如何使我的代码循环（使用arduino）

Question

I've been working on a project for quite a while now, but on the last phase of it I'm stuck on making my code loop. It runs once and from there on it doesn't make the motors move. I've tried the while and if statements but it still doesn't move every time I ask it to.

What the code is supposed to do is to receive information from a websockets canvas and use that information to see if the dc motor goes forwards or backwards.

Hope to find a solution! :)

#include <AFMotor.h>

int x = -10;
int y = -10;
int b = 0;

AF_DCMotor motor_shoulderx(1);
AF_DCMotor motor_shouldery(2);
AF_DCMotor motor_elbow(3);
AF_DCMotor motor_wrist(4);

void setup() {

    motor_shoulderx.run(RELEASE);
    motor_shouldery.run(RELEASE);
    motor_elbow.run(RELEASE);
    motor_wrist.run(RELEASE);
    Serial.begin(9600);

}

void loop() {

    uint8_t i;

    while(Serial.available()) {

        if (b == 0) {
            x = Serial.read();
            b =1;
        }
        else {
            y = Serial.read();
            b = 0;
        }

        if (x != -10) {

            Serial.println("x is:");
            Serial.println(x);

            if(x > 200) {

                motor_shoulderx.run(FORWARD);

                for (i=0; i<255; i++) {
                    motor_shoulderx.setSpeed(i);
                }

            }
            else {

                motor_shoulderx.run(BACKWARD);

                for (i=255; i!=0; i--) {
                    motor_shoulderx.setSpeed(i);  
                }
            }
        }

        if (y != -10) {

            Serial.println ("y is:");
            Serial.println (y);

            if (y > 200) {

                motor_shouldery.run(FORWARD);

                for (i=0; i<255; i++) {
                    motor_shouldery.setSpeed(i);
                }

                motor_elbow.run(FORWARD);

                for (i=0; i<255; i++) {
                    motor_elbow.setSpeed(i);
                }

                motor_wrist.run(FORWARD); 

                for (i=0; i<255; i++) {
                    motor_wrist.setSpeed(i);
                }
            }
            else {

                motor_shouldery.run(BACKWARD);

                for (i=255; i!=0; i--) {
                    motor_shouldery.setSpeed(i);  
                }

                motor_elbow.run(BACKWARD);

                for (i=255; i!=0; i--) {
                    motor_elbow.setSpeed(i);  
                }

                motor_wrist.run(BACKWARD);  

                for (i=255; i!=0; i--) {
                    motor_wrist.setSpeed(i);  
                }
            }
        }   
    }
}

Answer 1

You have to use another structure. At the moment your mainloop consists of many single for-loops, which were executed sequently. In order to realize a parallel execution (I think that is what you want) you need somethink like this:

int i;

void setup() {
    i=255;
//...
}

void loop() {
     i--;
     motor_shoulderx.setSpeed(i);
     motor_elbow.setSpeed(i);  
     if(i==0)i=255;   
}

If you need more complex logic you can easily realize that with conditions. If you need delays you have to use time-comparing code patterns like this:

unsigned long interval=1000;    // the time we need to wait
unsigned long previousMillis=0; // millis() returns an unsigned long.

void setup() {
//...
}

void loop() {
 if ((unsigned long)(millis() - previousMillis) >= interval) {
 previousMillis = millis();
 // ... 
 }
}
//...

All in all, I think the important thing is that the main loop should not be delayed by the single for-statements. Hope this helps you.