Adds function for building default SPI settings so that SPI can be used

library.properties

@@ -1,5 +1,5 @@
 name=SparkFun MMC5983MA Magnetometer Arduino Library
-version=1.0.1
+version=1.0.2
 author=SparkFun Electronics
 maintainer=SparkFun Electronics
 sentence=A I2C/SPI library for the MMC5983MA magnetic compass sensor.

src/SparkFun_MMC5983MA_IO.cpp

@@ -25,13 +25,36 @@ bool SFE_MMC5983MA_IO::begin(TwoWire &i2cPort)
     return isConnected();
 }
 
+void SFE_MMC5983MA_IO::initSPISettings()
+{
+    // CPOL = 1, CPHA = 1 : SPI Mode 3 according to datasheet
+    //  In practice SPI_MODE0 is what worked.
+    _mmcSpiSettings = SPISettings(2000000, MSBFIRST, SPI_MODE0);
+}
+
 bool SFE_MMC5983MA_IO::begin(const uint8_t csPin, SPIClass &spiPort)
 {
     useSPI = true;
     _csPin = csPin;
     digitalWrite(_csPin, HIGH);
     pinMode(_csPin, OUTPUT);
     _spiPort = &spiPort;
+
+    initSPISettings();
+
+    return isConnected();
+}
+
+bool SFE_MMC5983MA_IO::begin(const uint8_t csPin, SPISettings userSettings, SPIClass &spiPort)
+{
+    useSPI = true;
+    _csPin = csPin;
+    digitalWrite(_csPin, HIGH);
+    pinMode(_csPin, OUTPUT);
+    _spiPort = &spiPort;
+
+    _mmcSpiSettings = userSettings;
+
     return isConnected();
 }
 
@@ -40,10 +63,12 @@ bool SFE_MMC5983MA_IO::isConnected()
     bool result = false;
     if (useSPI)
     {
+        _spiPort->beginTransaction(_mmcSpiSettings);
         digitalWrite(_csPin, LOW);
         _spiPort->transfer(READ_REG(PROD_ID_REG));
         uint8_t readback = _spiPort->transfer(DUMMY);
         digitalWrite(_csPin, HIGH);
+        _spiPort->endTransaction();
         result = (readback == PROD_ID);
     }
     else
@@ -59,10 +84,12 @@ void SFE_MMC5983MA_IO::writeMultipleBytes(const uint8_t registerAddress, uint8_t
 {
     if (useSPI)
     {
+        _spiPort->beginTransaction(_mmcSpiSettings);
         digitalWrite(_csPin, LOW);
         _spiPort->transfer(registerAddress);
         _spiPort->transfer(buffer, packetLength);
         digitalWrite(_csPin, HIGH);
+        _spiPort->endTransaction();
     }
     else
     {
@@ -79,10 +106,12 @@ void SFE_MMC5983MA_IO::readMultipleBytes(const uint8_t registerAddress, uint8_t
 {
     if (useSPI)
     {
+        _spiPort->beginTransaction(_mmcSpiSettings);
         digitalWrite(_csPin, LOW);
         _spiPort->transfer(READ_REG(registerAddress));
         _spiPort->transfer(buffer, packetLength);
         digitalWrite(_csPin, HIGH);
+        _spiPort->endTransaction();
     }
     else
     {
@@ -101,10 +130,12 @@ uint8_t SFE_MMC5983MA_IO::readSingleByte(const uint8_t registerAddress)
     uint8_t result = 0;
     if (useSPI)
     {
+        _spiPort->beginTransaction(_mmcSpiSettings);
         digitalWrite(_csPin, LOW);
         _spiPort->transfer(READ_REG(registerAddress));
         result = _spiPort->transfer(DUMMY);
         digitalWrite(_csPin, HIGH);
+        _spiPort->endTransaction();
     }
     else
     {
@@ -121,10 +152,12 @@ void SFE_MMC5983MA_IO::writeSingleByte(const uint8_t registerAddress, const uint
 {
     if (useSPI)
     {
+        _spiPort->beginTransaction(_mmcSpiSettings);
         digitalWrite(_csPin, LOW);
         _spiPort->transfer(registerAddress);
         _spiPort->transfer(value);
         digitalWrite(_csPin, HIGH);
+        _spiPort->endTransaction();
     }
     else
     {
@@ -158,4 +191,4 @@ bool SFE_MMC5983MA_IO::isBitSet(const uint8_t registerAddress, const uint8_t bit
 bool SFE_MMC5983MA_IO::spiInUse()
 {
     return useSPI;
-}
+}

