Dear folks,
Could not find any resource online, neither in this forum regarding with MT6701 i2c integration, so I have modified MagneticSensorI2C.cpp as below, and everything works like a charm. will make a MR on github sometime whne I have time. Enjoy!
Simply add snippet below at line 19,then you can do the following declaration in main program.
MagneticSensorI2C sensor = MagneticSensorI2C(MT6701_I2C);
#include “MagneticSensorI2C.h”
/** Typical configuration for the 12bit MT6701 magnetic sensor over I2C interface */
MagneticSensorI2CConfig_s MT6701_I2C = {
.chip_address = 0x06,
.bit_resolution = 14,
.angle_register = 0x03,
.data_start_bit = 15
};
Full file:
/** 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
.bit_resolution = 14,
.angle_register = 0xFE,
.data_start_bit = 15
};
/** Typical configuration for the 12bit MT6701 magnetic sensor over I2C interface */
MagneticSensorI2CConfig_s MT6701_I2C = {
.chip_address = 0x06,
.bit_resolution = 14,
.angle_register = 0x03,
.data_start_bit = 15
};
// MagneticSensorI2C(uint8_t _chip_address, float _cpr, uint8_t _angle_register_msb)
// @param _chip_address I2C chip address
// @param _bit_resolution bit resolution of the sensor
// @param _angle_register_msb angle read register
// @param _bits_used_msb number of used bits in msb
MagneticSensorI2C::MagneticSensorI2C(uint8_t _chip_address, int _bit_resolution, uint8_t _angle_register_msb, int _bits_used_msb){
// chip I2C address
chip_address = _chip_address;
// angle read register of the magnetic sensor
angle_register_msb = _angle_register_msb;
// register maximum value (counts per revolution)
cpr = _powtwo(_bit_resolution);
// depending on the sensor architecture there are different combinations of
// LSB and MSB register used bits
// AS5600 uses 0…7 LSB and 8…11 MSB
// AS5048 uses 0…5 LSB and 6…13 MSB
// MT6701 uses 0…5 LSB and 6…13 MSB
// used bits in LSB
lsb_used = _bit_resolution - _bits_used_msb;
// extraction masks
lsb_mask = (uint8_t)( (2 << lsb_used) - 1 );
msb_mask = (uint8_t)( (2 << _bits_used_msb) - 1 );
wire = &Wire;
}
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 = _powtwo(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 );
wire = &Wire;
}
MagneticSensorI2C MagneticSensorI2C::AS5600() {
return {AS5600_I2C};
}
void MagneticSensorI2C::init(TwoWire* _wire){
wire = _wire;
// I2C communication begin
wire->begin();
this->Sensor::init(); // call base class init
}
// Shaft angle calculation
// angle is in radians [rad]
float MagneticSensorI2C::getSensorAngle(){
// (number of full rotations)*2PI + current sensor angle
return ( getRawCount() / (float)cpr) * _2PI ;
}
// function reading the raw counter of the magnetic sensor
int MagneticSensorI2C::getRawCount(){
return (int)MagneticSensorI2C::read(angle_register_msb);
}
// I2C functions
/*
-
Read a register from the sensor
-
Takes the address of the register as a uint8_t
-
Returns the value of the register
*/
int MagneticSensorI2C::read(uint8_t angle_reg_msb) {
// read the angle register first MSB then LSB
byte readArray[2];
uint16_t readValue = 0;
// notify the device that is aboout to be read
wire->beginTransmission(chip_address);
wire->write(angle_reg_msb);
currWireError = wire->endTransmission(false);// read the data msb and lsb
wire->requestFrom(chip_address, (uint8_t)2);
for (byte i=0; i < 2; i++) {
readArray[i] = wire->read();
}// depending on the sensor architecture there are different combinations of
// LSB and MSB register used bits
// AS5600 uses 0…7 LSB and 8…11 MSB
// AS5048 uses 0…5 LSB and 6…13 MSB
// MT6701 uses 0…5 LSB and 6…13 MSB
readValue = ( readArray[1] & lsb_mask );
readValue += ( ( readArray[0] & msb_mask ) << lsb_used );
return readValue;
}
/*
-
Checks whether other devices have locked the bus. Can clear SDA locks.
-
This should be called before sensor.init() on devices that suffer i2c slaves locking sda
-
e.g some stm32 boards with AS5600 chips
-
Takes the sda_pin and scl_pin
-
Returns 0 for OK, 1 for other master and 2 for unfixable sda locked LOW
*/
int MagneticSensorI2C::checkBus(byte sda_pin, byte scl_pin) {pinMode(scl_pin, INPUT_PULLUP);
pinMode(sda_pin, INPUT_PULLUP);
delay(250);if (digitalRead(scl_pin) == LOW) {
// Someone else has claimed master!");
return 1;
}if(digitalRead(sda_pin) == LOW) {
// slave is communicating and awaiting clocks, we are blocked
pinMode(scl_pin, OUTPUT);
for (byte i = 0; i < 16; i++) {
// toggle clock for 2 bytes of data
digitalWrite(scl_pin, LOW);
delayMicroseconds(20);
digitalWrite(scl_pin, HIGH);
delayMicroseconds(20);
}
pinMode(sda_pin, INPUT);
delayMicroseconds(20);
if (digitalRead(sda_pin) == LOW) {
// SDA still blocked
return 2;
}
_delay(1000);
}
// SDA is clear (HIGH)
pinMode(sda_pin, INPUT);
pinMode(scl_pin, INPUT);return 0;
}
motor that I coupled it with:
https://nl.mouser.com/ProductDetail/SparkFun/ROB-20441?qs=1Kr7Jg1SGW9zbyRI9In86Q%3D%3D&mgh=1&utm_id=20333412842&gad_source=1&gclid=CjwKCAjwrvyxBhAbEiwAEg_Kgvi7ptAtE5Rgdw87GJZpCB4Hixt1Yirz6DBIkKL3UqeddUc_MV7O1RoCKwsQAvD_BwE
My setup:
