Arduino Forum

Using Arduino => General Electronics => Topic started by: BrianOBrien on Jan 16, 2013, 01:53 am

Title: Connecting Canon T3 to Arduiono.
Post by: BrianOBrien on Jan 16, 2013, 01:53 am
I want to connect my Arduino to my Canon T3 digital camera.
I've written a program to take time lapse photos...

My question is just to make sure I don't blow things like the arduino or canon up.....

The canon docs say shorting the shutter to ground is all that is required.

Is this connection to the Arduino / Canon Ok?

(http://members.shaw.ca/BrianOBrien/realbasic/schematic.png)
Title: Re: Connecting Canon T3 to Arduiono.
Post by: vwlowen on Jan 16, 2013, 04:56 pm
I'm currently doing something similar with a Nikon and opted to use an opto-isolator to keep the camera's electronics away from my DIY.

I'm using a TLP504A which is a dual opto-isolator so it can do the focus as well.  I'd take a look at this site: http://www.doc-diy.net/photo/remote_pinout/ which shows the pinouts for the remote for various cameras.

I would have thought you'd need to activate the focus as well,  a few hundred milliseconds ahead of the shutter.

(http://vwlowen.co.uk/arduino/camera/shutter-opto.jpg)

John.
Title: Re: Connecting Canon T3 to Arduiono.
Post by: John_S on Jan 16, 2013, 05:35 pm

Is this connection to the Arduino / Canon Ok?

(http://members.shaw.ca/BrianOBrien/realbasic/schematic.png)

That will work fine, but it is not the preferred way. The reason is that camera and arduino are not electrically isolated. If (by chance) you get noise or voltage spikes on the ground wire, that can be passed into the camera.

Optoisolators are preferred for that reason. I like the 4N35 for this purpose. They are good to 3500Vrms isolation (10,000 volts by my calculation) and can be had for $0.29 from tayda (http://www.taydaelectronics.com/4n35-optocouplers-phototransistor-30v-ic.html). A 1K resistor works fine between the Arduino and this optoisolator.

Also, a Nikon needs a focus trigger prior to the shutter trigger. A Canon does not.
Title: Re: Connecting Canon T3 to Arduiono.
Post by: mmcp42 on Jan 16, 2013, 05:58 pm
I think you'll find most cameras need focus AND shutter to be grounded
does depend on model
Title: Re: Connecting Canon T3 to Arduiono.
Post by: John_S on Jan 16, 2013, 09:03 pm
I know a T3i, 60D, and XSi do not need a focus trigger. I would guess a T3 does not either.
Title: Re: Connecting Canon T3 to Arduiono.
Post by: KeithRB on Jan 16, 2013, 09:43 pm
Does the T3 allow for the IR remote? You could also control it that way...
Title: Re: Connecting Canon T3 to Arduiono.
Post by: BrianOBrien on Jan 16, 2013, 10:07 pm

I think you'll find most cameras need focus AND shutter to be grounded
does depend on model


Grounding the signal is what causes the camera to react.  So why would have to be grounded?
Title: Re: Connecting Canon T3 to Arduiono.
Post by: BrianOBrien on Jan 16, 2013, 10:08 pm

Does the T3 allow for the IR remote? You could also control it that way...

That's an interesting idea... No cables.
But wouldn't I need to know what data to transmit by IR?
Title: Re: Connecting Canon T3 to Arduiono.
Post by: marco_c on Jan 16, 2013, 10:58 pm
Point the camera remote at a receiver connected to the Arduino,capture the data stream using the IR library and the just use what you have captured back at the ca,era. No need tomreally understand what it is as it usually looks like a long string of arbitrary 'stuff'.
Title: Re: Connecting Canon T3 to Arduiono.
Post by: BrianOBrien on Jan 16, 2013, 11:01 pm

Point the camera remote at a receiver connected to the Arduino,capture the data stream using the IR library and the just use what you have captured back at the ca,era. No need tomreally understand what it is as it usually looks like a long string of arbitrary 'stuff'.

