SYSCFG peripheral must be enabled using RCC driver.
• External interrupt can be enabled without EXTI peripheral by setting the pending flag of the used line using MNVIC_voidSetPendingFlag function in the NVIC driver.

3. Handling USART (Transimission)

• Enable the USART clock from RCC driver.
• Enable the USART by setting the UE bit in the USART_CR1 register.
• Select the desired baud rate using the USART_BRR register.
• Set the TE bit in USART_CR1 to send an idle frame as the first transmission.
• Write the data to send in the USART_DR register by using MUSART1_voidSendData function.

NOTES:

• If sending a string, use this function MUSART1_voidSendString.
• If sending a number that has more than one digit, use this function MUSART1_voidSendNumbers.

4. Handling USART (Reception)

• Enable the USART clock from RCC driver.
• Enable the USART by setting the UE bit in the USART_CR1 register.
• Select the desired baud rate using the USART_BRR register.
• Set the RE bit of the USART_CR1 register, this will enable the receiver to search for a start bit.
• Use MUSART1_u8ReceiveData function to receive data.

NOTES:

• MUSART1_u8ReceiveData function will recieve only one character in ASCII.
• If receiving more than one character, use MUSART1_voidSendNumbers function. It will return the number of received characters each one stored as an element of an array.