RS232 Driver AVR8. More...

#include "user_config.h"
#include "rs232.h"

Functions
void	uart_rx_flush (uint8_t uart)
	Flush receive ring buffer for specified uart. More...

int	uart0_getchar (void *f __attribute__((unused)))
	UART receive character function using avr-libc. More...

int	uart0_putchar (int c, void *f __attribute__((unused)))
	UART transmit character function using avr-libc. More...

uint16_t	uart_ubr (uint32_t baud, int u2x, uint32_t actual)
	UART baud rate caluculation We compute the best values of baud rate register and prescale. More...

uint32_t	uart_init (uint8_t uart, uint32_t baud)
	UART initialization function that works with avr-libc functions. More...

	ISR (USART0_RX_vect)
	UART 0 Receive Interrupt runction. More...

void	uart_rx_interrupt (uint8_t uart, uint8_t data)
	UART Receive Interrupt task. More...

int	uart_peek_tail (uint8_t uart)
	Return character waiting in ring buffer without removing it. More...

int	uart_get_tail (uint8_t uart)
	Return next character from ring buffer. More...

int	uart_rx_count (uint8_t uart)
	return count of character count waiting in UART ring buffer. More...

int	uart_rx_byte (uint8_t uart)
	Recive character character from uart. More...

int	uart_getchar (uint8_t uart)
	Receive character from uart with option CR/LF conversion. More...

int	uart_tx_byte (int c, uint8_t uart)
	Transmit 1 byte on uart. More...

int	uart_putchar (int c, int uart)
	Transmit 1 byte on uart. More...

int	uart_keyhit (uint8_t uart)
	Do we have receive characters waiting ?. More...

int	uart_put (int c)
	Transmit a character on UART 0. More...

int	uart_get (void)
	Receive a character from UART 0. More...

int	get_line (char *buff, int len)
	Get a line from UART 0 up to a maximum of len bytes. More...

Variables
struct _uart	uarts [UARTS]
	Uart ring buffers. More...

Detailed Description

RS232 Driver AVR8.

Edit History

[1.0] [Mike Gore] Initial revision of file.

Copyright © 2014-2020 Mike Gore, Inc. All rights reserved.

Definition in file rs232.c.

Function Documentation

◆ get_line()

int get_line	(	char *	buff,
		int	len
	)

Get a line from UART 0 up to a maximum of len bytes.

Parameters

[in]	buff	line input buffer
[in]	len	line length maximum

Returns: void

Definition at line 421 of file rs232.c.

◆ ISR()

ISR ( USART0_RX_vect )

UART 0 Receive Interrupt runction.

See also: uart_rx_interrupt().

Definition at line 185 of file rs232.c.

◆ uart0_getchar()

int uart0_getchar ( void *f __attribute__(unused) )

UART receive character function using avr-libc.

Parameters

[in] f unused FILE *stream pointer.

Returns: uart_getchar(0);.

See also: fdevopen() from avr-libc.

Definition at line 45 of file rs232.c.

Referenced by uart_get(), and uart_init().

◆ uart0_putchar()

int uart0_putchar	(	int	c,
		void *f	__attribute__(unused)
	)

UART transmit character function using avr-libc.

Parameters

[in]	c	character to send.
[in]	f	unused FILE *stream pointer.

Returns: uart_putchar(c, 0);.

See also: fdevopen() from avr-libc.

Definition at line 58 of file rs232.c.

Referenced by uart_init(), and uart_put().

◆ uart_get()

int uart_get ( void )

Receive a character from UART 0.

Returns: character

Definition at line 411 of file rs232.c.

Referenced by get_line().

◆ uart_get_tail()

int uart_get_tail ( uint8_t uart )

Return next character from ring buffer.

Wait for at least one character.
Update index pointers and character count.

Parameters

[in] uart uart number to read.

Returns: character.; 0 on error.

See also: uart_rx_count().

Definition at line 249 of file rs232.c.

Referenced by uart_rx_byte().

◆ uart_getchar()

int uart_getchar ( uint8_t uart )

Receive character from uart with option CR/LF conversion.

CR/LF processing is disabled at the moment.

Parameters

[in] uart uart number.

Returns: Character.

Definition at line 312 of file rs232.c.

Referenced by uart0_getchar().

◆ uart_init()

uint32_t uart_init	(	uint8_t	uart,
		uint32_t	baud
	)

UART initialization function that works with avr-libc functions.

Parameters

[in]	uart	UART number.
[in]	baud	Baud Rate in HZ.

