     //  manual drive if available
     steer = iBusInput[0];
     throttle = iBusInput[1];
+    driveModeStr = "RC?";
+  } else {
+    driveModeStr = "NONE";
   }
   
   if (autoSource) {

    //  just drive, without auto.
    steer = iBusInput[0];
    throttle = iBusInput[1];
  }
  else if (lastI2cTime) {
    //  I2C trumps serial
    steer = pwmEmulation.readChannelUs(0);
    throttle = pwmEmulation.readChannelUs(1);
#if GATE_I2C_ON_RC_THROTTLE
    autoSource = true;
#endif

uint16_t serialThrottle;

bool serialEchoEnabled = false;
char const *driveModeStr = "";
float lastReadVoltage;

void read_voltage(uint16_t &v, float &voltage) {
  v = analogRead(PIN_A_VOLTAGE_IN);
