本帖最後由 aazz 於 2018-4-27 09:51 編輯
這個程式是否可以更改 頻率來增加速度呢;
typedef unsigned char PROGMEM prog_uchar;
// table of 256 sine values / one sine period / stored in flash memory
PROGMEM prog_uchar const sine256[] = {
127,130,133,136,139,143,146,149,152,155,158,161,164,167,170,173,176,178,181,184,187,190,192,195,198,200,203,205,208,210,212,215,217,219,221,223,225,227,229,231,233,234,236,238,239,240,
242,243,244,245,247,248,249,249,250,251,252,252,253,253,253,254,254,254,254,254,254,254,253,253,253,252,252,251,250,249,249,248,247,245,244,243,242,240,239,238,236,234,233,231,229,227,225,223,
221,219,217,215,212,210,208,205,203,200,198,195,192,190,187,184,181,178,176,173,170,167,164,161,158,155,152,149,146,143,139,136,133,130,127,124,121,118,115,111,108,105,102,99,96,93,90,87,84,81,78,
76,73,70,67,64,62,59,56,54,51,49,46,44,42,39,37,35,33,31,29,27,25,23,21,20,18,16,15,14,12,11,10,9,7,6,5,5,4,3,2,2,1,1,1,0,0,0,0,0,0,0,1,1,1,2,2,3,4,5,5,6,7,9,10,11,12,14,15,16,18,20,21,23,25,27,29,31,
33,35,37,39,42,44,46,49,51,54,56,59,62,64,67,70,73,76,78,81,84,87,90,93,96,99,102,105,108,111,115,118,121,124
};
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
int PWM_OUT_U =11;
int PWM_OUT_V =10;
int PWM_OUT_W = 9;
int LED_PIN =13; // LED status on pin 13
int TEST_PIN =7; // Scope trigger on pin 7
int OFFSET_V =85; // Offset for second-phase
int OFFSET_W =170; // Offset for third-phase
int dfmax =115;
int dfm =1;
int doonce=0;
int analog_val= 0;
double dfreq,dfreq_old;
const double refclk=31372.549 ;
//const double refclk = 31376.6; // measured
const uint64_t twoTo32 = pow(2, 32); // compute value at startup and use as constant
// variables used inside interrupt service declared as voilatile
volatile uint8_t icnt; // var inside interrupt
volatile uint8_t icnt1; // var inside interrupt
volatile uint8_t c4ms; // counter incremented every 4ms
volatile uint32_t phase_accum; // pahse accumulator
volatile uint32_t tword_m; // dds tuning word m
//******************************************************************
void setup()
{
pinMode(LED_PIN, OUTPUT); // sets the digital pin as output
Serial.begin(115200); // connect to the serial port
Serial.println("DDS Test");
pinMode(TEST_PIN, OUTPUT); // sets the digital pin as output
pinMode(PWM_OUT_U, OUTPUT); // PWM output / frequency output
pinMode(PWM_OUT_V, OUTPUT); // PWM output / frequency output
pinMode(PWM_OUT_W, OUTPUT); // PWM output / frequency output
// Setup the timers
setup_timer1();
setup_timer2();
// disable interrupts to avoid timing distortion
cbi (TIMSK0, TOIE0); // disable Timer0 !!! delay() is now not available
sbi (TIMSK2, TOIE2); // enable Timer2 Interrupt
dfreq = 0.0; // initial output frequency = 1000.0 Hz
tword_m = twoTo32 * dfreq / refclk; // calulate DDS new tuning word
}
//******************************************************************
void loop()
{
/*
if (!doonce) {
dfreq=map(analogRead(0),0,1023,0,800);
dfreq_old=dfreq;
