marlin/Marlin/src/feature/ammeter.cpp

  /**
 * Marlin 3D Printer Firmware
 * Copyright (c) 2021 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
 *
 * Based on Sprinter and grbl.
 * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *
 */

#include "../inc/MarlinConfig.h"

#if ENABLED(I2C_AMMETER)
  #include "ammeter.h"

  INA226 ina;

  Ammeter ammeter;

  float Ammeter::scale;
  float Ammeter::current;

  void Ammeter::init() {
    ina.begin();
    ina.configure(INA226_AVERAGES_16, INA226_BUS_CONV_TIME_1100US, INA226_SHUNT_CONV_TIME_1100US, INA226_MODE_SHUNT_BUS_CONT);
    ina.calibrate(I2C_AMMETER_SHUNT_RESISTOR,I2C_AMMETER_IMAX);
  }

  float Ammeter::read() {
      scale = 1;
      current = ina.readShuntCurrent();
      if (current <= .0001) current = 0;  // Cleanup lsb bit amplification errors
      if (current < .1) scale = 1000; 
      return current * scale;
  }

#endif //I2C_AMMETER