stm_usart.h File Reference

To be used with the USART peripherals on STM32 microcontrollers. More...

#include <libopencm3/stm32/gpio.h>
#include <libopencm3/stm32/usart.h>
#include <stdint.h>

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Macros
#define	setup_usart(usart, baud, tx_port, tx_pin, tx_af, rx_port, rx_pin, rx_af)
	Setup a USART.
#define	def_usart_isr_push_rx_to_circ_buf(isr_name, usart, circular_buffer)
	Define the ISR for a USART to push rx bytes to a circular buffer.

Detailed Description

To be used with the USART peripherals on STM32 microcontrollers.

Definition in file stm_usart.h.

Macro Definition Documentation

def_usart_isr_push_rx_to_circ_buf

#define def_usart_isr_push_rx_to_circ_buf	(		isr_name,
			usart,
			circular_buffer )

Value:

  _Pragma("GCC diagnostic ignored \"-Wshadow\"")                               \
      _Pragma("GCC diagnostic push")                                           \
          _Pragma("GCC diagnostic ignored \"-Wunused-function\"")              \
              _Pragma("GCC diagnostic push") void                              \
              isr_name(void) {                                                 \
    _Pragma("GCC diagnostic pop") _Pragma(                                     \
        "GCC diagnostic pop") if (((USART_CR1(usart) & USART_CR1_RXNEIE) !=    \
                                   0) &&                                       \
                                  ((USART_ISR(usart) & USART_ISR_RXNE) !=      \
                                   0)) {                                       \
      circular_buffer_push_back_uint8(circular_buffer,                         \
                                      usart_recv(usart) & 0xFF);               \
    }                                                                          \
  }

Define the ISR for a USART to push rx bytes to a circular buffer.

Defines the interrupt handler for the given USART. The interrupt handler will push all rx bytes to the back of the circular buffer the user provides.

Notes

DON'T USE A SEMICOLON AFTER THIS MACRO.

Use atomic operations to remove data from the front of the circular buffer like CM_ATOMIC_BLOCK() {}

Make sure to setup the USART and run both nvic_enable_irq(NVIC_<usart>_IRQ); and usart_enable_rx_interrupt(<usart>);

Not sure if this works with UARTs or LPUARTs

Parameters

isr_name: usart1_isr, usart2_isr, ...

usart: the USART you want to use like USART1, USART2, ...

circular_buffer: a pointer to a circular_buffer_uint8 that you want received bytes pushed_back on.

Definition at line 95 of file stm_usart.h.

setup_usart

#define setup_usart	(		usart,
			baud,
			tx_port,
			tx_pin,
			tx_af,
			rx_port,
			rx_pin,
			rx_af )

Value:

  gpio_mode_setup(tx_port, GPIO_MODE_AF, GPIO_PUPD_NONE, tx_pin);              \
  gpio_set_af(tx_port, tx_af, tx_pin);                                         \
                                                                               \
  gpio_mode_setup(rx_port, GPIO_MODE_AF, GPIO_PUPD_NONE, rx_pin);              \
  gpio_set_af(rx_port, rx_af, rx_pin);                                         \
                                                                               \
  usart_set_baudrate(usart, baud);                                             \
  usart_set_databits(usart, 8);                                                \
  usart_set_parity(usart, USART_PARITY_NONE);                                  \
  usart_set_stopbits(usart, USART_CR2_STOPBITS_1);                             \
  usart_set_mode(usart, USART_MODE_TX_RX);                                     \
  usart_set_flow_control(usart, USART_FLOWCONTROL_NONE)

Setup a USART.

Setup a USART in async, 8 bit, 1 stop bit, no parity, no flow-control, tx-rx mode.

Notes

The user must setup the peripheral clocks for both this USART and the GPIO input/outpu port(s).

The user must enable the USART when ready with: usart_enable(usart);

This macro takes care of setting up the GPIO pins.

Not sure if this works with UARTs or LPUARTs

Parameters

usart: the USART you want to use like USART1, USART2, ...

baud: the baud rate of the USART, uint32_t

tx_port: GPIOA, GPIOB, ...

tx_pin: GPIO0, GPIO1, ...

tx_af: alternate function for the given pin/port to hook it up to the USART, e.g. GPIO_AF0, GPIO_AF1, ...

rx_port: GPIOA, GPIOB, ...

rx_pin: GPIO0, GPIO1, ...

rx_af: alternate function for the given pin/port to hook it up to the USART, e.g. GPIO_AF0, GPIO_AF1, ...

Definition at line 52 of file stm_usart.h.