SPI Library
The SPI port is a full duplex three wire interface primarily used to
communicate between embedded peripherals. The ATmega168, ATmega328 and
ATmega644 support speeds up to half of the clock frequency.
The port is single buffered in the transmit direction and double
buffered in the receive direction.
void loop() {
// create a buffer and intialize each element
unsigned char buf[2];
buf[0] = 0xFF;
buf[1] = 0x00;
// write the two bytes in the buffer to the SPI port
spi.write(buf,2);
}
#include <SPI.h>
Public Member Functions |
| | SPI (unsigned char timeout=SPI_TIMEOUT, unsigned char mosi_pin=NB1A_MOSI_PIN, unsigned char miso_pin=NB1A_MISO_PIN, unsigned char sck_pin=NB1A_SCK_PIN) |
| void | init (unsigned char spcr, unsigned char spsr) |
| char | write (unsigned char *data, unsigned char num_chars) |
| char | read (unsigned char *data, unsigned char max_num_chars) |
Detailed Description
Serial Peripheral Interface (SPI) Class
Definition at line 27 of file SPI.h.
Constructor & Destructor Documentation
| SPI::SPI |
( |
unsigned char |
timeout = SPI_TIMEOUT, |
|
|
unsigned char |
mosi_pin = NB1A_MOSI_PIN, |
|
|
unsigned char |
miso_pin = NB1A_MISO_PIN, |
|
|
unsigned char |
sck_pin = NB1A_SCK_PIN | |
|
) |
| | |
Constructor for the SPI Class.
The pin assignments for the SPI port need to be passed to the constructor. The pin numbers need to be Arduino (or Sanguino) pin numbers since initialization is performed using pinMode and digitalWrite commands. The default values are for the wiblocks NB1A board. Constants for the NB2A board (which is Sanguino compatible) are defined in the header file.
No hardware is initialized by the constructor. A call to Init is required to initialize the pins and setup the control register (SPCR) and the status register (SPSR).
- Parameters:
-
| [in] | timeout | number of milliseconds to wait for the SPI port to complete transmission. the default value is 10mS. |
| [in] | mosi_pin | the pin number of the MOSI pin. |
| [in] | miso_pin | the pin number of the MISO pin. |
| [in] | sck_pin | the pin number of the SCK pin. |
- Todo:
- Add circular buffers for interrupt driven IO
Definition at line 33 of file SPI.cpp.
Member Function Documentation
| void SPI::init |
( |
unsigned char |
spcr, |
|
|
unsigned char |
spsr | |
|
) |
| | |
Initialize the SPI control register and SPI status register.
- Parameters:
-
| [in] | spcr | SPI control register |
| [in] | spsr | SPI status register |
Definition at line 51 of file SPI.cpp.
| char SPI::read |
( |
unsigned char * |
data, |
|
|
unsigned char |
max_num_chars | |
|
) |
| | |
Read characters from the SPI port
- Parameters:
-
| [in] | *data | pointer to an array of characters that will receive the characters that are read. |
| [in] | max_num_chars | number of characters to read. |
- Todo:
- Write it ;)
Definition at line 96 of file SPI.cpp.
| char SPI::write |
( |
unsigned char * |
data, |
|
|
unsigned char |
num_chars | |
|
) |
| | |
Write characters to the SPI port.
- Parameters:
-
| [in] | *data | pointer to an array of characters to be transmitted |
| [in] | num_chars | number of characters to be transmitted. |
Definition at line 69 of file SPI.cpp.
The documentation for this class was generated from the following files:
Educational Kits and Rapid Prototyping Tools
1.7.1