Marlin_Firmware/Marlin/src/HAL/HAL_LPC1768/LPC1768_Servo.cpp

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/**
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* Marlin 3D Printer Firmware
* Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
*
* Based on Sprinter and grbl.
* Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
*
* 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/>.
*
*/
/**
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* Based on servo.cpp - Interrupt driven Servo library for Arduino using 16 bit
* timers- Version 2 Copyright (c) 2009 Michael Margolis. All right reserved.
*/
/**
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* A servo is activated by creating an instance of the Servo class passing the desired pin to the attach() method.
* The servos are pulsed in the background using the value most recently written using the write() method
*
* Note that analogWrite of PWM on pins associated with the timer are disabled when the first servo is attached.
* Timers are seized as needed in groups of 12 servos - 24 servos use two timers, 48 servos will use four.
*
* The methods are:
*
* Servo - Class for manipulating servo motors connected to Arduino pins.
*
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* attach(pin) - Attach a servo motor to an i/o pin.
* attach(pin, min, max) - Attach to a pin, setting min and max values in microseconds
* Default min is 544, max is 2400
*
* write() - Set the servo angle in degrees. (Invalid angles over MIN_PULSE_WIDTH are treated as µs.)
* writeMicroseconds() - Set the servo pulse width in microseconds.
* move(pin, angle) - Sequence of attach(pin), write(angle), delay(SERVO_DELAY).
* With DEACTIVATE_SERVOS_AFTER_MOVE it detaches after SERVO_DELAY.
* read() - Get the last-written servo pulse width as an angle between 0 and 180.
* readMicroseconds() - Get the last-written servo pulse width in microseconds.
* attached() - Return true if a servo is attached.
* detach() - Stop an attached servo from pulsing its i/o pin.
*
*/
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/**
* The only time that this library wants physical movement is when a WRITE
* command is issued. Before that all the attach & detach activity is solely
* within the data base.
*
* The PWM output is inactive until the first WRITE. After that it stays active
* unless DEACTIVATE_SERVOS_AFTER_MOVE is enabled and a MOVE command was issued.
*/
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#include "../../inc/MarlinConfig.h"
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#if HAS_SERVOS && defined(TARGET_LPC1768)
#include "LPC1768_PWM.h"
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#include "LPC1768_Servo.h"
#include "servo_private.h"
ServoInfo_t servo_info[MAX_SERVOS]; // static array of servo info structures
uint8_t ServoCount = 0; // the total number of attached servos
#define US_TO_PULSE_WIDTH(p) p
#define PULSE_WIDTH_TO_US(p) p
#define TRIM_DURATION 0
#define SERVO_MIN() MIN_PULSE_WIDTH // minimum value in uS for this servo
#define SERVO_MAX() MAX_PULSE_WIDTH // maximum value in uS for this servo
Servo::Servo() {
if (ServoCount < MAX_SERVOS) {
this->servoIndex = ServoCount++; // assign a servo index to this instance
servo_info[this->servoIndex].pulse_width = US_TO_PULSE_WIDTH(DEFAULT_PULSE_WIDTH); // store default values - 12 Aug 2009
}
else
this->servoIndex = INVALID_SERVO; // too many servos
}
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int8_t Servo::attach(const int pin) {
return this->attach(pin, MIN_PULSE_WIDTH, MAX_PULSE_WIDTH);
}
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int8_t Servo::attach(const int pin, const int min, const int max) {
if (this->servoIndex >= MAX_SERVOS) return -1;
if (pin > 0) servo_info[this->servoIndex].Pin.nbr = pin; // only assign a pin value if the pin info is
// greater than zero. This way the init routine can
// assign the pin and the MOVE command only needs the value.
this->min = MIN_PULSE_WIDTH; //resolution of min/max is 1 uS
this->max = MAX_PULSE_WIDTH;
servo_info[this->servoIndex].Pin.isActive = true;
return this->servoIndex;
}
void Servo::detach() {
servo_info[this->servoIndex].Pin.isActive = false;
}
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void Servo::write(int value) {
if (value < MIN_PULSE_WIDTH) { // treat values less than 544 as angles in degrees (valid values in microseconds are handled as microseconds)
value = map(constrain(value, 0, 180), 0, 180, SERVO_MIN(), SERVO_MAX());
// odd - this sets zero degrees to 544 and 180 degrees to 2400 microseconds but the literature says
// zero degrees should be 500 microseconds and 180 should be 2500
}
this->writeMicroseconds(value);
}
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void Servo::writeMicroseconds(int value) {
// calculate and store the values for the given channel
byte channel = this->servoIndex;
if (channel < MAX_SERVOS) { // ensure channel is valid
// ensure pulse width is valid
value = constrain(value, SERVO_MIN(), SERVO_MAX()) - (TRIM_DURATION);
value = US_TO_PULSE_WIDTH(value); // convert to pulse_width after compensating for interrupt overhead - 12 Aug 2009
servo_info[channel].pulse_width = value;
LPC1768_PWM_attach_pin(servo_info[this->servoIndex].Pin.nbr, MIN_PULSE_WIDTH, MAX_PULSE_WIDTH, this->servoIndex);
LPC1768_PWM_write(servo_info[this->servoIndex].Pin.nbr, value);
}
}
// return the value as degrees
int Servo::read() { return map(this->readMicroseconds() + 1, SERVO_MIN(), SERVO_MAX(), 0, 180); }
int Servo::readMicroseconds() {
return (this->servoIndex == INVALID_SERVO) ? 0 : PULSE_WIDTH_TO_US(servo_info[this->servoIndex].pulse_width) + TRIM_DURATION;
}
bool Servo::attached() { return servo_info[this->servoIndex].Pin.isActive; }
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void Servo::move(const int value) {
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constexpr uint16_t servo_delay[] = SERVO_DELAY;
static_assert(COUNT(servo_delay) == NUM_SERVOS, "SERVO_DELAY must be an array NUM_SERVOS long.");
if (this->attach(0) >= 0) { // notice the pin number is zero here
this->write(value);
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delay(servo_delay[this->servoIndex]);
#if ENABLED(DEACTIVATE_SERVOS_AFTER_MOVE)
this->detach();
LPC1768_PWM_detach_pin(servo_info[this->servoIndex].Pin.nbr); // shut down the PWM signal
LPC1768_PWM_attach_pin(servo_info[this->servoIndex].Pin.nbr, MIN_PULSE_WIDTH, MAX_PULSE_WIDTH, this->servoIndex); // make sure no one else steals the slot
#endif
}
}
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#endif // HAS_SERVOS && TARGET_LPC1768