Diff: RHSPIDriver.h

Revision:

0:ab4e012489ef

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RHSPIDriver.h	Thu Oct 15 01:27:00 2015 +0000
@@ -0,0 +1,92 @@
+// RHSPIDriver.h
+// Author: Mike McCauley (mikem@airspayce.com)
+// Copyright (C) 2014 Mike McCauley
+// $Id: RHSPIDriver.h,v 1.9 2014/04/23 06:00:59 mikem Exp $
+
+#ifndef RHSPIDriver_h
+#define RHSPIDriver_h
+
+#include <RHGenericDriver.h>
+#include <RHHardwareSPI.h>
+
+// This is the bit in the SPI address that marks it as a write
+#define RH_SPI_WRITE_MASK 0x80
+
+class RHGenericSPI;
+
+/////////////////////////////////////////////////////////////////////
+/// \class RHSPIDriver RHSPIDriver.h <RHSPIDriver.h>
+/// \brief Base class for a RadioHead drivers that use the SPI bus
+/// to communicate with its transport hardware.
+///
+/// This class can be subclassed by Drivers that require to use the SPI bus.
+/// It can be configured to use either the RHHardwareSPI class (if there is one available on the platform)
+/// of the bitbanged RHSoftwareSPI class. The default behaviour is to use a pre-instantiated built-in RHHardwareSPI
+/// interface.
+///
+/// SPI bus access is protected by ATOMIC_BLOCK_START and ATOMIC_BLOCK_END, which will ensure interrupts 
+/// are disabled during access.
+/// 
+/// The read and write routines implement commonly used SPI conventions: specifically that the MSB
+/// of the first byte transmitted indicates that it is a write and the remaining bits indicate the rehgister to access)
+/// This can be overriden 
+/// in subclasses if necessaryor an alternative class, RHNRFSPIDriver can be used to access devices like 
+/// Nordic NRF series radios, which have different requirements.
+///
+/// Application developers are not expected to instantiate this class directly: 
+/// it is for the use of Driver developers.
+class RHSPIDriver : public RHGenericDriver
+{
+public:
+    /// Constructor
+    /// \param[in] slaveSelectPin The controler pin to use to select the desired SPI device. This pin will be driven LOW
+    /// during SPI communications with the SPI device that uis iused by this Driver.
+    /// \param[in] spi Reference to the SPI interface to use. The default is to use a default built-in Hardware interface.
+    RHSPIDriver(PINS slaveSelectPin, RHGenericSPI& spi = hardware_spi);
+
+    /// Initialise the Driver transport hardware and software.
+    /// Make sure the Driver is properly configured before calling init().
+    /// \return true if initialisation succeeded.
+    bool init();
+
+    /// Reads a single register from the SPI device
+    /// \param[in] reg Register number
+    /// \return The value of the register
+    uint8_t        spiRead(uint8_t reg);
+
+    /// Writes a single byte to the SPI device
+    /// \param[in] reg Register number
+    /// \param[in] val The value to write
+    /// \return Some devices return a status byte during the first data transfer. This byte is returned.
+    ///  it may or may not be meaningfule depending on the the type of device being accessed.
+    uint8_t           spiWrite(uint8_t reg, uint8_t val);
+
+    /// Reads a number of consecutive registers from the SPI device using burst read mode
+    /// \param[in] reg Register number of the first register
+    /// \param[in] dest Array to write the register values to. Must be at least len bytes
+    /// \param[in] len Number of bytes to read
+    /// \return Some devices return a status byte during the first data transfer. This byte is returned.
+    ///  it may or may not be meaningfule depending on the the type of device being accessed.
+    uint8_t           spiBurstRead(uint8_t reg, uint8_t* dest, uint8_t len);
+
+    /// Write a number of consecutive registers using burst write mode
+    /// \param[in] reg Register number of the first register
+    /// \param[in] src Array of new register values to write. Must be at least len bytes
+    /// \param[in] len Number of bytes to write
+    /// \return Some devices return a status byte during the first data transfer. This byte is returned.
+    ///  it may or may not be meaningfule depending on the the type of device being accessed.
+    uint8_t           spiBurstWrite(uint8_t reg, const uint8_t* src, uint8_t len);
+
+protected:
+    /// Reference to the RHGenericSPI instance to use to trasnfer data with teh SPI device
+    RHGenericSPI&       _spi;
+
+    /// The pin number of the Slave Selct pin that is used to select the desired device.   
+#if (RH_PLATFORM == RH_PLATFORM_MBED)
+    DigitalOut             _slaveSelectPin;
+#else
+    uint8_t             _slaveSelectPin;
+#endif
+};
+
+#endif