ardupilot/libraries/AP_RPM/RPM_Pin.cpp

112 lines
4.0 KiB
C++

/*
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <AP_HAL/AP_HAL.h>
#include "RPM_Pin.h"
#include <AP_HAL/GPIO.h>
#include <GCS_MAVLink/GCS.h>
extern const AP_HAL::HAL& hal;
AP_RPM_Pin::IrqState AP_RPM_Pin::irq_state[RPM_MAX_INSTANCES];
/*
open the sensor in constructor
*/
AP_RPM_Pin::AP_RPM_Pin(AP_RPM &_ap_rpm, uint8_t instance, AP_RPM::RPM_State &_state) :
AP_RPM_Backend(_ap_rpm, instance, _state)
{
}
/*
handle interrupt on an instance
*/
void AP_RPM_Pin::irq_handler(uint8_t pin, bool pin_state, uint32_t timestamp)
{
const uint32_t dt = timestamp - irq_state[state.instance].last_pulse_us;
irq_state[state.instance].last_pulse_us = timestamp;
// we don't accept pulses less than 100us. Using an irq for such
// high RPM is too inaccurate, and it is probably just bounce of
// the signal which we should ignore
if (dt > 100 && dt < 1000*1000) {
irq_state[state.instance].dt_sum += dt;
irq_state[state.instance].dt_count++;
}
}
void AP_RPM_Pin::update(void)
{
if (last_pin != get_pin()) {
// detach from last pin
if (last_pin != (uint8_t)-1 &&
!hal.gpio->detach_interrupt(last_pin)) {
gcs().send_text(MAV_SEVERITY_WARNING, "RPM: Failed to detach from pin %u", last_pin);
// ignore this failure or the user may be stuck
}
irq_state[state.instance].dt_count = 0;
irq_state[state.instance].dt_sum = 0;
// attach to new pin
last_pin = get_pin();
if (last_pin) {
hal.gpio->pinMode(last_pin, HAL_GPIO_INPUT);
if (!hal.gpio->attach_interrupt(
last_pin,
FUNCTOR_BIND_MEMBER(&AP_RPM_Pin::irq_handler, void, uint8_t, bool, uint32_t),
AP_HAL::GPIO::INTERRUPT_RISING)) {
gcs().send_text(MAV_SEVERITY_WARNING, "RPM: Failed to attach to pin %u", last_pin);
}
}
}
if (irq_state[state.instance].dt_count > 0) {
float dt_avg;
// disable interrupts to prevent race with irq_handler
void *irqstate = hal.scheduler->disable_interrupts_save();
dt_avg = irq_state[state.instance].dt_sum / irq_state[state.instance].dt_count;
irq_state[state.instance].dt_count = 0;
irq_state[state.instance].dt_sum = 0;
hal.scheduler->restore_interrupts(irqstate);
const float scaling = ap_rpm._params[state.instance].scaling;
float maximum = ap_rpm._params[state.instance].maximum;
float minimum = ap_rpm._params[state.instance].minimum;
float quality = 0;
float rpm = scaling * (1.0e6 / dt_avg) * 60;
float filter_value = signal_quality_filter.get();
state.rate_rpm = signal_quality_filter.apply(rpm);
if ((maximum <= 0 || rpm <= maximum) && (rpm >= minimum)) {
if (is_zero(filter_value)){
quality = 0;
} else {
quality = 1 - constrain_float((fabsf(rpm-filter_value))/filter_value, 0.0, 1.0);
quality = powf(quality, 2.0);
}
state.last_reading_ms = AP_HAL::millis();
} else {
quality = 0;
}
state.signal_quality = (0.1 * quality) + (0.9 * state.signal_quality);
}
// assume we get readings at at least 1Hz, otherwise reset quality to zero
if (AP_HAL::millis() - state.last_reading_ms > 1000) {
state.signal_quality = 0;
state.rate_rpm = 0;
}
}