im trying develop small circuit using matlab , arduino.
i want turn led bulb on inside script display output.
but, instead of turning on need keep blinking continuously.
the way know how use infinite loop , thats not need because want script keep running while having blinking led.
can point me in right direction please ?
you cannot run 2 lines of code t time in arduino. arduino has 1 processor can execute 1 line of code @ time. if want make program said have 2 options
- either need program linearly. specify each line of code required in program separately. in case during execution of normal program write code turning on , off linearly need ( blink). difficult when program large, make program more complex , large.
second method obtained here. haven't given code here, demonstrating simultaneous run of several task choose program above site :
// severalthingsatthesametime.ino // expansion of blinkwithoutdelay concept illustrate how script // can appear several things @ same time // sketch following // blinks onboard led (as in blinkwithoutdelay sketch) // blinks 2 external leds (leda , ledb) connected pins 12 , 11. // turns led (buttonled connected pin 10) on or off whenever button // connected pin 7 pressed // sweeps servo (connected pin 5) , forth @ different speeds // 1 leg of each led should connected relevant pin , other leg should connected // resistor of 470 ohms or more , other end of resistor arduino gnd. // if led doesn't light connected wrong way round. // on uno , mega "button" piece of wire inserted pin 7. // touching end of wire moist finger sufficient cause switching action // of course proper press-on-release-off button switch used! // arduino not capable of supplying enough 5v power operate servo // servo should have it's own power supply , power supply ground should // connected arduino ground. // sketch written illustrate few different programming features. // use of many functions short pieces of code. // short pieces of code easier follow , debug // use of variables record state of (e.g. onboardledstate) means // enable different functions determine do. // use of millis() manage timing of activities // definition of numbers used program @ top of sketch // can found if need changed //======================================== // ----------libraries-------------- #include <servo.h> // --------constants (won't change)--------------- const int onboardledpin = 13; // pin numbers leds const int led_a_pin = 12; const int led_b_pin = 11; const int buttonled_pin = 10; const int buttonpin = 7; // pin number button const int servopin = 5; // pin number servo signal const int onboardledinterval = 500; // number of millisecs between blinks const int led_a_interval = 2500; const int led_b_interval = 4500; const int blinkduration = 500; // number of millisecs led's on - 3 leds use const int buttoninterval = 300; // number of millisecs between button readings const int servomindegrees = 20; // limits servo movement const int servomaxdegrees = 150; //------------ variables (will change)--------------------- byte onboardledstate = low; // used record whether leds on or off byte led_a_state = low; // low = off byte led_b_state = low; byte buttonled_state = low; servo myservo; // create servo object control servo int servoposition = 90; // current angle of servo - starting @ 90. int servoslowinterval = 80; // millisecs between servo moves int servofastinterval = 10; int servointerval = servoslowinterval; // initial millisecs between servo moves int servodegrees = 2; // amount servo moves @ each step // changed negative value movement in other direction unsigned long currentmillis = 0; // stores value of millis() in each iteration of loop() unsigned long previousonboardledmillis = 0; // store last time led updated unsigned long previousled_a_millis = 0; unsigned long previousled_b_millis = 0; unsigned long previousbuttonmillis = 0; // time when button press last checked unsigned long previousservomillis = 0; // time when servo last moved //======================================== void setup() { serial.begin(9600); serial.println("starting severalthingsatthesametimerev1.ino"); // know sketch running // set led pins output: pinmode(onboardledpin, output); pinmode(led_a_pin, output); pinmode(led_b_pin, output); pinmode(buttonled_pin, output); // set button pin input pullup resistor ensure defaults high pinmode(buttonpin, input_pullup); myservo.write(servoposition); // sets initial position myservo.attach(servopin); } //======================================== void loop() { // notice none of action happens in loop() apart reading millis() // calls functions have action code currentmillis = millis(); // capture latest value of millis() // equivalent noting time clock // use same time led flashes keep them synchronized readbutton(); // call functions work updateonboardledstate(); updateled_a_state(); updateled_b_state(); switchleds(); servosweep(); } //======================================== void updateonboardledstate() { if (onboardledstate == low) { // if led off, must wait interval expire before turning on if (currentmillis - previousonboardledmillis >= onboardledinterval) { // time up, change state high onboardledstate = high; // , save time when made change previousonboardledmillis += onboardledinterval; // note: previous line alternatively // previousonboardledmillis = currentmillis // style used in blinkwithoutdelay example sketch // adding on interval better way ensure succesive periods identical } } else { // i.e. if onboardledstate high // if led on, must wait duration expire before turning off if (currentmillis - previousonboardledmillis >= blinkduration) { // time up, change state low onboardledstate = low; // , save time when made change previousonboardledmillis += blinkduration; } } } //======================================== void updateled_a_state() { if (led_a_state == low) { if (currentmillis - previousled_a_millis >= led_a_interval) { led_a_state = high; previousled_a_millis += led_a_interval; } } else { if (currentmillis - previousled_a_millis >= blinkduration) { led_a_state = low; previousled_a_millis += blinkduration; } } } //======================================== void updateled_b_state() { if (led_b_state == low) { if (currentmillis - previousled_b_millis >= led_b_interval) { led_b_state = high; previousled_b_millis += led_b_interval; } } else { if (currentmillis - previousled_b_millis >= blinkduration) { led_b_state = low; previousled_b_millis += blinkduration; } } } //======================================== void switchleds() { // code switches leds on , off digitalwrite(onboardledpin, onboardledstate); digitalwrite(led_a_pin, led_a_state); digitalwrite(led_b_pin, led_b_state); digitalwrite(buttonled_pin, buttonled_state); } //======================================== void readbutton() { // reads button state after button interval has elapsed // avoids multiple flashes if button bounces // every time button pressed changes buttonled_state causing led go on or off // notice there no need synchronize use of millis() flashing leds if (millis() - previousbuttonmillis >= buttoninterval) { if (digitalread(buttonpin) == low) { buttonled_state = ! buttonled_state; // changes low if high // , high if low previousbuttonmillis += buttoninterval; } } } //====================================== void servosweep() { // similar servo sweep example except uses millis() rather delay() // nothing happens unless interval has expired // value of currentmillis set in loop() if (currentmillis - previousservomillis >= servointerval) { // time move previousservomillis += servointerval; servoposition = servoposition + servodegrees; // servodegrees might negative if (servoposition <= servomindegrees) { // when servo gets minimum position change interval change speed if (servointerval == servoslowinterval) { servointerval = servofastinterval; } else { servointerval = servoslowinterval; } } if ((servoposition >= servomaxdegrees) || (servoposition <= servomindegrees)) { // if servo @ either extreme change sign of degrees make move other way servodegrees = - servodegrees; // reverse direction // , update position ensure within range servoposition = servoposition + servodegrees; } // make servo move next position myservo.write(servoposition); // , record time when move happened } } //========================================end
the above sketch uses concept in "blink without delay" cause 3 leds blink @ different intervals, fourth led controlled button , servo sweeps , forth @ 2 different speeds. idea demonstrate how different processes can accommodated in same general framework.
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