src/SparkFun_MMC5983MA_IO.h

@@ -22,51 +22,59 @@
 class SFE_MMC5983MA_IO
 {
 private:
-    SPIClass* _spiPort = nullptr;
-    uint8_t _csPin = 0;
-    TwoWire *_i2cPort = nullptr;
-    uint8_t _address = 0;
-    bool useSPI = false;
+  SPIClass *_spiPort = nullptr;
+  uint8_t _csPin = 0;
+  SPISettings _mmcSpiSettings;
+
+  TwoWire *_i2cPort = nullptr;
+  uint8_t _address = 0;
+  bool useSPI = false;
 
 public:
-    // Default empty constructor.
-    SFE_MMC5983MA_IO() = default;
+  // Default empty constructor.
+  SFE_MMC5983MA_IO() = default;
+
+  // Default empty destructor
+  ~SFE_MMC5983MA_IO() = default;
+
+  // Builds default SPI settings if none are provided.
+  void initSPISettings();
 
-    // Default empty destructor
-    ~SFE_MMC5983MA_IO() = default;
+  // Configures and starts the I2C I/O layer.
+  bool begin(TwoWire &wirePort);
 
-    // Configures and starts the I2C I/O layer.
-    bool begin(TwoWire &wirePort);
+  // Configures and starts the SPI I/O layer.
+  bool begin(const uint8_t csPin, SPIClass &spiPort = SPI);
 
-    // Configures and starts the SPI I/O layer.
-    bool begin(const uint8_t csPin, SPIClass& spiPort = SPI);
+  // Configures the SPI I/O layer with the given chip select and SPI settings provided by the user.
+  bool begin(const uint8_t csPin, SPISettings userSettings, SPIClass &spiPort = SPI);
 
-    // Returns true if we get the correct product ID from the device.
-    bool isConnected();
+  // Returns true if we get the correct product ID from the device.
+  bool isConnected();
 
-    // Read a single uint8_t from a register.
-    uint8_t readSingleByte(const uint8_t registerAddress);
+  // Read a single uint8_t from a register.
+  uint8_t readSingleByte(const uint8_t registerAddress);
 
-    // Writes a single uint8_t into a register.
-    void writeSingleByte(const uint8_t registerAddress, const uint8_t value);
+  // Writes a single uint8_t into a register.
+  void writeSingleByte(const uint8_t registerAddress, const uint8_t value);
 
-    // Reads multiple bytes from a register into buffer uint8_t array.
-    void readMultipleBytes(const uint8_t registerAddress, uint8_t* const buffer , const uint8_t packetLength);
+  // Reads multiple bytes from a register into buffer uint8_t array.
+  void readMultipleBytes(const uint8_t registerAddress, uint8_t *const buffer, const uint8_t packetLength);
 
-    // Writes multiple bytes to register from buffer uint8_t array.
-    void writeMultipleBytes(const uint8_t registerAddress, uint8_t* const buffer, const uint8_t packetLength);
+  // Writes multiple bytes to register from buffer uint8_t array.
+  void writeMultipleBytes(const uint8_t registerAddress, uint8_t *const buffer, const uint8_t packetLength);
 
-    // Sets a single bit in a specific register. Bit position ranges from 0 (lsb) to 7 (msb).
-    void setRegisterBit(const uint8_t registerAddress, const uint8_t bitMask);
+  // Sets a single bit in a specific register. Bit position ranges from 0 (lsb) to 7 (msb).
+  void setRegisterBit(const uint8_t registerAddress, const uint8_t bitMask);
 
-    // Clears a single bit in a specific register. Bit position ranges from 0 (lsb) to 7 (msb).
-    void clearRegisterBit(const uint8_t registerAddress, const uint8_t bitMask);
+  // Clears a single bit in a specific register. Bit position ranges from 0 (lsb) to 7 (msb).
+  void clearRegisterBit(const uint8_t registerAddress, const uint8_t bitMask);
 
-    // Returns true if a specific bit is set in a register. Bit position ranges from 0 (lsb) to 7 (msb).
-    bool isBitSet(const uint8_t  registerAddress, const uint8_t bitMask);
+  // Returns true if a specific bit is set in a register. Bit position ranges from 0 (lsb) to 7 (msb).
+  bool isBitSet(const uint8_t registerAddress, const uint8_t bitMask);
 
-    // Returns true if the interface in use is SPI
-    bool spiInUse();
+  // Returns true if the interface in use is SPI
+  bool spiInUse();
 };
 
-#endif
+#endif