Two Way Serial communication with Arduino & Processing
in
Integration and Hardware
•
10 months ago
Hi. I have manage to send the sensor data "tune" to the processing, but when i am trying to send the data back to Arduino,(when "tune" is less than -100, LED on pin 13 lights up, later it will be implemented to a servo action) the reaction time is very slow, and it seems the things are out of sync. I have googled and people said is the buffer problem, but i cannot manage to find a way to sort it out.
Thank you for answering!
Processing
- import processing.serial.*;
- Serial myPort;
- float value;
- int val;
- int state;
- void setup()
- {
- println("COM Ports");
- println(myPort.list());
- println("=========");
- myPort = new Serial(this, Serial.list()[5], 9600);
- }
- void draw()
- {
- }
- void serialEvent(Serial p) {
- // get message till line break (ASCII > 13)
- if ( myPort.available() > 0) {
- // while ( myPort.available() > 0);
- String message = myPort.readStringUntil(13);
- if (message != null) {
- value = float(message);
- // println(value);
- }
- }
- if (value < -100) {
- state=1;
- }
- else {
- state=0;
- }
- myPort.write(state);
- println(state);
- }
Arduino
- /*
- * Therremin with TTL Oscillator 4MHz
- * Timer1 for freauency measurement
- * Timer2 for gate time
- */
- #include <Stdio.h>
- #define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
- #define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
- //! Macro that clears all Timer/Counter1 interrupt flags.
- #define CLEAR_ALL_TIMER1_INT_FLAGS (TIFR1 = TIFR1)
- int pinLed = 13; // LED connected to digital pin 13
- int pinFreq = 5;
- int pinFreq2 = 6;
- int incomingByte;
- void setup()
- {
- pinMode(pinLed, OUTPUT); // sets the digital pin as output
- pinMode(pinFreq, INPUT);
- pinMode(pinFreq2, INPUT);
- pinMode(8, OUTPUT);
- Serial.begin(9600); // connect to the serial port
- // hardware counter setup ( refer atmega168.pdf chapter 16-bit counter1)
- TCCR1A=0; // reset timer/counter1 control register A
- TCCR1B=0; // reset timer/counter1 control register A
- TCNT1=0; // counter value = 0
- // set timer/counter1 hardware as counter , counts events on pin T1 ( arduino pin 5)
- // normal mode, wgm10 .. wgm13 = 0
- sbi (TCCR1B ,CS10); // External clock source on T1 pin. Clock on rising edge.
- sbi (TCCR1B ,CS11);
- sbi (TCCR1B ,CS12);
- // timer2 setup / is used for frequency measurement gatetime generation
- // timer 2 presaler set to 256 / timer 2 clock = 16Mhz / 256 = 62500 Hz
- cbi (TCCR2B ,CS20);
- sbi (TCCR2B ,CS21);
- sbi (TCCR2B ,CS22);
- //set timer2 to CTC Mode
- cbi (TCCR2A ,WGM20);
- sbi (TCCR2A ,WGM21);
- cbi (TCCR2B ,WGM22);
- OCR2A = 124; // CTC at top of OCR2A / timer2 interrupt when coun value reaches OCR2A value
- // interrupt control
- sbi (TIMSK2,OCIE2A); // enable Timer2 Interrupt
- }
- volatile byte i_tics;
- volatile byte f_ready ;
- volatile byte mlt ;
- unsigned int ww;
- int cal;
- int cal_max;
- char st1[32];
- long freq_in;
- long freq_zero;
- long freq_cal;
- unsigned int dds;
- int tune;
- int cnt=0;
- void loop()
- {
- cnt++;
- f_meter_start();
- tune=tune+1;
- while (f_ready==0) { // wait for period length end (100ms) by interrupt
- digitalWrite(8, (dds+=tune) >> 15); // kind of DDS tonegenerator / connect speaker to portb.0 = arduino pin8
- }
- tune = freq_in-freq_zero;
- Serial.println(tune);
- // Initialisation
- if (cnt == 10) {
- freq_zero=freq_in;
- freq_cal=freq_in;
- cal_max=0;
- Serial.print("INITIALISATION");
- }
- // calibration
- if (tune>0) { // try autocalibrate when out of range
- freq_zero=freq_in;
- freq_cal=freq_in;
- cal_max=0;
- Serial.print("CALIBRATION");
- Serial.println("");
- }
- cal = freq_in-freq_cal;
- if ( cal < 0) cal*=-1; // absolute value
- if (cal > cal_max) cal_max=cal;
- // digitalWrite(pinLed,1); // let LED blink
- if ( tune < 0) tune*=-1; // absolute value
- // sprintf(st1, " %04d",tune);
- // digitalWrite(pinLed,0);
- // see if there's incoming serial data:
- if (Serial.available() > 0) {
- // while (Serial.available() > 0)
- incomingByte = Serial.read();
- }
- digitalWrite(pinLed, incomingByte);
- }
- //******************************************************************
- void f_meter_start() {
- f_ready=0; // reset period measure flag
- i_tics=0; // reset interrupt counter
- sbi (GTCCR,PSRASY); // reset presacler counting
- TCNT2=0; // timer2=0
- TCNT1=0; // Counter1 = 0
- cbi (TIMSK0,TOIE0); // dissable Timer0 again // millis and delay
- sbi (TIMSK2,OCIE2A); // enable Timer2 Interrupt
- TCCR1B = TCCR1B | 7; // Counter Clock source = pin T1 , start counting now
- }
- //******************************************************************
- // Timer2 Interrupt Service is invoked by hardware Timer2 every 2ms = 500 Hz
- // 16Mhz / 256 / 125 / 500 Hz
- // here the gatetime generation for freq. measurement takes place:
- ISR(TIMER2_COMPA_vect) {
- if (i_tics==50) { // multiple 2ms = gate time = 100 ms
- // end of gate time, measurement ready
- TCCR1B = TCCR1B & ~7; // Gate Off / Counter T1 stopped
- cbi (TIMSK2,OCIE2A); // disable Timer2 Interrupt
- sbi (TIMSK0,TOIE0); // ensable Timer0 again // millis and delay
- f_ready=1; // set global flag for end count period
- // calculate now frequeny value
- freq_in=0x10000 * mlt; // mukt #ovverflows by 65636
- freq_in += TCNT1; // add counter1 value
- mlt=0;
- }
- i_tics++; // count number of interrupt events
- if (TIFR1 & 1) { // if Timer/Counter 1 overflow flag
- mlt++; // count number of Counter1 overflows
- sbi(TIFR1,TOV1); // clear Timer/Counter 1 overflow flag
- }
- }
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