Step3 Introduction to the UART

UART and new board introduction 34min

Target description
Following this tutorial, you will:

• get familiar with the L475 IoT Node Discovery board,
• learn how to program and use a RS232 serial link on:
  • the previously used NUCLEO-L476RG board
    
  • the L475 IoT Node Discovery board (B-L475E-IOT01A ).
    

Prerequisites

• Previous Tutorials:
  
  • Step1: Tools Installation and First test
    
  • Step2: Blinking LED with STM32CubeMX and HAL

Hardware
The hardware requirements to start the application are the following:

• NUCLEO-L476RG board (64-pin)
  
• STM32L4 Discovery kit IoT node (B-L475E-IOT01A )
  
• USB cables Type-A to Mini-B and Type-A to Micro-B

1 Introduction to the UART I/F on NUCLEO-L476RG

12min
Create NUCLEO-L476RG UART project using STM32CubeMX

• Create a new project using STM32CubeMX.
  
• Select NUCLEO-L476RG board using Board Selector.
  
• Answer Yes to Initialize all peripherals with their default mode ? popup.
  
• In Pinout view tab, check that USART2 mode is configured to Asynchronous, PA2 is connected to USART2_TX and PA3 is connected to USART2_RX.
  

• Click on USART2 button in Configuration tab and set Word Length to 8 Bits.
  
• Make sure that the settings are as in the screenshot below:
  

• Disable all other USARTs.
• Switch to the Project Manager tab and select STM32CubeIDE as Toolchain / IDE and give a name to your project.
• Click on Generate Code and accept to open your project in STM32CubeIDE.

Edit and compile the NUCLEO-L476RG UART project using STM32CubeIDE

• Open main.c in Project Explorer / myproject / Src / main.c.
  
• Insert the following lines between /* USER CODE BEGIN 3 */ and /* USER CODE END 3 */:

uint8_t Test[] = "Hello World !!!\r\n"; //Data to send
HAL_UART_Transmit(&huart2,Test,sizeof(Test),10);// Sending in normal mode
HAL_Delay(1000);

• Click on Build button to compile the project.
  
• Click in Debug button to run the software.
  
• Open a console emulator such as TeraTerm. Configure the console baud rate and data bits length. the COM Port name may differ on your PC.
  
• STM32CubeIDE opens Debug perspective. Click on Resume button to execute your code.
  
• TeraTerm displays Hello World !!! string confirming you were able to program and use RS232.
  

Information

TeraTerm is a free software terminal emulator (communication program).

2 Introduction to the UART I/F on B-L475E-IOT01A (IoT Node)

22min
Quick view
The B-L475E-IOT01A Discovery kit for IoT node allows the users to develop applications with direct connection to cloud servers.
Key features
The Discovery kit enables a wide diversity of applications by exploiting low-power communication, multiway sensing and Arm^® Cortex^®-M4 core-based STM32L4 Series features.

Create B-L475E-IOT01A UART project using STM32CubeMX

• Create a new project using STM32CubeMX.
  
• Select B-L475E-IOT01A board using Board selector.
  
• Answer Yes to Initialize all peripherals with their default Mode ? popup.
  
• Verify in Pinout tab that USART1 mode is configured to Asynchronous.
  
• USART1 conflicts can be solved by (1) disabling all unnecessary features (I2C, LCD, SAI, SPI, UART, USART2) and (2) setting the pins PA9 and PB7 to reset state.
  

• Click on USART1 button in Configuration tab and set Word Length to 8 Bits, baud rate to 115200 Bits/s, Parity to None and Stop Bits to 1 as shown below.
  

• Switch to the Project Manager tab and select STM32CubeIDE as Toolchain / IDE and give a name to your project.
  
• Click on Generate Code and accept to open the project in STM32CubeIDE.
  

Edit and compile B-L475E-IOT01A UART project using STM32CubeIDE

• Open main.c in Project Explorer / myproject / Src / main.com.
  
• Insert the following lines between /* USER CODE BEGIN 3 */ and /* USER CODE END 3 */:

uint8_t Test[] = "Hello World !!!\r\n"; //Data to send
HAL_UART_Transmit(&huart1,Test,sizeof(Test),10);// Sending in normal mode
HAL_Delay(1000);

• Click on Build button to compile the project.
  
• Click on Debug button to run the software.
  
• Open a console emulator such as TeraTerm. Configure the console baud rate and data bits length. The COM Port name may differ on your PC.
  
• STM32CubeIDE opens Debug perspective. Click on Resume button to execute your code.
  
• TeraTerm displays Hello World !!! string confirming you were able to program and use RS232.
  

Now you are able to:

• use the UART I/F on NUCLEO-L476RG
  
• use the L475 IoT Node Discovery board
  
• use the UART I/F on L475 IoT Node Discovery board
  

3 References

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