Interrupt UART library using the built-in UART with transmit and receive circular buffers. More...
Macros | |
| #define | UART_BAUD_SELECT(baudRate, xtalCpu) ((xtalCpu)/((baudRate)*16l)-1) |
| UART Baudrate Expression. More... | |
| #define | UART_BAUD_SELECT_DOUBLE_SPEED(baudRate, xtalCpu) (((xtalCpu)/((baudRate)*8l)-1)|0x8000) |
| UART Baudrate Expression for ATmega double speed mode. More... | |
| #define | UART_RX_BUFFER_SIZE 64 |
| #define | UART_TX_BUFFER_SIZE 64 |
| #define | UART_FRAME_ERROR 0x0800 /* Framing Error by UART */ |
| #define | UART_OVERRUN_ERROR 0x0400 /* Overrun condition by UART */ |
| #define | UART_BUFFER_OVERFLOW 0x0200 /* receive ringbuffer overflow */ |
| #define | UART_NO_DATA 0x0100 /* no receive data available */ |
| #define | uart_puts_P(__s) uart_puts_p(PSTR(__s)) |
| Macro to automatically put a string constant into program memory. More... | |
| #define | uart1_puts_P(__s) uart1_puts_p(PSTR(__s)) |
| Macro to automatically put a string constant into program memory. More... | |
Functions | |
| void | uart_init (unsigned int baudrate) |
| Initialize UART and set baudrate. More... | |
| unsigned int | uart_getc (void) |
| Get received byte from ringbuffer. More... | |
| void | uart_putc (unsigned char data) |
| Put byte to ringbuffer for transmitting via UART. More... | |
| void | uart_puts (const char *s) |
| Put string to ringbuffer for transmitting via UART. More... | |
| void | uart_puts_p (const char *progmem_s) |
| Put string from program memory to ringbuffer for transmitting via UART. More... | |
| void | uart1_init (unsigned int baudrate) |
| Initialize USART1 (only available on selected ATmegas) More... | |
| unsigned int | uart1_getc (void) |
| Get received byte of USART1 from ringbuffer. (only available on selected ATmega) More... | |
| void | uart1_putc (unsigned char data) |
| Put byte to ringbuffer for transmitting via USART1 (only available on selected ATmega) More... | |
| void | uart1_puts (const char *s) |
| Put string to ringbuffer for transmitting via USART1 (only available on selected ATmega) More... | |
| void | uart1_puts_p (const char *s) |
| Put string from program memory to ringbuffer for transmitting via USART1 (only available on selected ATmega) More... | |
Detailed Description
Interrupt UART library using the built-in UART with transmit and receive circular buffers.
This library can be used to transmit and receive data through the built in UART.
An interrupt is generated when the UART has finished transmitting or receiving a byte. The interrupt handling routines use circular buffers for buffering received and transmitted data.
The UART_RX_BUFFER_SIZE and UART_TX_BUFFER_SIZE constants define the size of the circular buffers in bytes. Note that these constants must be a power of 2. You may need to adapt this constants to your target and your application by adding CDEFS += -DUART_RX_BUFFER_SIZE=nn -DUART_RX_BUFFER_SIZE=nn to your Makefile.
- Note
- Based on Atmel Application Note AVR306
Macro Definition Documentation
| #define uart1_puts_P | ( | __s | ) | uart1_puts_p(PSTR(__s)) |
| #define UART_BAUD_SELECT | ( | baudRate, | |
| xtalCpu | |||
| ) | ((xtalCpu)/((baudRate)*16l)-1) |
UART Baudrate Expression.
constants and macros
- Parameters
-
xtalCpu system clock in Mhz, e.g. 4000000L for 4Mhz baudRate baudrate in bps, e.g. 1200, 2400, 9600
Definition at line 67 of file uart.h.
Referenced by gps_init().
| #define UART_BAUD_SELECT_DOUBLE_SPEED | ( | baudRate, | |
| xtalCpu | |||
| ) | (((xtalCpu)/((baudRate)*8l)-1)|0x8000) |
| #define UART_BUFFER_OVERFLOW 0x0200 /* receive ringbuffer overflow */ |
Definition at line 95 of file uart.h.
