SAMSUNG NX2000 (different trigger than rest of NX series) Trigger from APM/Pixhawk

Hi all,

Some months ago I decided what new camera I will use for my big Hexa. Many many people are using Sony NEX5 cameras for aerial photography. However they a expensive and you need IR Trigger electronics.

I took a look at Samsung NX line and found Jeff Taylor (thanks for the inspiring post) post about triggering them with a simple resistor (not said in that post but I guess you need relays anyway). So I went for it.

I bought a Samsung NX2000 which I must say takes wonderful photos and videos. But Jeff's trigger mechanism did not work in these particular camera. After some trial-error I found that the camera "wants" you to always "focus" before trigger the shutter! No matter the camera setting,  believe me!

So what I have. I have an Autopilot that (in relay mode) outputs 5V(APM) or 3.3V(Pixhawk) for a given period of time (shutter time).

With that signal I have to use relays to create two shorts in NX2000 USB pins. One short between FOCUS pin and GND pin and another short between SHUTTER pin and GND pin.

Samsung NX2000 is quite restrictive in how to short those pins. After more trial - error I discovered the following:

  • SHUTTER and FOCUS pins cannot be permanently connected one each other. Otherwise, no shutter
  • FOCUS has to be shorted to GND some "time" before SHUTTER does. If you short both of them at the same time to GND, you will have a random behaviour. Sometimes it works and sometimes not. This was really annoying as it prevent you to use a double relay to short both pins at the same time

So I decided to built a small circuit to trigger the camera by shorting FOCUS to GND and then (anytime after) SHUTTER to GND

I used what I found at my local electronics store. It maybe done differently!

The circuit for triggering NX2000 receives 5V Vcc, 5V signal (will trigger relays, etc) and GND either from APM or from a 5Vto3.3v level shifter if we use Pixhawk.

Bill of materials:

 - 1x NE555

 - 1x 1uF capacitor

 - 1x 18k resistor

 - 1x 10nF capacitor

 - 2x double micro relay

The mechanism is as follows. Once the signal goes high (5V), it drives the relay ON. This relay has two lines, the first shorts FOCUS and GND. The second allows 5V vcc to go and feed the NE555 timer.

So we have already provided focus to the camera. Now we only have to trigger the shutter.The amount of time that the NE555 takes to boot up is going to be our FOCUS-SHUTTER delay. It is normally 100ns.

Once the NE555 boot up it always sees a short in it input pin. Therefore it puts its output high what drives the second relay.

Once the second relay is activated, a short is created between SHUTTER and GND.

On this point you should have a nice picture taken in the NX2000!!

One thing left to say. If you come from Pixhwak world you need to convert 3.3v signal to 5V.

I used Marco's circuit in this post

As you can see all three boards/circuits are connectable/stackable one each other.

Here you can see the full picture:

The FOCUS-SHUTTER delay may have been done with a RC net but I chose NE555 in case a needed to control delay accurately. However I would have needed another NE555....... 

For Pixhawk connection I connected it to OUT 5 (as 1 to 4 are configured PWM) and Relay mode. 

Some pictures of the process and final result

Bench test:

USB Connector

Everything in a prototype pcb

Already mounted on gimbal with shrinking tube

Views: 6986

Comment by Crady von Pawlak on May 2, 2014 at 10:46am

Clever!  Nicely done.

Comment by Carl Schaefer on May 2, 2014 at 10:47am

Hi Jesus,

Nice work and thanks for the info.

I assume the camera has to auto focus for every shot and presumably taking some time to do so.... do you see a long shutter delay between consecutive shots? What is the fastest you can shoot with this trigger?

Carl

Comment by Jesus A on May 2, 2014 at 11:45am
@Carl
The camera is really fast. I have not tested accurately but I would say one shot per second as a minimum.
Autofocus is really fast although I always use manual focus at infinite. So focus does nothing.

MR60
Comment by Hugues on May 2, 2014 at 12:23pm
Clever guy you are!
What's this NE555 IC?
Comment by Carl Schaefer on May 2, 2014 at 12:44pm

That is good. 1 sec is really nice allowing for a faster moving aircraft while keeping a high level of image overlap.

What gimbal and airframe are you using?

Cheers,

Carl


Developer
Comment by Randy on May 2, 2014 at 4:04pm

Great post!  Love the detail.

Comment by Jesus A on May 4, 2014 at 9:47am
@Hugues
Not so clever Hughes! I really think it would have worked with just a RC net as a delay mechanism for the second relay trigger. And on top of that the NE555 is not used in its normal way (timer). But well at least it works very well and it is "scalable".

@Carl
I am using a tarot t960 with a GrouseHouse gimbal+alexmos. Very nice gimbal.
Comment by Xuvisku on May 14, 2014 at 8:22am

@Jesus A

What lens are you using this samsung?

Thanks!

Comment by Jesus A on May 14, 2014 at 10:00am

@Xuvisku

We are using "pancake" 20mm

Comment by Xuvisku on May 14, 2014 at 12:01pm

@Jesus A

Thank you!
What is the price? The brand is samsung? What about her?
Have you ever tested a 15 mm lens?

Comment

You need to be a member of DIY Drones to add comments!

Join DIY Drones

Groups

Season Two of the Trust Time Trial (T3) Contest 
A list of all T3 contests is here. The current round, the Vertical Horizontal one, is here

© 2019   Created by Chris Anderson.   Powered by

Badges  |  Report an Issue  |  Terms of Service