Returns: actual baud rate, closest we could get with register settings

See also: fdevopen() avr-libc function that attaches uart functions to getchar and putchar POSIX functions.

actual baud rate

Definition at line 117 of file rs232.c.

Referenced by main().

◆ uart_keyhit()

int uart_keyhit ( uint8_t uart )

Do we have receive characters waiting ?.

Returns non zero if there are any caracters.

Parameters

[in] uart uart number.

Returns: Character count in receive buffer.

Definition at line 394 of file rs232.c.

Referenced by gpib_detect_PP(), gpib_error_test(), gpib_read_byte(), gpib_trace_task(), and gpib_write_byte().

◆ uart_peek_tail()

int uart_peek_tail ( uint8_t uart )

Return character waiting in ring buffer without removing it.

Returns: character.; 0 on error.

Definition at line 227 of file rs232.c.

◆ uart_put()

int uart_put ( int c )

Transmit a character on UART 0.

Parameters

[in] c character to write

Returns: void

Definition at line 403 of file rs232.c.

Referenced by get_line().

◆ uart_putchar()

int uart_putchar	(	int	c,
		int	uart
	)

Transmit 1 byte on uart.

CR/LF Output translation.
Parameters

[in] c transmit character.

[in] uart uart number.

Returns
void.

Definition at line 376 of file rs232.c.

Referenced by uart0_putchar().

◆ uart_rx_byte()

int uart_rx_byte ( uint8_t uart )

Recive character character from uart.

Parameters

[in] uart uart number.

Returns: Character.

Definition at line 299 of file rs232.c.

Referenced by uart_getchar().

◆ uart_rx_count()

int uart_rx_count ( uint8_t uart )

return count of character count waiting in UART ring buffer.

Parameters

[in] uart uart number to check count for.

Returns: Character count in ring buffer.

Definition at line 277 of file rs232.c.

Referenced by uart_get_tail(), and uart_keyhit().

◆ uart_rx_flush()

void uart_rx_flush ( uint8_t uart )

Flush receive ring buffer for specified uart.

Returns: void

Definition at line 22 of file rs232.c.

Referenced by uart_init(), and user_task().

◆ uart_rx_interrupt()

void uart_rx_interrupt	(	uint8_t	uart,
		uint8_t	data
	)

UART Receive Interrupt task.

Add characters to ring receive buffer.

Parameters

[in]	uart	uart number.
[in]	data	register data.

Returns: void.

Definition at line 207 of file rs232.c.

Referenced by ISR().

◆ uart_tx_byte()

int uart_tx_byte	(	int	c,
		uint8_t	uart
	)

Transmit 1 byte on uart.

Parameters

[in]	c	transmit character.
[in]	uart	uart number.

Returns: void.

Definition at line 347 of file rs232.c.

Referenced by uart_getchar(), and uart_putchar().

◆ uart_ubr()

uint16_t uart_ubr	(	uint32_t	baud,
		int *	u2x,
		uint32_t *	actual
	)

UART baud rate caluculation We compute the best values of baud rate register and prescale.

Parameters

[in]	uart	desired baud rate in HZ
[in]	*u2x	computed prescale 1 = divide by 8, 0 = divide by 16
[in]	*actual	Actual computed baud rate, closest we could get with register settings

Returns: baud rate register value

See also: fdevopen() avr-libc function that attaches uart functions to getchar and putchar POSIX functions.

Use 8 prescale as a default

Use 16 prescale f we have a low baud rate

Definition at line 73 of file rs232.c.

Referenced by uart_init().

Variable Documentation

◆ uarts

struct _uart uarts[UARTS]

Uart ring buffers.

Definition at line 17 of file rs232.c.

Referenced by uart_get_tail(), uart_peek_tail(), uart_rx_count(), uart_rx_flush(), and uart_rx_interrupt().

Functions

Variables

Detailed Description

Function Documentation

◆ get_line()

◆ ISR()

◆ uart0_getchar()

◆ uart0_putchar()

◆ uart_get()

◆ uart_get_tail()

◆ uart_getchar()

◆ uart_init()

◆ uart_keyhit()

◆ uart_peek_tail()

◆ uart_put()

◆ uart_putchar()

◆ uart_rx_byte()

◆ uart_rx_count()

◆ uart_rx_flush()

◆ uart_rx_interrupt()

◆ uart_tx_byte()

◆ uart_ubr()

Variable Documentation

◆ uarts