Referenced by gps_get_char(), and SIGNAL().
| #define UART_FRAME_ERROR 0x0800 /* Framing Error by UART */ |
test if the size of the circular buffers fits into SRAM
high byte error return code of uart_getc()
| #define UART_NO_DATA 0x0100 /* no receive data available */ |
Definition at line 96 of file uart.h.
Referenced by gps_get_char(), and uart_getc().
| #define UART_OVERRUN_ERROR 0x0400 /* Overrun condition by UART */ |
| #define uart_puts_P | ( | __s | ) | uart_puts_p(PSTR(__s)) |
| #define UART_RX_BUFFER_SIZE 64 |
| #define UART_TX_BUFFER_SIZE 64 |
Function Documentation
| unsigned int uart1_getc | ( | void | ) |
Get received byte of USART1 from ringbuffer. (only available on selected ATmega)
- See also
- uart_getc
| void uart1_init | ( | unsigned int | baudrate | ) |
Initialize USART1 (only available on selected ATmegas)
- See also
- uart_init
| void uart1_putc | ( | unsigned char | data | ) |
Put byte to ringbuffer for transmitting via USART1 (only available on selected ATmega)
- See also
- uart_putc
| void uart1_puts | ( | const char * | s | ) |
Put string to ringbuffer for transmitting via USART1 (only available on selected ATmega)
- See also
- uart_puts
| void uart1_puts_p | ( | const char * | s | ) |
Put string from program memory to ringbuffer for transmitting via USART1 (only available on selected ATmega)
- See also
- uart_puts_p
| unsigned int uart_getc | ( | void | ) |
Get received byte from ringbuffer.
Returns in the lower byte the received character and in the higher byte the last receive error. UART_NO_DATA is returned when no data is available.
- Returns
- lower byte: received byte from ringbuffer
-
higher byte: last receive status
- 0 successfully received data from UART
- UART_NO_DATA
no receive data available - UART_BUFFER_OVERFLOW
Receive ringbuffer overflow. We are not reading the receive buffer fast enough, one or more received character have been dropped - UART_OVERRUN_ERROR
Overrun condition by UART. A character already present in the UART UDR register was not read by the interrupt handler before the next character arrived, one or more received characters have been dropped. - UART_FRAME_ERROR
Framing Error by UART
uart_getc() return byte from ringbuffer Returns: lower byte: received byte from ringbuffer higher byte: last receive error
< no data available
calculate / store buffer index
get data from receive buffer
Definition at line 390 of file uart.c.
References UART_NO_DATA, and UART_RX_BUFFER_MASK.
Referenced by gps_get_char().
| void uart_init | ( | unsigned int | baudrate | ) |
Initialize UART and set baudrate.
function prototypes
- Parameters
-
baudrate Specify baudrate using macro UART_BAUD_SELECT()
uart_init() initialize UART and set baudrate
- Parameters
-
[in] baudrate using macro UART_BAUD_SELECT()
Definition at line 313 of file uart.c.
Referenced by gps_init().
| void uart_putc | ( | unsigned char | data | ) |
Put byte to ringbuffer for transmitting via UART.
- Parameters
-
data byte to be transmitted
uart_putc() write byte to ringbuffer for transmitting via UART
- Parameters
-
[in] data byte to be transmitted
wait for free space in buffer
enable UDRE interrupt
Definition at line 416 of file uart.c.
References UART_TX_BUFFER_MASK.
Referenced by uart_puts(), and uart_puts_p().
| void uart_puts | ( | const char * | s | ) |
Put string to ringbuffer for transmitting via UART.
The string is buffered by the uart library in a circular buffer and one character at a time is transmitted to the UART using interrupts. Blocks if it can not write the whole string into the circular buffer.
- Parameters
-
s string to be transmitted
uart_puts() transmit string to UART
- Parameters
-
[in] s string to be transmitted
Definition at line 440 of file uart.c.
References uart_putc().
| void uart_puts_p | ( | const char * | progmem_s | ) |
Put string from program memory to ringbuffer for transmitting via UART.
The string is buffered by the uart library in a circular buffer and one character at a time is transmitted to the UART using interrupts. Blocks if it can not write the whole string into the circular buffer.
- Parameters
-
progmem_s program memory string to be transmitted
- See also
- uart_puts_P
uart_puts_p() transmit string from program memory to UART
- Parameters
-
[in] progmem_s program memory string to be transmitted
Definition at line 452 of file uart.c.
References uart_putc().
