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as5048a

README.md

AS5048A SimpleFOC driver

While AS5048A absolute position magnetic rotary encoder is supported by the standard MagneticSensorSPI driver included in the base distribution, this AS5048A-specific driver includes some optimisations:

  • access to the other registers of the AS5048A, including the magnitude value which can be used to check the magnet strength, and the diagnostics register
  • access to the error state of the sensor, and ability to clear errors
  • it has a fastMode setting, in which the sensor is sent only 1 command per getAngle() call - the value returned will be from previous getAngle() invocation

Hardware setup

Connect as per normal for your SPI bus. No special hardware setup is needed to use this driver.

Software setup

Its actually easier to use than the standard SPI sensor class, because it is less generic:

#include "Arduino.h"
#include "Wire.h"
#include "SPI.h"
#include "SimpleFOC.h"
#include "SimpleFOCDrivers.h"
#include "encoders/as5048a/MagneticSensorAS5048A.h"

#define SENSOR1_CS 5 // some digital pin that you're using as the nCS pin
MagneticSensorAS5048A sensor1(SENSOR1_CS);


void setup() {
    sensor1.init();
}

Set some options:

MagneticSensorAS5048A sensor1(SENSOR1_CS, true, mySPISettings);

Use another SPI bus:

void setup() {
    sensor1.init(SPI2);
}

Here's how you can use it:

    // update the sensor (only needed if using the sensor without a motor)
    sensor1.update();

    // get the angle, in radians, including full rotations
    float a1 = sensor1.getAngle();

    // get the velocity, in rad/s - note: you have to call getAngle() on a regular basis for it to work
    float v1 = sensor1.getVelocity();

    // get the angle, in radians, no full rotations
    float a2 = sensor1.getCurrentAngle();

    // get the raw 14 bit value
    uint16_t raw = sensor1.readRawAngle();

    // read the CORDIC magnitude value, a measure of the magnet field strength
    float m1 = sensor1.readMagnitude();

    // check for errors
    if (sensor1.isErrorFlag()) {
        AS5048Error error = sensor1.clearErrorFlag();
        if (error.parityError) { // also error.framingError, error.commandInvalid
            // etc...            
        }
    }

    // get diagnostics
    AS5048Diagnostics diagnostics = sensor1.readDiagnostics();

PreciseMagneticSensorAS5048A

This is a variant of the sensor that uses PreciseAngle to represent the angle, allowing a (much) greater range of rotation.