How to update sensor values at different rates

问题:

I'm working on an arduino project that reads in data from different sensors. I take the values and store them in an array. The problem is that I'd like to update the sensor values at different rates. For example, I wan't to update one every 250ms but another every 50ms. But I'd like it to the loop running in between sensor updates. The only way I can think of getting it to kind of work is with delays but that stops the loop.

回答1:

You can use the millis() function with intervals set for each of the sensors you want to read. Have a look at the Blink Without Delay example on the Arduino website

http://arduino.cc/en/Tutorial/BlinkWithoutDelay

回答2:

If you've got a bunch of sensors to check, you may save a bit of coding by using the Metro library. Same general concept as BRM's answer. You can also use timer interrupts as well. For information with links to a number of articles on timer interrupts, see my Move now, don’t delay() blog post.

回答3:

If you don not want to use a library you could implement it like that:

typedef void (*command)();

template <unsigned long wait_ms, command c>
void repeat() {
    static unsigned long start = millis();
    if (millis()-start >= wait_ms) {
        start += wait_ms;
        c();
    }
}

void task1() {
    // every 50ms
}

void task2() {
    // every 250ms
}

void setup() {
}


void loop() {
    repeat< 50, task1>();
    repeat<250, task2>();  
}

This will work as long as there is nothing that "blocks" inside the loop.