Another USB shutter question... - page 3 - General Help and Assistance on using CHDK stable releases - CHDK Forum  

Another USB shutter question...

  • 28 Replies
  • 7081 Views
Re: Another USB shutter question...
« Reply #20 on: 08 / September / 2009, 15:13:29 »
Advertisements

*

Offline CMC68

  • *
  • 20
Re: Another USB shutter question...
« Reply #21 on: 08 / September / 2009, 15:19:32 »
That's fantastic thank you so much. I have some breadboard so I'll go down that route, get it going then all being well I can make it more permanent when I have it working (and climbed further up my very steep learning curve).

The grey cable that goes out of shot, is that connected to the USB plug for the camera?

Chris

Re: Another USB shutter question...
« Reply #22 on: 08 / September / 2009, 15:41:26 »
The grey cable that goes out of shot, is that connected to the USB plug for the camera?

Yes.
V+ is at top of board, ground at bottom.

You cannot see all the resistor connections but I think you will be able to work it out.



David

*

Offline CMC68

  • *
  • 20
Re: Another USB shutter question...
« Reply #23 on: 16 / September / 2009, 14:10:32 »
Hi David,

Finally managed to get some peace and quiet (small child, new puppy and various other interruptions) and have built the circuit (I think).

Not 100% on where the resistors go but what I have done is:

Left Transistor
C -> Ground
B -> Ground via n/o switch & -> Middle transistor Emitter via 22K Resistor
E -> Middle transistor base

Middle Transistor
C -> Ground
B -> Left Transistor Emitter via 22K resistor
E -> Left Transistor Base via 22K resistor & to V+ via 270 Resistor and LED

Right Transistor
C -> Ground
B -> Ground via 1K8 Resistor & -> V+ via n/o switch then 2K2 resistor
E -> Middle Transistor Base

Pic attached for reference. I'm aware I have left the resistor tails a little long but didn't want to trim them until I was sure they were in the right place.

On powering it up the LED comes on (with 5.68v at the USB plug), the right hand switch turns it off (and only off - and removes the reading at the USB plug) and the left hand turns it back on (and only on) is that what would be expected?

have I got it right!!!.



Re: Another USB shutter question...
« Reply #24 on: 16 / September / 2009, 16:58:55 »
have I got it right!!!.

Yes, well done .. do not shoot the puppy   :)

Next test ...

Power-up the circuit and turn the LED off.

Plug USB into camera and power-up the camera.

Press switch to turn-on your circuit LED.
Camera screen should blank and camera blue LED light.
Turn-off your circuit LED, photo should be take.
If you do not turn-off your circuit LED a photo will be taken anyway after about ten seconds.


David

*

Offline CMC68

  • *
  • 20
Re: Another USB shutter question...
« Reply #25 on: 18 / September / 2009, 05:39:54 »
That's amazing it actually works!

I have to leave a small delay between the first and second switch push (about a second or so) for the screen to blank and the blue light on the camera to come on (transfer/print - I'm on a A720IS). And as you say, leave it for 10 secs and it fires anyway (out of interest is this time delay selectable/variable in SDM?)

Now I don't want to get ahead of myself but is the next step to replace the second switch with the output from my flash trigger?

Chris

Re: Another USB shutter question...
« Reply #26 on: 18 / September / 2009, 15:01:55 »
eave it for 10 secs and it fires anyway (out of interest is this time delay selectable/variable in SDM?)
No, you cannot make it much longer, the camera would crash (presumably due to a 'watchdog' timer in the Canon firmware).

Quote
is the next step to replace the second switch with the output from my flash trigger?


Certainly is  :)

Looking at this diagram, VOUT on CONN1 goes high at same time as flash trigger.

At present, you are using a switch to apply a positive voltage to transistor 3 base to turn it on.

Connect VOUT to the base and connect the controller ground to USB V- wire.

Setup the camera and bistable as before, press the switch to blank the screen.

Now, trigger your controller.

It should take a photo.

It will NOT be synchronised with any flash connected to the controller, we can discuss that later.

Let us know how you get on.


David
« Last Edit: 18 / September / 2009, 15:21:35 by Microfunguy »

*

Offline CMC68

  • *
  • 20
Re: Another USB shutter question...
« Reply #27 on: 30 / September / 2009, 08:56:43 »
Absolutely fantastic.

Nothing seems to be happening quickly around here at the moment but I have finally replaced the second switch with the feed from the Quake trigger and it works  :D :D

Managed a couple of very basic test shots and everything is working as expected. I need to do some more experimenting, particularly to assess the delay, and also to make sure I am setting the SDM side correctly for high speed shutter (my very quick test shots were bleached out with on-camera flash even at an shutter override of 1/40000 - which I would not have expected).

I also need to draw out the circuit diagram (for reference), make it more tidy and solid (by transferring it to stripboard - I'll need the circuit diagram for when I get this wrong!) and mounting it in an enclosure.

Light-wise, going forward, I plan to use the on-board flash to trigger slaves on a combination of my two 283s and Nikon SB600 as the situation requires it. As long as I can get 1/30000 or better as a shutter speed, the flash duration can be greater (in fact, slower shutter faster flash - sync'd might be interesting too). But now I have the ability to fire the shutter on cue I can have ambient light which allows new situations I couldn't shoot before.

Thanks so much for your help David, I could not have done this alone.

Chris


Re: Another USB shutter question...
« Reply #28 on: 30 / September / 2009, 11:33:21 »
Glad it is working !

Contact me directly, I will give you some information that you will be interested in.


David

 

Related Topics