Diff: as5048spi.h

Revision:

0:5a1830df0b66

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/as5048spi.h	Tue Oct 08 14:59:11 2019 +0000
@@ -0,0 +1,85 @@
+#include "mbed.h"
+typedef enum {
+    AS_FLAG_PARITY = 0x8000,
+    AS_FLAG_READ = 0x4000,
+} As5048Flag;
+
+typedef enum {
+    AS_CMD_NOP = 0x0000,
+    AS_CMD_ERROR = 0x0001 | AS_FLAG_READ,       // Reads error register of sensor and clear error flags
+    AS_CMD_DIAGNOSTICS = 0x3FFD |  AS_FLAG_READ, // Reads automatic gain control and diagnostics info
+    AS_CMD_MAGNITUDE = 0x3FFE | AS_FLAG_READ,
+    
+    AS_CMD_ANGLE = 0x3FFF| AS_FLAG_PARITY | AS_FLAG_READ,
+} As5048Command;
+
+// Masks for bits in the result of the AS_CMD_DIAGNOSTICS command
+typedef enum {
+    AS_DIAG_CORDIC_OVERFLOW = 0x0200,
+    AS_DIAG_HIGH_MAGNETIC = 0x0400,
+    AS_DIAG_LOW_MAGNETIC = 0x0800,
+} As5048Diagnostics;
+
+
+//! Class for interfacing with the AMS AS5048A magnetic rotary sensor over the SPI-interface.
+class As5048Spi
+{
+public:
+    As5048Spi(PinName mosi, PinName miso, PinName sclk, PinName chipselect, int nDevices = 1);
+    ~As5048Spi();
+    
+    bool error(int device = -1);
+    
+    /// Sets the SPI clock frequency in Hz. Maximum tested frequency is 10MHz.
+    void frequency(int frequency = 1000000);
+    
+    /// Sends a read command to the sensor.
+    const int* read(As5048Command command);
+    
+    /// Sends a read command to the sensor. 
+    /// A call to this function will not directly return the requested value. The
+    /// requested value will be returned in a next read_sequential call. 
+    /// Use this function to read sensor values with minimum speed impact on SPI-bus
+    /// and microcontroller.
+    const int* read_sequential(As5048Command command);
+    
+    /// Performs a single angle measurement on all sensors
+    /// @return Array of raw angle data. To get the 14-bit value representing
+    ///     the angle, apply the mask() to the result.
+    const int* read_angle();
+    
+    /// Performs sequential angle measurements on all sensors. The first time this
+    /// method is called the result is not usefull, the measurement data of the call
+    /// will be returned by the next call to this method.
+    /// @return Array of raw angle data. To get the 14-bit value representing
+    ///     the angle, apply the mask() to the result.
+    const int* read_angle_sequential();
+
+    /// Returns lowest 14-bits
+    static int mask(int sensor_result);
+
+    /// Applies the mask to the first n bytes in the read buffer (for daisychained sensors).
+    static void mask(int* sensor_results, int n);
+    
+    /// Checks if the return value from the sensor has the right parity
+    /// @return true if ok
+    static bool parity_check(int sensor_result);
+    
+    /// Returns an angle from 0 to 36000 (degrees times 100).
+    /// @param sensor_result is one of the values returned by read_angle or read_angle_sequential
+    static int degrees(int sensor_result);
+    
+    /// Returns an angle from 0 to 2*PI*100 
+    /// @param sensor_result is one of the values returned by read_angle or read_angle_sequential
+    static int radian(int sensor_result);
+    
+
+protected:
+    int _nDevices;
+    DigitalOut _chipSelectN;
+    SPI _spi;
+    
+    int* _readBuffer; // Stores the results of the last sequential read
+    
+    int* _read(As5048Command command);
+};