OnOffController

This is sample implementation of On Off controller(bang bang controller) for microcontrollers Arduino, STM32 etc... Visit repository at: https://github.com/watchdoge256/On-OffController

Principle of operation

/**************************************************************
*                    ^Signal value                            *
*                    |                                        *
*                    |                                        *
*                    |                                        *
*                    |           X                            *
*                 +----------------------------------------+  *
*   hysteresis up ^  |         X   X           X              *
*                 v  |        X     X         X               *
*          target +----------------------------------------+  *
*                 ^  |      X         X     X                 *
* hysteresis down v  |     X           X   X                  *
*                 +----------------------------------------+  *
*                    |   X               X                    *
*                    |  X                                     *
*                    | X                                      *
*                    |X                                       *
*                    -------------------------------------->  *
*                                                       time  *
***************************************************************/

Library Usage

The following code depicts the library basic usage, input and output functions should be provided by end user.

#include "onoffcore.h"

static int signal = 10;
static int change = -1;
void turnOnCB(void)
{
  change = 1;
}

void turnOFFcb(void)
{
  change = -1;
}

int main(void)
{
  // controller initial settings
  onoffcore_set_ON_callback(turnOnCB);
  onoffcore_set_OFF_callback(turnOFFcb);
  onoffcore_set_target(15);
  onoffcore_set_hist_up(5);
  onoffcore_set_hist_down(5);

  while(1){
    // in normal circumstances this function will be called by any interrupt, i.e. ADC reading done
    onoffcore_set_signal(signal);
    
    // this task need to be called periodically i.e. 1ms( could be implemented as OS task.
    onoffcore_run();
    signal+=change;
  }
  return 0;
}

API:

onoffcore_set_target

this function sets target value which controller tries to achieve returns: 0- status success

onoffcore_set_hist_down

this function sets down tolerance values for controller returns: 0- status success

onoffcore_set_hist_up

this function sets upper tolerance range for controller returns: 0- status success

onoffcore_set_signal

this function sets actual value of signal to controller logic returns: 0- status success

onoffcore_set_ON_callback

this function will be called when signal drops bellow hysteresis_down returns: 0- status success

onoffcore_set_OFF_callback

this function will be called when signal exceeds hysteresis_up returns: 0- status success

onoffcore_read_target

this function returns programmed target value returns: 0- status success

onoffcore_read_hist_down

this function returns down tolerance value for controller returns: 0- status success

onoffcore_read_hist_up

this function returns tolerance value for controller returns: 0- status success

onoffcore_read_signal

this function returns value controller sees as signal value at the moment returns: 0- status success

onoffcore_run

this function runs controller logic, this has to be called periodically(i.e. each 1ms)

Tags: #DIY, #Arduino, #STM32, #bangbang, #microcontrollers, #C, #library, #onoff