Step 1
Step 2
Step 3
Software Connection
Step 1
Step 2
Step 3
Step 4
Step 5

Published January 10, 2020 © MIT

Using Magnetic to Measure Angle Changes

This demonstrates how to use the Grove - 12 bit Magnetic Rotary Position Sensor(AS5600) to accurately measure angle changes.

BeginnerProtip30 minutes6,386

Things used in this project

Hardware components

Seeed Studio Grove - 12 bit Magnetic Rotary Position Sensor(AS5600)

Seeed Studio Seeeduino V4.2

Software apps and online services

Arduino IDE

Hand tools and fabrication machines

Laser cutter (generic)

Story

The Grove - AS5600 is a programmable 12-bit high-resolution contactless magnetic rotary position sensor. The Grove - AS5600 can work as a magnetic potentialmeter or a magnetic encoder with excellent realiability and durability.

Compared with the traditional potentialmeter/encoder, the Grove - AS5600 has significant advantages: high precision, non-contact, no rotation angle limitation. All those advantages making it suitable for non-contact angle measurement applications, such as the robot arm, tripod head, moter closed-loop control, machine tool axis postioning.

Feature

Non-contact, no rotation angle limitation
12-bit high-resolution, 4096 positions per round
Grove I2C, PWM/Analog Output
Great flexibility on angular excursion: Maximum angle programmable from 18° up to 360°

Specification

Supply voltage: 3.3V / 5V
Operating ambient temperature: -40 – 125℃
Input Current: -100-100mA
Flexibility: Maximum angle programmable from 18°-360°
Interface: I2C(Default I2C Address: 0x36) & Non-Changeable
Output: Analog/PWM output
Output Resolution: 12-bit DAC

Working Principle

Grove - AS5600 is based on the Hall Effect, the build-in Hall sensor can detect changes in the direction of the magnetic field, thus there is also no rotation angle limit. The magnetic field direction information is amplified by the amplifier, with the help of the build-in 12-bit A/D, the AS5600 module can output 4096 positions per round. The output is selectable, you can either use the I2C interface to output the RAW data or output the PWM wave/Analog wave via the OUT pin. Meanwhile, the maximum anlgle is also programmable, you can set the maximum angle from 18° to 360°, which means that the measured angular accuracy is up to 18/4096.

The AS5600 has certain requirements for the magnetic field to be measured. Please use a magnet similar in size to the chip. The module should be measured as close as possible to the magnetic field and the AS5600 sensor center should be aligned with the center of the magnetic field. The vertical distance is preferably from 0.5 mm to 3 mm.

Hardware Overview

Getting Started

HardwareConnection

Step 1

Connect the Grove - 12-bit Magnetic Rotary Position Sensor / Encoder (AS5600) to the I2C port of the Base Shield.

Step 2

Plug Grove - Base Shield into Seeduino.

Step 3

Connect the Seeeduino to PC via a USB cable.

Software Connection

Step 1

Download the AS5600 Library from Github.

Step 2

Restart the Arduino IDE. Open readAngle example via the path: File → Examples → Seeed_AS5600-master → readAngle. Through this demo, we can read the angles from a magnet underneath the sensor.

Step 3

Upload the demo. If you do not know how to upload the code, please check How to upload code.

Step 4

Open the Serial Monitor of Arduino IDE by click Tool-> Serial Monitor. Or tap the ctrl+shift+m key at the same time. Set the baud rate to 115200.

Step 5

The result should be like this when it detected magnet underneath the sensor!

Note: A calibrator is used here. The Calibrator 2D file is listed in Resources, so feel free to download and laser cut yourself!

Code

readAngle.ino

#include <Wire.h>
#include <AS5600.h>
#ifdef ARDUINO_SAMD_VARIANT_COMPLIANCE
  #define SERIAL SerialUSB
  #define SYS_VOL   3.3
#else
  #define SERIAL Serial
  #define SYS_VOL   5
#endif

AMS_5600 ams5600;

int ang, lang = 0;

void setup()
{
  SERIAL.begin(115200);
  Wire.begin();
  SERIAL.println(">>>>>>>>>>>>>>>>>>>>>>>>>>> ");
  if(ams5600.detectMagnet() == 0 ){
    while(1){
        if(ams5600.detectMagnet() == 1 ){
            SERIAL.print("Current Magnitude: ");
            SERIAL.println(ams5600.getMagnitude());
            break;
        }
        else{
            SERIAL.println("Can not detect magnet");
        }
        delay(1000);
    }
  }
}
/*******************************************************
/* Function: convertRawAngleToDegrees
/* In: angle data from AMS_5600::getRawAngle
/* Out: human readable degrees as float
/* Description: takes the raw angle and calculates
/* float value in degrees.
/*******************************************************/
float convertRawAngleToDegrees(word newAngle)
{
  /* Raw data reports 0 - 4095 segments, which is 0.087 of a degree */
  float retVal = newAngle * 0.087;
  ang = retVal;
  return ang;
}
void loop()
{
    SERIAL.println(String(convertRawAngleToDegrees(ams5600.getRawAngle()),DEC));
}

Credits

Seeed

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Seeed R&D Team

Using Magnetic to Measure Angle Changes