Advanced use case - Send a packet of serial data

In this use case, the USART module is configured for:

• Using USARTD0
• Baudrate: 9600
• Character length: 8 bit
• Parity mode: Disabled
• Stop bit: None
• RS232 mode

The use case sends a string of text through the USART.

Setup steps

Prerequisites

1. System Clock Management (sysclk)

Example code

The following configuration must be added to the project (typically to a conf_uart_serial.h file, but it can also be added to your main application file.):

Note

The following takes SAM3X configuration for example, other devices have similar configuration, but their parameters may be different, refer to corresponding header files.

#define USART_SERIAL                     &USARTD0
#define USART_SERIAL_BAUDRATE            9600
#define USART_SERIAL_CHAR_LENGTH         US_MR_CHRL_8_BIT
#define USART_SERIAL_PARITY              US_MR_PAR_NO
#define USART_SERIAL_STOP_BIT            false

Add to application initialization:

sysclk_init();

static usart_serial_options_t usart_options = {
   .baudrate = USART_SERIAL_BAUDRATE,
   .charlength = USART_SERIAL_CHAR_LENGTH,
   .paritytype = USART_SERIAL_PARITY,
   .stopbits = USART_SERIAL_STOP_BIT
};

usart_serial_init(USART_SERIAL, &usart_options);

Workflow

1. Initialize system clock:

   • sysclk_init(); 

2. Create USART options struct:

   • static usart_serial_options_t usart_options = {
        .baudrate = USART_SERIAL_BAUDRATE,
        .charlength = USART_SERIAL_CHAR_LENGTH,
        .paritytype = USART_SERIAL_PARITY,
        .stopbits = USART_SERIAL_STOP_BIT
     };

3. Initialize in RS232 mode:

   • usart_serial_init(USART_SERIAL_EXAMPLE, &usart_options); 

Usage steps

Example code

Add to, e.g., main loop in application C-file:

usart_serial_write_packet(USART_SERIAL, "Test String", strlen("Test String"));

Workflow

1. Write a string of text to the USART:

   • usart_serial_write_packet(USART_SERIAL, "Test String", strlen("Test String"));