control_modes.pde

Link to the code: control_modes.pde

This file contains funtions for reading the input modes and stablising the selected mode.

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

static void read_control_switch()
{

    uint8_t switchPosition = readSwitch();

...

The first function is read_control_switch. This function read the switch position.

    // If switchPosition = 255 this indicates that the mode control channel input was out of range
    // If we get this value we do not want to change modes.
    if(switchPosition == 255) return;

    if (hal.scheduler->millis() - failsafe.last_valid_rc_ms > 100) {
        // only use signals that are less than 0.1s old.
        return;
    }
    ...

If the switch position is in the correct range there is a check done for the signals used.

    // we look for changes in the switch position. If the
    // RST_SWITCH_CH parameter is set, then it is a switch that can be
    // used to force re-reading of the control switch. This is useful
    // when returning to the previous mode after a failsafe or fence
    // breach. This channel is best used on a momentary switch (such
    // as a spring loaded trainer switch).
    if (oldSwitchPosition != switchPosition ||
        (g.reset_switch_chan != 0 &&
         hal.rcin->read(g.reset_switch_chan-1) > RESET_SWITCH_CHAN_PWM)) {

        set_mode((enum mode)modes[switchPosition].get());

        oldSwitchPosition = switchPosition;
        prev_WP = current_loc;

        // reset speed integrator
        g.pidSpeedThrottle.reset_I();
    }

}

...

After all that, if the new position of the switch is different from the previous one the mode is changed through set_modefunction to the current position.Also the speed integrator is reset.

static uint8_t readSwitch(void){
    uint16_t pulsewidth = hal.rcin->read(g.mode_channel - 1);
    if (pulsewidth <= 900 || pulsewidth >= 2200)     return 255;    // This is an error condition
    if (pulsewidth > 1230 && pulsewidth <= 1360)     return 1;
    if (pulsewidth > 1360 && pulsewidth <= 1490)     return 2;
    if (pulsewidth > 1490 && pulsewidth <= 1620)     return 3;
    if (pulsewidth > 1620 && pulsewidth <= 1749)     return 4;    // Software Manual
    if (pulsewidth >= 1750)                         return 5;    // Hardware Manual
    return 0;
}

...

The readSwitchfunction read the position of the switch using the pulsewidth.

static void reset_control_switch()
{
    oldSwitchPosition = 0;
    read_control_switch();
}
...

This function reset the Switch position to 0.

#define CH_7_PWM_TRIGGER 1800
...

Defines the channel 7 for pwm input.

// read at 10 hz
// set this to your trainer switch
static void read_trim_switch()
{
    switch ((enum ch7_option)g.ch7_option.get()) {
    case CH7_DO_NOTHING:
        break;
    case CH7_SAVE_WP:
        if (channel_learn->radio_in > CH_7_PWM_TRIGGER) {
            // switch is engaged
            ch7_flag = true;
        } else { // switch is disengaged
            if (ch7_flag) {
                ch7_flag = false;

                if (control_mode == MANUAL) {
                    hal.console->println_P(PSTR("Erasing waypoints"));
                    // if SW7 is ON in MANUAL = Erase the Flight Plan
                    mission.clear();
                    if (channel_steer->control_in > 3000) {
                        // if roll is full right store the current location as home
                        init_home();
                    }
                    return;
                } else if (control_mode == LEARNING || control_mode == STEERING) {
                    // if SW7 is ON in LEARNING = record the Wp

                    // create new mission command
                    AP_Mission::Mission_Command cmd = {};

                    // set new waypoint to current location
                    cmd.content.location = current_loc;

                    // make the new command to a waypoint
                    cmd.id = MAV_CMD_NAV_WAYPOINT;

                    // save command
                    if(mission.add_cmd(cmd)) {
                        hal.console->printf_P(PSTR("Learning waypoint %u"), (unsigned)mission.num_commands());
                    }
                } else if (control_mode == AUTO) {
                    // if SW7 is ON in AUTO = set to RTL
                    set_mode(RTL);
                }
            }
        }
        break;
    }
}
...

This function reads for channel 7.If the option is CH7_SAVE_WP some changes are done depending on the control_mode If the mode is AUTO the mission is erased, and the wp is set as home. If the mode is STEERING or learning the wp is current_locnew value.