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//#include "Energia.h"
#include "Servo.h"
#include "inc/hw_ints.h"
#include "inc/hw_memmap.h"
#include "inc/hw_types.h"
#include "driverlib/debug.h"
#include "driverlib/gpio.h"
#include "driverlib/pin_map.h"
#include "driverlib/rom.h"
#include "driverlib/sysctl.h"
#include "driverlib/timer.h"
#include <stdio.h>
#include <stdlib.h>
/** variables and functions common to all Servo instances **/
volatile unsigned long ticksPerMicrosecond; // Holds the calculated value
unsigned int servoAssignedMask;
static servo_t servos[SERVOS_PER_TIMER];
unsigned int remainderPulseWidth;
volatile int currentServo;
bool servoInitialized = false;
// Calculate the new period remainder
static void calculatePeriodRemainder(void)
{
unsigned long servoPeriodSum = 0;
for (int i = 0; i < SERVOS_PER_TIMER; i++){
servoPeriodSum += servos[i].pulse_width;
}
remainderPulseWidth = REFRESH_INTERVAL - servoPeriodSum;
}
static void initServo(void) {
/* Work around for clock not yet up in the constructor */
#ifdef TARGET_IS_BLIZZARD_RB1
ROM_SysCtlClockSet(SYSCTL_SYSDIV_2_5|SYSCTL_USE_PLL|SYSCTL_XTAL_16MHZ|SYSCTL_OSC_MAIN);
#endif
// Initialize global variables
ticksPerMicrosecond = 0;
servoAssignedMask = 0;
remainderPulseWidth = 0;
currentServo = 0;
for(int i = 0; i < SERVOS_PER_TIMER; i++)
{
servos[i].pin_number = 0;
servos[i].pulse_width = DEFAULT_SERVO_PULSE_WIDTH;
servos[i].enabled = false;
}
calculatePeriodRemainder();
// Enable TIMER
ROM_SysCtlPeripheralEnable(SERVO_TIMER_PERIPH);
// Enable processor interrupts.
ROM_IntMasterEnable();
TimerIntRegister(SERVO_TIMER, SERVO_TIMER_A, ServoIntHandler);
// Configure the TIMER
ROM_TimerConfigure(SERVO_TIMER, SERVO_TIME_CFG);
// Calculate the number of timer counts/microsecond
ticksPerMicrosecond = F_CPU / 1000000;
// Initially load the timer with 20ms interval time
ROM_TimerLoadSet(SERVO_TIMER, SERVO_TIMER_A, ticksPerMicrosecond * REFRESH_INTERVAL);
// Setup the interrupt for the TIMER1A timeout.
ROM_IntEnable(SERVO_TIMER_INTERRUPT);
ROM_TimerIntEnable(SERVO_TIMER, SERVO_TIMER_TRIGGER);
// Enable the timer.
ROM_TimerEnable(SERVO_TIMER, SERVO_TIMER_A);
}
/** end of static functions **/
/*
* When a new servo is created:
* Initialize the servo module if it has not been initialized already.
* Add the servo to the assigned servos mask with a new index.
*/
Servo::Servo()
{
// If the module has not been initialized
if(!servoInitialized)
{
// Initialize it.
initServo();
// It has been initialized, prevent further calls to initServo().
servoInitialized = true;
}
this->index = INVALID_SERVO;
// Look for a free servo index.
for (int i = 0; i < SERVOS_PER_TIMER; i++)
{
if (((servoAssignedMask >> i) & 1) == 0)
{
// Save the index for this instance of Servo.
this->index = i;
// Mark the spot in the mask.
servoAssignedMask |= (1 << i);
// Stop searching for free slots.
break;
}
}
}
//! Write a pulse width of the given number of microseconds to the Servo's pin
void Servo::writeMicroseconds(int value)
{
if(value < this->min) value = this->min;
if(value > this->max) value = this->max;
servos[this->index].pulse_width = value;
calculatePeriodRemainder();
}
//! Write a pulse width of the given degrees (if in the appropriate range to be degrees)
//! or of the specified number of microseconds (if in the appropriate range to be microseconds)
void Servo::write(int value)
{
// treat values less than the min pulse width as angles in degrees (valid values in microseconds are handled as microseconds)
if(value < MIN_SERVO_PULSE_WIDTH)
{
if(value < 0) value = 0;
if(value > 180) value = 180;
value = map(value, 0, 180, this->min, this->max);
}
this->writeMicroseconds(value);
}
//! Returns the current pulse width of the Servo's signal, in microseconds
int Servo::readMicroseconds()
{
return servos[this->index].pulse_width;
}
//! Returns the current position of the Servo, in degrees
int Servo::read() // return the value as degrees
{
return map( this->readMicroseconds()+1, this->min, this->max, 0, 180);
}
//! Attach the Servo to the given pin (and, if specified, with the given range of legal pulse widths)
unsigned int Servo::attach(unsigned int pin, int min, int max)
{
this->min = min;
this->max = max;
servos[this->index].pin_number = pin;
pinMode(pin, OUTPUT);
digitalWrite(pin, LOW);
calculatePeriodRemainder();
servos[this->index].enabled = true;
return this->index;
}
//! Detach the Servo from its pin
void Servo::detach()
{
// Disable, clean up
servos[this->index].enabled = false;
servos[this->index].pulse_width = DEFAULT_SERVO_PULSE_WIDTH;
calculatePeriodRemainder();
digitalWrite(servos[this->index].pin_number, LOW);
}
bool Servo::attached(){
return servos[this->index].enabled;
}
//! ISR for generating the pulse widths
void ServoIntHandler(void)
{
// Clear the timer interrupt.
ROM_TimerIntClear(SERVO_TIMER, SERVO_TIMER_TRIGGER);
// Get the pulse width value for the current servo from the array
// and reload the timer with the new pulse width count value
// if we have already serviced all servos (currentServo = MAX_SERVO_NO)
// then this value should be the 20ms period value
if(currentServo < SERVOS_PER_TIMER)
{
ROM_TimerLoadSet(SERVO_TIMER, SERVO_TIMER_A, ticksPerMicrosecond * servos[currentServo].pulse_width);
}
else
{
ROM_TimerLoadSet(SERVO_TIMER, SERVO_TIMER_A, ticksPerMicrosecond * remainderPulseWidth);
}
// End the servo pulse set previously (if any)
if(currentServo > 0) // If not the 1st Servo....
{
if (servos[currentServo - 1].enabled)
{
digitalWrite(servos[currentServo - 1].pin_number, LOW);
}
}
// Set the current servo pin HIGH
if(currentServo < SERVOS_PER_TIMER)
{
if (servos[currentServo - 1].enabled)
{
digitalWrite(servos[currentServo].pin_number, HIGH);
}
currentServo++; // Advance to next servo for processing next time
}
else
{
currentServo = 0; // Start all over again
}
}
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