Migrate MCP and utilities to CircuitPython, including color GIF and volume fixes

circuitpython/lib/battery_cp.py

@@ -0,0 +1,42 @@
+"""CircuitPython Battery Monitor utility.
+
+Wraps analogio.AnalogIn to read voltage via a 2x divider and estimate capacity.
+"""
+
+import analogio
+import board
+
+class BatteryMonitor:
+    def __init__(self, pin=board.IO9):
+        self.adc = analogio.AnalogIn(pin)
+
+    def read_voltage(self):
+        try:
+            # AnalogIn value is 16-bit (0-65535). Map to 3.3V reference.
+            # Divider is 2x, so actual voltage is scale * 2.
+            raw = self.adc.value
+            voltage = (raw / 65535.0) * 3.3 * 2.0
+            return round(voltage, 3)
+        except Exception as e:
+            print(f"Error reading battery ADC: {e}")
+            return None
+
+    def read_percentage(self):
+        voltage = self.read_voltage()
+        if voltage is None:
+            return 0
+        v_min = 3.0
+        v_max = 4.2
+        if voltage <= v_min:
+            return 0
+        if voltage >= v_max:
+            return 100
+        pct = (voltage - v_min) / (v_max - v_min) * 100.0
+        return int(pct)
+
+    def get_status_summary(self):
+        v = self.read_voltage()
+        p = self.read_percentage()
+        if v is None:
+            return "Battery: Error"
+        return f"Battery: {v:.2f}V ({p}%)"