File size: 3,432 Bytes
69c3cbe | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 | #if defined(ARDUINO_ARCH_MBED)
#include <Arduino.h>
#include <Servo.h>
#include <mbed.h>
#if defined __has_include
# if __has_include ("pinDefinitions.h")
# include "pinDefinitions.h"
# endif
#endif
class ServoImpl {
mbed::DigitalOut *pin;
mbed::Timeout timeout; // calls a callback once when a timeout expires
mbed::Ticker ticker; // calls a callback repeatedly with a timeout
public:
ServoImpl(PinName _pin) {
pin = new mbed::DigitalOut(_pin);
}
~ServoImpl() {
ticker.detach();
timeout.detach();
delete pin;
}
void start(uint32_t duration_us) {
duration = duration_us;
ticker.attach(mbed::callback(this, &ServoImpl::call), 0.02f);
}
void call() {
timeout.attach(mbed::callback(this, &ServoImpl::toggle), duration / 1e6);
toggle();
}
void toggle() {
*pin = !*pin;
}
int32_t duration = -1;
};
static ServoImpl* servos[MAX_SERVOS]; // static array of servo structures
uint8_t ServoCount = 0; // the total number of attached servos
#define SERVO_MIN() (MIN_PULSE_WIDTH - this->min) // minimum value in us for this servo
#define SERVO_MAX() (MAX_PULSE_WIDTH - this->max) // maximum value in us for this servo
#define TRIM_DURATION 15 //callback overhead (35 us) -> 15 us if toggle() is called after starting the timeout
Servo::Servo()
{
if (ServoCount < MAX_SERVOS) {
this->servoIndex = ServoCount++;
} else {
this->servoIndex = INVALID_SERVO; // too many servos
}
}
uint8_t Servo::attach(int pin)
{
return this->attach(pin, MIN_PULSE_WIDTH, MAX_PULSE_WIDTH);
}
uint8_t Servo::attach(int pin, int min, int max)
{
pinMode(pin, OUTPUT); // set servo pin to output
servos[this->servoIndex] = new ServoImpl(digitalPinToPinName(pin));
this->min = (MIN_PULSE_WIDTH - min);
this->max = (MAX_PULSE_WIDTH - max);
return this->servoIndex;
}
void Servo::detach()
{
delete servos[this->servoIndex];
servos[this->servoIndex] = NULL;
}
void Servo::write(int value)
{
// treat values less than 544 as angles in degrees (valid values in microseconds are handled as microseconds)
if (value < MIN_PULSE_WIDTH)
{
if (value < 0)
value = 0;
else if (value > 180)
value = 180;
value = map(value, 0, 180, SERVO_MIN(), SERVO_MAX());
}
writeMicroseconds(value);
}
void Servo::writeMicroseconds(int value)
{
if (!servos[this->servoIndex]) {
return;
}
// calculate and store the values for the given channel
byte channel = this->servoIndex;
if( (channel < MAX_SERVOS) ) // ensure channel is valid
{
if (value < SERVO_MIN()) // ensure pulse width is valid
value = SERVO_MIN();
else if (value > SERVO_MAX())
value = SERVO_MAX();
value = value - TRIM_DURATION;
if (servos[this->servoIndex]->duration == -1) {
servos[this->servoIndex]->start(value);
}
servos[this->servoIndex]->duration = value;
}
}
int Servo::read() // return the value as degrees
{
return map(readMicroseconds(), SERVO_MIN(), SERVO_MAX(), 0, 180);
}
int Servo::readMicroseconds()
{
if (!servos[this->servoIndex]) {
return 0;
}
return servos[this->servoIndex]->duration;
}
bool Servo::attached()
{
return servos[this->servoIndex] != NULL;
}
#endif
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