diff --git a/arduino/main/main.ino b/arduino/main/main.ino
index 2ea7c88..f994052 100644
--- a/arduino/main/main.ino
+++ b/arduino/main/main.ino
@@ -1,35 +1,19 @@
-// Vehicle Voltage Monitor
-// Reads 12V-14.4V battery via voltage divider on A0
-// Outputs to Serial for PC monitoring
+// Smart Serow - Main
+// Motorcycle telemetry hub
 
-// Pin definitions
-const int PIN_VBAT = A0;  // Vehicle voltage input (via divider)
-
-// Voltage divider constants
-// Divider: 100k upper (to Vin), 47k lower (to GND)
-// Vout = Vin * (47k / (100k + 47k)) = Vin * 0.3197
-// So Vin = Vout / 0.3197
-// At 12V: ADC sees 3.84V | At 14.4V: ADC sees 4.60V
-const float DIVIDER_RATIO = 47.0 / (100.0 + 47.0);  // ~0.3197
-const float ADC_REF = 5.0;
-const int ADC_MAX = 1023;
+#include "voltage.h"
 
 void setup() {
   Serial.begin(9600);
   pinMode(LED_BUILTIN, OUTPUT);
+
+  voltage_init();
 }
 
 void loop() {
-  // Read and calculate voltage
-  int rawAdc = analogRead(PIN_VBAT);
-  float vDivider = (rawAdc / (float)ADC_MAX) * ADC_REF;
-  float vBattery = vDivider / DIVIDER_RATIO;
-
-  // Output to serial
-  Serial.print("ADC: ");
-  Serial.print(rawAdc);
-  Serial.print(" | V_bat: ");
-  Serial.print(vBattery, 2);
+  // Report battery voltage
+  Serial.print("V_bat: ");
+  Serial.print(voltage_read(), 2);
   Serial.println("V");
 
   // Heartbeat blink
diff --git a/arduino/main/voltage.cpp b/arduino/main/voltage.cpp
new file mode 100644
index 0000000..8dbea2d
--- /dev/null
+++ b/arduino/main/voltage.cpp
@@ -0,0 +1,27 @@
+#include "voltage.h"
+
+// Pin definitions
+static const int PIN_VBAT = A0;
+
+// Voltage divider constants
+// Divider: 100k upper (to Vin), 47k lower (to GND)
+// Vout = Vin * (47k / (100k + 47k)) = Vin * 0.3197
+// At 12V: ADC sees 3.84V | At 14.4V: ADC sees 4.60V
+static const float DIVIDER_RATIO = 47.0 / (100.0 + 47.0);  // ~0.3197
+static const float ADC_REF = 5.0;
+static const int ADC_MAX = 1023;
+
+void voltage_init() {
+  // analogRead doesn't need explicit pinMode, but here for future config
+  // e.g., could switch to internal 1.1V reference for different range
+}
+
+int voltage_read_raw() {
+  return analogRead(PIN_VBAT);
+}
+
+float voltage_read() {
+  int raw = voltage_read_raw();
+  float vDivider = (raw / (float)ADC_MAX) * ADC_REF;
+  return vDivider / DIVIDER_RATIO;
+}
diff --git a/arduino/main/voltage.h b/arduino/main/voltage.h
new file mode 100644
index 0000000..65c6d8a
--- /dev/null
+++ b/arduino/main/voltage.h
@@ -0,0 +1,15 @@
+#ifndef VOLTAGE_H
+#define VOLTAGE_H
+
+#include <Arduino.h>
+
+// Initialize voltage monitoring (call in setup)
+void voltage_init();
+
+// Read battery voltage, returns volts (e.g., 12.5)
+float voltage_read();
+
+// Read raw ADC value (0-1023)
+int voltage_read_raw();
+
+#endif