Merge pull request #20 from owennewo/magnetic_sensor_ma730

Magnetic sensor refactoring and ma70 support

Author: askuric

src/Hardware.h

@@ -0,0 +1,47 @@
+#ifndef HARDWARE_H
+#define HARDWARE_H
+
+
+#include "MagneticSensorSPI.h"
+
+/** Typical configuration for the 14bit AMS AS5147 magnetic sensor over SPI interface */
+MagneticSensorSPIConfig_s AS5147_SPI = {
+  .spi_mode = SPI_MODE1,
+  .clock_speed = 1000000,
+  .bit_resolution = 14,
+  .angle_register = 0xCFFF,
+  .data_start_bit = 13, 
+  .command_rw_bit = 14,
+  .command_parity_bit = 15
+};
+
+/** Typical configuration for the 14bit MonolithicPower MA730 magnetic sensor over SPI interface */
+MagneticSensorSPIConfig_s MA730_SPI = {
+  .spi_mode = SPI_MODE0,
+  .clock_speed = 1000000,
+  .bit_resolution = 14,
+  .angle_register = 0x0000,
+  .data_start_bit = 15, 
+  .command_rw_bit = 0,  // not required
+  .command_parity_bit = 0 // parity not implemented
+};
+
+/** Typical configuration for the 12bit AMS AS5600 magnetic sensor over I2C interface */
+MagneticSensorI2CConfig_s AS5600_I2C = {
+  .chip_address = 0x36,
+  .clock_speed = 1000000,
+  .bit_resolution = 12,
+  .angle_register = 0x0E,
+  .data_start_bit = 11
+};
+
+/** Typical configuration for the 12bit AMS AS5048 magnetic sensor over I2C interface */
+MagneticSensorI2CConfig_s AS5048_I2C = {
+  .chip_address = 0x40,  // highly configurable.  if A1 and A2 are held low, this is probable value
+  .clock_speed = 1000000,
+  .bit_resolution = 14,
+  .angle_register = 0xFE,
+  .data_start_bit = 15
+};
+
+#endif

src/MagneticSensorI2C.cpp

@@ -22,13 +22,35 @@ MagneticSensorI2C::MagneticSensorI2C(uint8_t _chip_address, int _bit_resolution,
   // extraction masks
   lsb_mask = (uint8_t)( (2 << lsb_used) - 1 );
   msb_mask = (uint8_t)( (2 << _bits_used_msb) - 1 );
+  clock_speed = 400000;
+  sda_pin = SDA;
+  scl_pin = SCL;
+
 }
 
+MagneticSensorI2C::MagneticSensorI2C(MagneticSensorI2CConfig_s config){
+  chip_address = config.chip_address; 
+
+  // angle read register of the magnetic sensor
+  angle_register_msb = config.angle_register;
+  // register maximum value (counts per revolution)
+  cpr = pow(2, config.bit_resolution);
+  
+  int bits_used_msb = config.data_start_bit - 7;
+  lsb_used = config.bit_resolution - bits_used_msb;
+  // extraction masks
+  lsb_mask = (uint8_t)( (2 << lsb_used) - 1 );
+  msb_mask = (uint8_t)( (2 << bits_used_msb) - 1 );
+  clock_speed = 400000;
+  sda_pin = SDA;
+  scl_pin = SCL;
+
+}
 
 void MagneticSensorI2C::init(){
 
 	//I2C communication begin
-	Wire.begin();
+	Wire.begin(sda_pin, scl_pin, clock_speed);
 
 	// velocity calculation init
 	angle_prev = 0;

src/MagneticSensorI2C.h

@@ -6,6 +6,13 @@
 #include "FOCutils.h"
 #include "Sensor.h"
 
+struct MagneticSensorI2CConfig_s  {
+  int chip_address;
+  long clock_speed;
+  int bit_resolution;
+  int angle_register;
+  int data_start_bit; 
+};
 
 class MagneticSensorI2C: public Sensor{
  public:
@@ -17,8 +24,15 @@ class MagneticSensorI2C: public Sensor{
      * @param _bits_used_msb number of used bits in msb
      */
     MagneticSensorI2C(uint8_t _chip_address, int _bit_resolution, uint8_t _angle_register_msb, int _msb_bits_used);
-    
 
+    /**
+     * MagneticSensorI2C class constructor
+     * @param config  I2C config
+     */
+    MagneticSensorI2C(MagneticSensorI2CConfig_s config);
+
+    static MagneticSensorI2C AS5600();
+    
     /** sensor initialise pins */
     void init();
 
