using arduino to trigger flash a unit? help.

Hi

I have sunpak auto 170, hot-shoe trying to make it trigger using arduino this is my circuit diagram :


my code:

#define CAMERA_FLASH_PIN 4
void setup()
{
  pinMode(CAMERA_FLASH_PIN, OUTPUT);
  digitalWrite(CAMERA_FLASH_PIN, LOW);
  Serial.begin(9600); // open serial
  Serial.println("Press the spacebar to trigger the flash");
}
void loop()
{
  int cmd;

  while (Serial.available() > 0)
  {
    int cmd = Serial.read();
    switch (cmd)
    {
    case ' ':
      {
        digitalWrite(CAMERA_FLASH_PIN, HIGH);
        delay(100);
        digitalWrite(CAMERA_FLASH_PIN, LOW);
        break;
      }
    default:
      {
        Serial.println("Press the spacebar to trigger the flash");
      }
    }
  }
}

I'm pretty sure the flash unit and hot shoe are working, same as the circuit since I used to trigger LED.

Could anyone please assist me? really stuck :frowning:

What is the trigger voltage on the flash?

Have you tried reversing the polarity of the opto-coupler's output?

Or try a MOC2030 opto-triac.

AWOL:
What is the trigger voltage on the flash?
Have you tried reversing the polarity of the opto-coupler's output?
Or try a MOC2030 opto-triac.

Couldn't get it to measure.
I have tried reversing but no hope.

Yes ! MOC2030, looks promising .

the MOC2030 has 5 pins how can I connect ?

also is there much differences between MOC2030 and MOC 3023 and MOC3021 ?

thanks

the MOC2030 has 5 pins how can I connect ?

The ones I have have six pins.

Pins 1 and 3 are the LED, 4 and 6 the output, IIRC.
Datasheets should be online.

If you short pins 3 and 4 does the flash fire ?

AWOL:
What is the trigger voltage on the flash?

160V.

Its an old model for film cameras.

Tht voltage may have damaged the hotshoe adapter.

Pins 1 and 3 are the LED, 4 and 6 the output, IIRC.

Ok will give a try.

If you short pins 3 and 4 does the flash fire ?

Yes ! flash and hot shoe just work together but not with arduino

Next question:

Reverse the wires going to pins 1 & 2.

You may want to put an LED there as well so you can see the output is going high.

Are you sure the delay(100) is long enough?

Just asking.

Good luck.

lost_and_confused:
Next question:
Reverse the wires going to pins 1 & 2.
You may want to put an LED there as well so you can see the output is going high.
Are you sure the delay(100) is long enough?
Just asking.
Good luck.

I have LED and can turn that on ! but not the flash.
Yes.
Thanks

Are you sure the delay(100) is long enough?

I have some 20+ year old Vivitar 283s triggered by MOC2030s.

They'll trigger with a 1us pulse on the opto's LED.

OK, next:

Forget the flash.

Where the flash is now, remove it - totally.

Get a resistor, LED and try this:

+5v… resistor…LED…opto-isolator (in) (out) … ground.

You may have to try reversing the in and out pins.

You will have to increase the delay() time to a few thousand values.

See if the LED glows.

This will confirm the opto is working.

lost_and_confused:
OK, next:
Forget the flash.
Where the flash is now, remove it - totally.
Get a resistor, LED and try this:
+5v...... resistor..........LED..........opto-isolator (in) (out) ......... ground.
You may have to try reversing the in and out pins.
You will have to increase the delay() time to a few thousand values.
See if the LED glows.
This will confirm the opto is working

It works!
but still not the flash :frowning:

@AWOL: Can I use MOC3020/MOC3021 Opto Coupler ?

I don't see why not; I've been using them for years.

Does the flash have a charge light ?

If so what happens when you try to fire using the optocoupler ?

@AWOL: ok gonna try that tomorrow. using same diagram but replacing the opto with moc 3020 , thanks.

Boardburner2:
Does the flash have a charge light ?
If so what happens when you try to fire using the optocoupler ?

Yes, still on and ready, somehow the opto has no effect to the flash-unit somehow.

Try removing the hot shoe and connecting the opto to the pc connector on the back of the flash.

Boardburner2:
Try removing the hot shoe and connecting the opto to the pc connector on the back of the flash.

still no luck, im sure that my opto is not compatible with this flash unit, hopefully MOC2030 will do the tirck

Im totally baffled.

Simply shorting the outputs of the coupler fires the flash, doesn't it?

Thats what he said, also said he could read no voltage present.
I would expect to read something even if its an inaccurate one.