 
 #define LED_PIN 13
 
-// serial input //
+// host communication //
 #define MAX_COMMAND 10
 #define BUF_SIZE 32
 byte buf[BUF_SIZE];

{
  byte pin = bctoi(2, 1);
  if (pin < 0 || pin > 7) { err(); return; }
  unsigned long a;
  a = (unsigned long) analogRead(pin);
  a = a * 5000 / 1024;
  Serial.print("RA");
  Serial.print((unsigned int) pin);
  Serial.print("=");
  Serial.println(a);
}

byte bytes = 0;
byte crc = 0;

// power management //
#define AUX_PIN 7
#define MOTORS_PIN 8
#define UPS_PIN 9
#define BATTERY_PIN 10

// common vars //
unsigned long lastCommandTime;