@@ -40,8 +54,17 @@ class MagneticSensorI2C: public Sensor{
     /** returns 1 because it is the absolute sensor */
     int hasAbsoluteZero() override;
     /** returns 0  maning it doesn't need search for absolute zero */
+
     int needsAbsoluteZeroSearch() override;
+
+    /* the speed of the i2c clock signal */
+    long clock_speed;
+
+    /* the pin used for i2c data */
+    int sda_pin;
 
+    /* the pin used for i2c clock */
+    int scl_pin;
 
   private:
     float cpr; //!< Maximum range of the magnetic sensor

src/MagneticSensorSPI.cpp

@@ -5,29 +5,49 @@
 //  _bit_resolution   sensor resolution bit number
 // _angle_register  - (optional) angle read register - default 0x3FFF
 MagneticSensorSPI::MagneticSensorSPI(int cs, float _bit_resolution, int _angle_register){
-  // chip select pin
+  
   chip_select_pin = cs; 
   // angle read register of the magnetic sensor
   angle_register = _angle_register ? _angle_register : DEF_ANGLE_REGISTAR;
   // register maximum value (counts per revolution)
   cpr = pow(2,_bit_resolution);
-
+  spi_mode = SPI_MODE1;
+  clock_speed = 1000000;
+  bit_resolution = _bit_resolution;
+  
+  command_parity_bit = 15; // for backwards compatibilty
+  command_rw_bit = 14; // for backwards compatibilty
+  data_start_bit = 13; // for backwards compatibilty
+  
 }
 
+MagneticSensorSPI::MagneticSensorSPI(MagneticSensorSPIConfig_s config, int cs){
+  chip_select_pin = cs; 
+  // angle read register of the magnetic sensor
+  angle_register = config.angle_register ? config.angle_register : DEF_ANGLE_REGISTAR;
+  // register maximum value (counts per revolution)
+  cpr = pow(2, config.bit_resolution);
+  spi_mode = config.spi_mode;
+  clock_speed = config.clock_speed;
+  bit_resolution = config.bit_resolution;
+  
+  command_parity_bit = config.command_parity_bit; // for backwards compatibilty
+  command_rw_bit = config.command_rw_bit; // for backwards compatibilty
+  data_start_bit = config.data_start_bit; // for backwards compatibilty
+}
 
 void MagneticSensorSPI::init(){
 	// 1MHz clock (AMS should be able to accept up to 10MHz)
-	settings = SPISettings(1000000, MSBFIRST, SPI_MODE1);
+	settings = SPISettings(clock_speed, MSBFIRST, spi_mode);
 
 	//setup pins
 	pinMode(chip_select_pin, OUTPUT);
-
 
 	//SPI has an internal SPI-device counter, it is possible to call "begin()" from different devices
 	SPI.begin();
 #ifndef ESP_H // if not ESP32 board
 	SPI.setBitOrder(MSBFIRST); // Set the SPI_1 bit order
-	SPI.setDataMode(SPI_MODE1) ;
+	SPI.setDataMode(spi_mode) ;
 	SPI.setClockDivider(SPI_CLOCK_DIV8);
 #endif
 
@@ -77,7 +97,7 @@ float MagneticSensorSPI::getVelocity(){
   float angle_c = getAngle();
   // velocity calculation
   float vel = (angle_c - angle_prev)/Ts;
-  
+
   // save variables for future pass
   angle_prev = angle_c;
   velocity_calc_timestamp = now_us;
@@ -147,35 +167,28 @@ byte MagneticSensorSPI::spiCalcEvenParity(word value){
   * Returns the value of the register
   */
 word MagneticSensorSPI::read(word angle_register){
-	word command = 0b0100000000000000; // PAR=0 R/W=R
-	command = command | angle_register;
-
-	//Add a parity bit on the the MSB
-	command |= ((word)spiCalcEvenParity(command)<<15);
 
-	//Split the command into two bytes
-	byte right_byte = command & 0xFF;
-	byte left_byte = ( command >> 8 ) & 0xFF;
+  word command = angle_register;
 
+  if (command_rw_bit > 0) {
+    command = angle_register | (1 << command_rw_bit);
+  }
+  if (command_parity_bit > 0) {
+   	//Add a parity bit on the the MSB
+  	command |= ((word)spiCalcEvenParity(command) << command_parity_bit);
+  }
 
