RHHardwareSPI.h

00001 // RHHardwareSPI.h
00002 // Author: Mike McCauley (mikem@airspayce.com)
00003 // Copyright (C) 2011 Mike McCauley
00004 // Contributed by Joanna Rutkowska
00005 // $Id: RHHardwareSPI.h,v 1.9 2014/08/12 00:54:52 mikem Exp $
00006 
00007 #ifndef RHHardwareSPI_h
00008 #define RHHardwareSPI_h
00009 
00010 #include <RHGenericSPI.h>
00011 
00012 /////////////////////////////////////////////////////////////////////
00013 /// \class RHHardwareSPI RHHardwareSPI.h <RHHardwareSPI.h>
00014 /// \brief Encapsulate a hardware SPI bus interface
00015 ///
00016 /// This concrete subclass of GenericSPIClass encapsulates the standard Arduino hardware and other
00017 /// hardware SPI interfaces.
00018 class RHHardwareSPI : public RHGenericSPI
00019 {
00020 #ifdef RH_HAVE_HARDWARE_SPI
00021 public:
00022     /// Constructor
00023     /// Creates an instance of a hardware SPI interface, using whatever SPI hardware is available on
00024     /// your processor platform. On Arduino and Uno32, uses SPI. On Maple, uses HardwareSPI.
00025     /// \param[in] frequency One of RHGenericSPI::Frequency to select the SPI bus frequency. The frequency
00026     /// is mapped to the closest available bus frequency on the platform.
00027     /// \param[in] bitOrder Select the SPI bus bit order, one of RHGenericSPI::BitOrderMSBFirst or 
00028     /// RHGenericSPI::BitOrderLSBFirst.
00029     /// \param[in] dataMode Selects the SPI bus data mode. One of RHGenericSPI::DataMode
00030     RHHardwareSPI(Frequency frequency = Frequency1MHz, BitOrder bitOrder = BitOrderMSBFirst, DataMode dataMode = DataMode0);
00031 
00032     /// Transfer a single octet to and from the SPI interface
00033     /// \param[in] data The octet to send
00034     /// \return The octet read from SPI while the data octet was sent
00035     uint8_t transfer(uint8_t data);
00036 
00037     // SPI Configuration methods
00038     /// Enable SPI interrupts
00039     /// This can be used in an SPI slave to indicate when an SPI message has been received
00040     /// It will cause the SPI_STC_vect interrupt vectr to be executed
00041     void attachInterrupt();
00042 
00043     /// Disable SPI interrupts
00044     /// This can be used to diable the SPI interrupt in slaves where that is supported.
00045     void detachInterrupt();
00046     
00047     /// Initialise the SPI library
00048     /// Call this after configuring the SPI interface and before using it to transfer data.
00049     /// Initializes the SPI bus by setting SCK, MOSI, and SS to outputs, pulling SCK and MOSI low, and SS high. 
00050     void begin();
00051 
00052     /// Disables the SPI bus (leaving pin modes unchanged). 
00053     /// Call this after you have finished using the SPI interface.
00054     void end();
00055 #else
00056     // not supported on ATTiny etc
00057     uint8_t transfer(uint8_t data) {return 0;}
00058     void begin(){}
00059     void end(){}
00060 
00061 #endif
00062 };
00063 
00064 // Built in default instance
00065 extern RHHardwareSPI hardware_spi;
00066 
00067 #endif