Arduino PID in Manual Mode?

i'd use arduino pid library controls, need synchronize manually.

what have continually monitored analog input i'm manually averaging, , upon digital input change, locks average input pid, , i'd @ point, , @ point calculate pid output based on error.

basically, since need synchronize updates output, i'm worried automatic running pid end going haywire derivative , integral gain when thinks winding output doing nothing input, resulting in railing.

what expect i'll have pid controller has "setsampletime" ignored , instead sequential datapoints stored in controller manually added. happen?

so like:

code: [select]


#include <pid_v1.h>

double input, output, setpoint, inputavg;
pid mypid(&input, &output, &setpoint, 1.0, 0.05, 0.25, direct);
float timeconstant 0.01;

void setup() {

  // give setpoint target input of 100.
  setpoint = 100;

  // set "manual" (whatever means).
  mypid.setmode(manual);
}

void loop() {

  // running average of analog input a0.
  inputavg = inputavg*(1-timeconstant) + analogread(a0)*timeconstant;

  // if digital pin goes high, , update pid output.
  // let's pretend magical input goes high 1 loop,
  // in practice i'll doing interrupt setting flag on positive edge.

  if (digitalread(0) == high) {

    // double buffered average put input.
    input = inputavg;

    // pid calculates error , determines new output.
    mypid.compute();

    // manually send out new output. pretend function works.
    analogwrite((unsigned int)output);
  }
}


pid supposed monitor input , compare setpoint, , automatically make adjustments. not sound want. so, forget pid.

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