 #if !defined(_STM32_DEF_) // if not stm chips
   //SPI - begin transaction
   SPI.beginTransaction(settings);
 #endif
-  //SPI - begin transaction
-  //SPI.beginTransaction(settings);
 
   //Send the command
   digitalWrite(chip_select_pin, LOW);
-#ifndef ESP_H // if not ESP32 board
   digitalWrite(chip_select_pin, LOW);
-#endif
-  SPI.transfer(left_byte);
-  SPI.transfer(right_byte);
+  SPI.transfer16(command);
   digitalWrite(chip_select_pin,HIGH);
-#ifndef ESP_H // if not ESP32 board
   digitalWrite(chip_select_pin,HIGH);
-#endif
 
 #if defined( ESP_H ) // if ESP32 board
   delayMicroseconds(50);
@@ -186,18 +199,20 @@ word MagneticSensorSPI::read(word angle_register){
   //Now read the response
   digitalWrite(chip_select_pin, LOW);
   digitalWrite(chip_select_pin, LOW);
-  left_byte = SPI.transfer(0x00);
-  right_byte = SPI.transfer(0x00);
+  word register_value = SPI.transfer16(0x00);
   digitalWrite(chip_select_pin, HIGH);
   digitalWrite(chip_select_pin,HIGH);
 
 #if !defined(_STM32_DEF_) // if not stm chips
   //SPI - end transaction
   SPI.endTransaction();
 #endif
+  
+  register_value = register_value >> (1 + data_start_bit - bit_resolution);  //this should shift data to the rightmost bits of the word
+
+  const static word data_mask = ~(0 >> (16 - bit_resolution));
 
-	// Return the data, stripping the parity and error bits
-	return (( ( left_byte & 0xFF ) << 8 ) | ( right_byte & 0xFF )) & ~0xC000;
+	return register_value & data_mask;  // Return the data, stripping the non data (e.g parity) bits
 }
 
 /**

src/MagneticSensorSPI.h

@@ -8,6 +8,16 @@
 
 #define DEF_ANGLE_REGISTAR 0x3FFF
 
+struct MagneticSensorSPIConfig_s  {
+  int spi_mode;
+  long clock_speed;
+  int bit_resolution;
+  int angle_register;
+  int data_start_bit;
+  int command_rw_bit;
+  int command_parity_bit;
+};
+
 class MagneticSensorSPI: public Sensor{
  public:
     /**
@@ -17,7 +27,12 @@ class MagneticSensorSPI: public Sensor{
      * @param angle_register  (optional) angle read register - default 0x3FFF
      */
     MagneticSensorSPI(int cs, float bit_resolution, int angle_register = 0);
-    
+    /**
+     *  MagneticSensorSPI class constructor
+     * @param config   SPI config
+     * @param cs  SPI chip select pin
+     */
+    MagneticSensorSPI(MagneticSensorSPIConfig_s config, int cs);
 
     /** sensor initialise pins */
     void init();
@@ -40,7 +55,14 @@ class MagneticSensorSPI: public Sensor{
     /** returns 1 because it is the absolute sensor */
     int hasAbsoluteZero() override;
     /** returns 0  maning it doesn't need search for absolute zero */
+
     int needsAbsoluteZeroSearch() override;
+
+    // returns the spi mode (phase/polarity of read/writes) i.e one of SPI_MODE0 | SPI_MODE1 | SPI_MODE2 | SPI_MODE3
+    int spi_mode;
+    
+    /* returns the speed of the SPI clock signal */
+    long clock_speed;
 
 
   private:
@@ -72,6 +94,11 @@ class MagneticSensorSPI: public Sensor{
     // velocity calculation variables
     float angle_prev; //!< angle in previous velocity calculation step
     long velocity_calc_timestamp; //!< last velocity calculation timestamp
+    
+    int bit_resolution; //!< the number of bites of angle data
+    int command_parity_bit; //!< the bit where parity flag is stored in command
+    int command_rw_bit; //!< the bit where read/write flag is stored in command
+    int data_start_bit; //!< the the position of first bit
 
 };
 

src/SimpleFOC.h

@@ -94,5 +94,6 @@ void loop() {
 #include "MagneticSensorAnalog.h"
 #include "HallSensor.h"
 #include "BLDCMotor.h"
+#include "Hardware.h"
 
 #endif