}
if(abs(dfreq-dfreq_old )> 10) {
if(dfreq>dfreq_old ) dfreq+=10;
else dfreq-=10;
doonce=1;
} else doonce=0;
/ */
/*
dfmax=map(analogRead(0),0,1023,0,800);
if (dfreq == 0){ dfm = 10;} // run up an down xHz each second
if (dfreq >= dfmax){ dfm = -10;}
dfreq+= dfm;
*/
analog_val=analogRead(0);
dfreq=map(analog_val,0,1023,0,100);
// read Poti on analog pin 0 -- 716 = 4.24V = 103 Hz
if (c4ms > 250) // timer / wait for a full second
{
c4ms = 0;
cbi (TIMSK2, TOIE2); // disble Timer2 Interrupt
tword_m = twoTo32 * dfreq / refclk; // calulate DDS new tuning word
sbi (TIMSK2, TOIE2); // enable Timer2 Interrupt
Serial.print(analog_val);
Serial.print(" ");
Serial.print(dfreq);
Serial.print(" ");
Serial.print(dfmax);
Serial.print(" ");
Serial.println(tword_m);
}
}
//******************************************************************
// timer1 setup
// set prscaler to 1, PWM mode to phase correct PWM, 16000000/512 = 31.25kHz clock
void setup_timer1(void)
{
// Timer1 Clock Prescaler to : 1
sbi (TCCR1B, CS10);
cbi (TCCR1B, CS11);
cbi (TCCR1B, CS12);
// Timer0 PWM Mode set to Phase Correct PWM
cbi (TCCR1A, COM1A0); // clear Compare Match
sbi (TCCR1A, COM1A1);
cbi (TCCR1A, COM1B0); // clear Compare Match
sbi (TCCR1A, COM1B1);
sbi (TCCR1A, WGM10); // Mode 1 / Phase Correct PWM
cbi (TCCR1A, WGM11);
cbi (TCCR1B, WGM12);
cbi (TCCR1B, WGM13);
}
//******************************************************************
// timer2 setup
// set prscaler to 1, PWM mode to phase correct PWM, 16000000/512 = 31.25kHz clock
void setup_timer2()
{
// Timer2 Clock Prescaler to : 1
sbi (TCCR2B, CS20);
cbi (TCCR2B, CS21);
cbi (TCCR2B, CS22);
// Timer2 PWM Mode set to Phase Correct PWM
cbi (TCCR2A, COM2A0); // clear Compare Match
sbi (TCCR2A, COM2A1);
sbi (TCCR2A, WGM20); // Mode 1 / Phase Correct PWM
cbi (TCCR2A, WGM21);
cbi (TCCR2B, WGM22);
}
//******************************************************************
// Timer2 Interrupt Service at 31.25kHz = 32us
// this is the timebase REFCLOCK for the DDS generator
// FOUT = (M (REFCLK)) / (2 exp 32)
// runtime : 8 microseconds ( inclusive push and pop)
ISR(TIMER2_OVF_vect)
{
if (!icnt || icnt==127){
sbi(PORTD, TEST_PIN); // Test / set PORTD,TEST_PIN high to observe timing with a oscope
}
phase_accum += tword_m; // soft DDS, phase accu with 32 bits
icnt = phase_accum >> 24; // use upper 8 bits for phase accu as frequency information
OCR2A = pgm_read_byte_near(sine256 + icnt); // read value fron ROM sine table and send to PWM DAC
OCR1A = pgm_read_byte_near(sine256 + (uint8_t)(icnt + OFFSET_V));
OCR1B = pgm_read_byte_near(sine256 + (uint8_t)(icnt + OFFSET_W));
if (icnt1++ == 125) // increment variable c4ms every 4 milliseconds
{
c4ms++;
icnt1 = 0;
}
if (!icnt || icnt==127){
cbi(PORTD, TEST_PIN); // reset PORTD,TEST_PIN
}
}
https://www.youtube.com/watch?v=r_iyW9dIqqQ
http://wvs-k.weebly.com/sinus-3phase-pwm-arduino.html |
簡體版
訂閱頻道
訂閱電子報
發表於 2018-4-25 11:28
| 
