UART DRIVER

UART driver reusable on different hardwares.

Supported Hardware

• NUCLEO-H745ZI-Q

Functions Guide

• uart_initialize : initialize the interfaces.
• uart_send : sends data as raw bites.
• uart_send_message : sends data as message.
• uart_send_lowpulse : sends a low pulse.
• uart_callback_add : adds a callback.

How to use

• Include the header file drv_uart.h.

• Enable the UART peripheral in the .ioc file.

• Copy the drv_uart_config.h.template in the parent folder and rename it to drv_uart_config.h. If you want to use the pin pulse or the raw uart mode please enable a timer and uncomment/set correctly the definitions.

• Create an instance of uart_t to be used as the handler and afterwards create an array of uart_interface_t (uart_interface_t interfaces[]={interface1, interface2...}). For each interface, define:

  • interface.mx_init: UART initializing function generated by the configuration tool.
  • interface.huart : handler of choice (ex. huart4).
  • interface. tx_port : port used for the low pulse (define only if needed).
  • interface. tx_pin : pin used for the low pulse (define only if needed).
  • interface. in_buffer : address of 8-bit array for reception/transmission buffer.
  • interface. in_buffer_sz : position in the buffer.
  • interface. in_buffer_tsz : buffer size.
  • interface.raw_timout : we assume the message ends after the timeout.
  • interface.max_raw_timout : maximum timeout for a raw message

• Use the uart_send_message function to send a message:

   uart_send_message(&uart_instance, message, b64_sz);

• Messages are read thought the callback function. To add a callback function use uart_callback_add.

• An example of callback function:

static void cb_uart(UART_HandleTypeDef *huart, uint8_t *buffer, uint32_t size)
{
   string message_base64;
   uint8_t ser_dt[13];
			
   base64_decode(buffer, size, ser_dt);
					
   iqueue_enqueue(&q_uart, &dec_frame);
} 

  uart_callback_add(&uart_instance, cb_uart);

Example

Let's consider a NUCLEO-H7A3ZI-Q. UART4 has been enabled in the .ioc file

static uint8_t uart_buffer[256];

uart_t uart_instance_ = {
		.mx_init = MX_UART4_Init,
		.in_buffer_tsz = 250,
		.in_buffer_sz = 0,
		.huart = &huart4,
		.in_buffer = uart_buffer,
};

uart_initialize(&uart_instance);

uart_send_message(&uart_instance, message, b64_sz);

uint8_t message[32];

uart_callback_add(&uart_instance, cb_uart);