Add MAX17048 sensor component and update .gitignore for new files

.gitignore

@@ -15,6 +15,15 @@
 # Whitelist subdirectory yaml files
 !*/*.yaml
 !*/*.yml
+!*/*.md
+!*/*.sh
+!*/*.js*
+!*/*.txt*
+!*/*.json*
+!*/*.ui.yaml
+!*/*.h
+!*/*.py
+
 
 # Whitelist specific folders (uncomment as needed)
 !automations/
@@ -24,7 +33,10 @@
 !esphome/ha-remote/
 !esphome/ha-remote/components/
 !esphome/ha-remote/components/**
-!custom_components/
+!esphome/ha-remote/components/max17043/
+!esphome/components/**
+!esphome/components/max17043/**
+!custom_components/**
 # !packages/
 # !themes/
 # !node-red/

esphome/MAX17048_component.h

@@ -0,0 +1,47 @@
+#include "esphome.h"
+
+#define MAX17048_ADDRESS        0x36
+#define MAX17048_VCELL          0x02 // voltage
+#define MAX17048_SOC            0x04 // percentage
+#define MAX17048_MODE           0x06
+#define MAX17048_VERSION        0x08
+#define MAX17048_CONFIG         0x0c
+#define MAX17048_COMMAND        0xfe
+
+class MAX17048Sensor : public PollingComponent, public Sensor {
+ public:
+  Sensor *voltage_sensor = new Sensor();
+  Sensor *percentage_sensor = new Sensor();
+
+  MAX17048Sensor() : PollingComponent(10000) {}
+
+  void setup() override {
+    // Initialize the device here. Usually Wire.begin() will be called in here,
+    // though that call is unnecessary if you have an 'i2c:' entry in your config
+    ESP_LOGD("custom", "Starting up MAX17048 sensor");
+
+    Wire.begin();
+  }
+
+  uint16_t read16(uint8_t reg) {
+      uint16_t temp;
+      Wire.begin();
+      Wire.beginTransmission(MAX17048_ADDRESS);
+      Wire.write(reg);
+      Wire.endTransmission();
+      Wire.requestFrom(MAX17048_ADDRESS, 2);
+      temp = (uint16_t)Wire.read() << 8;
+      temp |= (uint16_t)Wire.read();
+      Wire.endTransmission();
+      return temp;
+  }
+
+  void update() override {
+    float voltage = (float)(read16(MAX17048_VCELL)) * 78.125 / 1000000;
+    voltage_sensor->publish_state(voltage);
+
+    uint16_t percentage_tmp = read16(MAX17048_SOC);
+    float percentage = (float)(percentage_tmp) / 256;
+    percentage_sensor->publish_state(percentage);
+  }
+};