Need help with syntax for a triggering function...

Forum 2005-2010 (read only) Software Syntax & Programs
1

How would I code the syntax to fire the camera shutter every 14 minutes, just in case it's not triggered by lightning during that time period?

#define PIN_STATUS 13
#define PIN_IR_LED 12
#define FREQ 38400  // IR frequence
#define LIGHTNING_TRIGGER_ANALOG_PIN 0
#define TRIGGER_THRESHHOLD 50
 
//shutter sequence (on,off,on,off ... in microsecond)
unsigned long sequence[] = {2000,27830,390,1580,410,3580,400,63200,2000,27830,390,1580,410,3580,400,0};
int seq_l;
int lightningVal;

//oscd is a delay in microsecond used at each oscillation.
int oscd;
 
void oscillate(int pin, unsigned long n, int shine){
    int ir_status=0;
    while(n>0){
        n--;
        delayMicroseconds(oscd);
        ir_status  =  !ir_status; 
        digitalWrite(pin,  ir_status && shine);  
    }
}
 
void snap(){
    int i;
    digitalWrite(PIN_STATUS,  1);  
    for(i=0;i<seq_l;i++){
        oscillate(PIN_IR_LED, sequence[i], i%2==0);
    }
    digitalWrite(PIN_STATUS,  0);
}
 
void setup() {
    lightningVal = analogRead(LIGHTNING_TRIGGER_ANALOG_PIN);
        int min=1, max=100, i;
    int last_oscd=0;
    unsigned long before, intervalle;
    oscd=max;
 
    seq_l = sizeof(sequence)/sizeof(unsigned long);
 
    pinMode(PIN_STATUS, OUTPUT);
    pinMode(PIN_IR_LED, OUTPUT);
    Serial.begin(9600);
 
    //this "while" will process the best "oscd"
    Serial.println("Ready");
    while(last_oscd!=oscd){
        last_oscd=oscd;
        oscd=(min+max)>>1;
 
        before=millis();
        oscillate(PIN_STATUS, FREQ, 1);
        intervalle=millis()-before;
 
        if(intervalle >= 1000) max=oscd;
        else min=oscd;
 
        Serial.print(intervalle);
        Serial.print(" : ");
        Serial.print(min);
        Serial.print("<->");
        Serial.println(max);
    }
 
    Serial.print("oscd: ");
    Serial.println(oscd);
 
    //rewrite the sequence array, we replace all values in microsecond by the number of oscillation
    for(i=0;i<seq_l;i++){
        Serial.print(sequence[i]);
        Serial.print("->");
        sequence[i] = (sequence[i] * FREQ) / (intervalle * 1000);
        Serial.println(sequence[i]);
    }
}
 
 
void loop() {    
    {
  int cmd;
  int newLightningVal = analogRead(LIGHTNING_TRIGGER_ANALOG_PIN);
  Serial.println(lightningVal, DEC);
    
  if (abs(newLightningVal - lightningVal) > TRIGGER_THRESHHOLD)
  {
    snap();
    Serial.println("Shutter triggered");
    //delay(200);
  }

  lightningVal = newLightningVal;
}

}

thank you.....

Jim

2

How would you do it manually? You'd look at your watch, and compare the current time against the time that the shutter was last tripped. If 14 minutes or more had elapsed, you'd trigger the shutter, and note the new last time the shutter was tripped.

So, use millis() to get the current "time", and save the time whenever the shutter is tripped.

On each pass through loop, get the current time, and compare it to the last time.

3

thank you, Paul. I guess this old man's brain didn't have enough caffeine this morning!

It's working fine now...

Jim