Mongoose_Arduino_RadioHead/src/RHGenericSPI.h

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// RHGenericSPI.h
// Author: Mike McCauley (mikem@airspayce.com)
// Copyright (C) 2011 Mike McCauley
// Contributed by Joanna Rutkowska
// $Id: RHGenericSPI.h,v 1.7 2014/04/14 08:37:11 mikem Exp $
#ifndef RHGenericSPI_h
#define RHGenericSPI_h
#include <RadioHead.h>
#if (RH_PLATFORM == RH_PLATFORM_ARDUINO)
#include <SPI.h> // for SPI_HAS_TRANSACTION and SPISettings
#endif
/////////////////////////////////////////////////////////////////////
/// \class RHGenericSPI RHGenericSPI.h <RHGenericSPI.h>
/// \brief Base class for SPI interfaces
///
/// This generic abstract class is used to encapsulate hardware or software SPI interfaces for
/// a variety of platforms.
/// The intention is so that driver classes can be configured to use hardware or software SPI
/// without changing the main code.
///
/// You must provide a subclass of this class to driver constructors that require SPI.
/// A concrete subclass that encapsualates the standard Arduino hardware SPI and a bit-banged
/// software implementation is included.
///
/// Do not directly use this class: it must be subclassed and the following abstract functions at least
/// must be implmented:
/// - begin()
/// - end()
/// - transfer()
class RHGenericSPI
{
public:
/// \brief Defines constants for different SPI modes
///
/// Defines constants for different SPI modes
/// that can be passed to the constructor or setMode()
/// We need to define these in a device and platform independent way, because the
/// SPI implementation is different on each platform.
typedef enum
{
DataMode0 = 0, ///< SPI Mode 0: CPOL = 0, CPHA = 0
DataMode1, ///< SPI Mode 1: CPOL = 0, CPHA = 1
DataMode2, ///< SPI Mode 2: CPOL = 1, CPHA = 0
DataMode3, ///< SPI Mode 3: CPOL = 1, CPHA = 1
} DataMode;
/// \brief Defines constants for different SPI bus frequencies
///
/// Defines constants for different SPI bus frequencies
/// that can be passed to setFrequency().
/// The frequency you get may not be exactly the one according to the name.
/// We need to define these in a device and platform independent way, because the
/// SPI implementation is different on each platform.
typedef enum
{
Frequency1MHz = 0, ///< SPI bus frequency close to 1MHz
Frequency2MHz, ///< SPI bus frequency close to 2MHz
Frequency4MHz, ///< SPI bus frequency close to 4MHz
Frequency8MHz, ///< SPI bus frequency close to 8MHz
Frequency16MHz ///< SPI bus frequency close to 16MHz
} Frequency;
/// \brief Defines constants for different SPI endianness
///
/// Defines constants for different SPI endianness
/// that can be passed to setBitOrder()
/// We need to define these in a device and platform independent way, because the
/// SPI implementation is different on each platform.
typedef enum
{
BitOrderMSBFirst = 0, ///< SPI MSB first
BitOrderLSBFirst, ///< SPI LSB first
} BitOrder;
/// Constructor
/// Creates an instance of an abstract SPI interface.
/// Do not use this contructor directly: you must instead use on of the concrete subclasses provided
/// such as RHHardwareSPI or RHSoftwareSPI
/// \param[in] frequency One of RHGenericSPI::Frequency to select the SPI bus frequency. The frequency
/// is mapped to the closest available bus frequency on the platform.
/// \param[in] bitOrder Select the SPI bus bit order, one of RHGenericSPI::BitOrderMSBFirst or
/// RHGenericSPI::BitOrderLSBFirst.
/// \param[in] dataMode Selects the SPI bus data mode. One of RHGenericSPI::DataMode
RHGenericSPI(Frequency frequency = Frequency1MHz, BitOrder bitOrder = BitOrderMSBFirst, DataMode dataMode = DataMode0);
/// Transfer a single octet to and from the SPI interface
/// \param[in] data The octet to send
/// \return The octet read from SPI while the data octet was sent
virtual uint8_t transfer(uint8_t data) = 0;
/// SPI Configuration methods
/// Enable SPI interrupts (if supported)
/// This can be used in an SPI slave to indicate when an SPI message has been received
virtual void attachInterrupt() {};
/// Disable SPI interrupts (if supported)
/// This can be used to diable the SPI interrupt in slaves where that is supported.
virtual void detachInterrupt() {};
/// Initialise the SPI library.
/// Call this after configuring and before using the SPI library
virtual void begin() = 0;
/// Disables the SPI bus (leaving pin modes unchanged).
/// Call this after you have finished using the SPI interface
virtual void end() = 0;
/// Sets the bit order the SPI interface will use
/// Sets the order of the bits shifted out of and into the SPI bus, either
/// LSBFIRST (least-significant bit first) or MSBFIRST (most-significant bit first).
/// \param[in] bitOrder Bit order to be used: one of RHGenericSPI::BitOrder
virtual void setBitOrder(BitOrder bitOrder);
/// Sets the SPI data mode: that is, clock polarity and phase.
/// See the Wikipedia article on SPI for details.
/// \param[in] dataMode The mode to use: one of RHGenericSPI::DataMode
virtual void setDataMode(DataMode dataMode);
/// Sets the SPI clock divider relative to the system clock.
/// On AVR based boards, the dividers available are 2, 4, 8, 16, 32, 64 or 128.
/// The default setting is SPI_CLOCK_DIV4, which sets the SPI clock to one-quarter
/// the frequency of the system clock (4 Mhz for the boards at 16 MHz).
/// \param[in] frequency The data rate to use: one of RHGenericSPI::Frequency
virtual void setFrequency(Frequency frequency);
// Try to add SPI Transaction support
// Note: Maybe add some way to set SPISettings?
virtual void beginTransaction() {};
virtual void endTransaction() {};
protected:
/// The configure SPI Bus frequency, one of RHGenericSPI::Frequency
Frequency _frequency; // Bus frequency, one of RHGenericSPI::Frequency
/// Bit order, one of RHGenericSPI::BitOrder
BitOrder _bitOrder;
/// SPI bus mode, one of RHGenericSPI::DataMode
DataMode _dataMode;
};
#endif