ardupilot/APMrover2/radio.pde

// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-

//Function that will read the radio data, limit servos and trigger a failsafe
// ----------------------------------------------------------------------------
static uint8_t failsafeCounter = 0;		// we wait a second to take over the throttle and send the rover circling


static void init_rc_in()
{
	// set rc channel ranges
	g.channel_steer.set_angle(SERVO_MAX);
	g.channel_throttle.set_angle(100);

	// set rc dead zones
	g.channel_steer.set_dead_zone(60);
	g.channel_throttle.set_dead_zone(6);

	//set auxiliary ranges
	update_aux_servo_function(&g.rc_5, &g.rc_6, &g.rc_7, &g.rc_8);
}

static void init_rc_out()
{
    hal.rcout->enable_ch(CH_1);
    hal.rcout->enable_ch(CH_2);
    hal.rcout->enable_ch(CH_3);
    hal.rcout->enable_ch(CH_4);
    hal.rcout->enable_ch(CH_5);
    hal.rcout->enable_ch(CH_6);
    hal.rcout->enable_ch(CH_7);
    hal.rcout->enable_ch(CH_8);

#if HIL_MODE != HIL_MODE_ATTITUDE
	hal.rcout->write(CH_1, 	g.channel_steer.radio_trim);					// Initialization of servo outputs
	hal.rcout->write(CH_3, 	g.channel_throttle.radio_trim);

	hal.rcout->write(CH_5, 	g.rc_5.radio_trim);
	hal.rcout->write(CH_6, 	g.rc_6.radio_trim);
	hal.rcout->write(CH_7,   g.rc_7.radio_trim);
    hal.rcout->write(CH_8,   g.rc_8.radio_trim);
#else
	hal.rcout->write(CH_1, 	1500);					// Initialization of servo outputs
	hal.rcout->write(CH_2, 	1500);
	hal.rcout->write(CH_3, 	1000);
	hal.rcout->write(CH_4, 	1500);

	hal.rcout->write(CH_5, 	1500);
	hal.rcout->write(CH_6, 	1500);
	hal.rcout->write(CH_7,   1500);
    hal.rcout->write(CH_8,   2000);
#endif

}

static void read_radio()
{
    g.channel_steer.set_pwm(hal.rcin->read(CH_ROLL));

	g.channel_throttle.set_pwm(hal.rcin->read(CH_3));
  	g.rc_5.set_pwm(hal.rcin->read(CH_5));
 	g.rc_6.set_pwm(hal.rcin->read(CH_6));        
	g.rc_7.set_pwm(hal.rcin->read(CH_7));
	g.rc_8.set_pwm(hal.rcin->read(CH_8));

	control_failsafe(g.channel_throttle.radio_in);

	g.channel_throttle.servo_out = g.channel_throttle.control_in;

	if (g.channel_throttle.servo_out > 50) {
        throttle_nudge = (g.throttle_max - g.throttle_cruise) * ((g.channel_throttle.norm_input()-0.5) / 0.5);
	} else {
		throttle_nudge = 0;
	}

	/*
	cliSerial->printf_P(PSTR("OUT 1: %d\t2: %d\t3: %d\t4: %d \n"),
				g.rc_1.control_in,
				g.rc_2.control_in,
				g.rc_3.control_in,
				g.rc_4.control_in);
	*/
}

static void control_failsafe(uint16_t pwm)
{
	if (!g.fs_throttle_enabled) {
        // no throttle failsafe
		return;
    }

	// Check for failsafe condition based on loss of GCS control
	if (rc_override_active) {
		if(millis() - rc_override_fs_timer > FAILSAFE_SHORT_TIME) {
			ch3_failsafe = true;
		} else {
			ch3_failsafe = false;
		}

	//Check for failsafe and debounce funky reads
	} else if (g.fs_throttle_enabled) {
		if (pwm < (unsigned)g.fs_throttle_value){
			// we detect a failsafe from radio
			// throttle has dropped below the mark
			failsafeCounter++;
			if (failsafeCounter == 9){
				gcs_send_text_fmt(PSTR("MSG FS ON %u"), (unsigned)pwm);
			}else if(failsafeCounter == 10) {
				ch3_failsafe = true;
			}else if (failsafeCounter > 10){
				failsafeCounter = 11;
			}

		}else if(failsafeCounter > 0){
			// we are no longer in failsafe condition
			// but we need to recover quickly
			failsafeCounter--;
			if (failsafeCounter > 3){
				failsafeCounter = 3;
			}
			if (failsafeCounter == 1){
				gcs_send_text_fmt(PSTR("MSG FS OFF %u"), (unsigned)pwm);
			}else if(failsafeCounter == 0) {
				ch3_failsafe = false;
			}else if (failsafeCounter <0){
				failsafeCounter = -1;
			}
		}
	}
}

static void trim_control_surfaces()
{
	read_radio();
	// Store control surface trim values
	// ---------------------------------
    if (g.channel_steer.radio_in > 1400) {
		g.channel_steer.radio_trim = g.channel_steer.radio_in;
        // save to eeprom
        g.channel_steer.save_eeprom();
    }
}

static void trim_radio()
{
	for (int y = 0; y < 30; y++) {
		read_radio();
	}
    trim_control_surfaces();
}