Add Laser Based I2C Ammeter Feature (#21835)

Marlin/src/feature/ammeter.h

@@ -0,0 +1,44 @@
+/**
+ * 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/>.
+ *
+ */
+#pragma once
+
+#include "../inc/MarlinConfigPre.h"
+
+#include <Wire.h>
+#include <INA226.h>
+
+#ifndef I2C_AMMETER_IMAX    
+  #define I2C_AMMETER_IMAX      .500 // Calibration range 500 Milli Amps
+#endif
+
+class Ammeter {
+private:
+    static float scale;
+
+public:
+    static float current;
+    static void init();
+    static float read();
+ 
+};
+
+extern Ammeter ammeter;