One would assume that this is a serial data stream, and that there is an associated baud rate, start bits, stop bits, parity etc?
Title: Re: Connecting Canon T3 to Arduiono.
Post by: marco_c on Jan 16, 2013, 11:06 pm
IR has its own standard. There are protocols that are used for these and they have to be tolerant of stray light getting in the way of the message. I captured data from my TV remote and the messages were generally the same but differed slightly in some of the numbers for the same thing.

It does not appear to be what you would expect, but there is definitely a packet format and message protocol, which often depends on the maufacturer.
Title: Re: Connecting Canon T3 to Arduiono.
Post by: John_S on Jan 16, 2013, 11:35 pm
There's a library for that!
http://sebastian.setz.name/arduino/my-libraries/multi-camera-ir-control/
Title: Re: Connecting Canon T3 to Arduiono.
Post by: marco_c on Jan 16, 2013, 11:37 pm
As usual someone else is ahead of the curve :)
Title: Re: Connecting Canon T3 to Arduiono.
Post by: MichaelMeissner on Jan 17, 2013, 12:06 am


Does the T3 allow for the IR remote? You could also control it that way...

That's an interesting idea... No cables.
But wouldn't I need to know what data to transmit by IR?


You should be able to get the control parameters from this site, that records many camera IR sequences: http://sebastian.setz.name/arduino/my-libraries/multi-camera-ir-control/ (http://sebastian.setz.name/arduino/my-libraries/multi-camera-ir-control/)

Another approach is to use a servo to press the shutter button.
Title: Re: Connecting Canon T3 to Arduiono.
Post by: BrianOBrien on Jan 23, 2013, 04:20 am
You know what? I don't think there is an IR Receiver on the Canon T3.
I think there are infrared solutions to control it, but they involve a receiver that is connected to the camera.

Someone correct me if I'm wrong, please.


Title: Re: Connecting Canon T3 to Arduiono.
Post by: el_supremo on Jan 23, 2013, 04:46 am
The T3 manual doesn't mention an IR receiver. Only a wired remote.
It looks to me as though the T3 has a simple 1/8 inch stereo jack which should be easy to connect to. (I have the 50D which isn't as easy to do because it has a non-standard plug).
I believe the jack is similar to what vwlowen showed for his Nikon although Canon might have the shutter and focus as he shows or swapped.
I would recommend that you use optoisolators as he shows. You could probably get away without them but it's an expensive risk to take.

Pete
Title: Re: Connecting Canon T3 to Arduiono.
Post by: BrianOBrien on Jan 23, 2013, 09:43 pm
Agreed. The opto decoupling is safest.

A thought occurs to me.. A simple Photo Resistor may do the trick at the camera side...
I believe the camera just wants the current loop closed...

http://playground.arduino.cc/Learning/PhotoResistor (http://playground.arduino.cc/Learning/PhotoResistor)
Title: Re: Connecting Canon T3 to Arduiono.
Post by: el_supremo on Jan 23, 2013, 10:23 pm
But couldn't the photoresistor then fire on any bright light?

Pete
Title: Re: Connecting Canon T3 to Arduiono.
Post by: BrianOBrien on Jan 23, 2013, 11:07 pm
This Photo-Resistor came packaged with the infra-red diode.....
Title: Re: Connecting Canon T3 to Arduiono.
Post by: BrianOBrien on Jan 30, 2013, 06:49 am
Well this doesn't seem to be working.

Using the MATCHED INFRARED EMITTER AND PHOTOTRANSISTOR DETECTOR (http://www.thesource.ca/estore/product.aspx?language=en-ca&catalog=online&category=Misc_Parts&product=2760142) I thought this would work but no... it's not.

(http://members.shaw.ca/BrianOBrien/ir_tx_rx.png)
Video of the IR emitter emitting but nothing happening at the camera. (http://members.shaw.ca/BrianOBrien/IR_TX_RX.m4v)
Image of the setup Arduino connected to camera by mini jack and wires. (http://members.shaw.ca/BrianOBrien/IR_TX_RX.jpg)

Shorting the red and black wires causes the camera to take an exposure, but the photo-transistor doesn't seem to 'short' the circuit.
Title: Re: Connecting Canon T3 to Arduiono.
Post by: el_supremo on Jan 30, 2013, 04:48 pm
The first thing I'd try is putting the two very close together, preferably with something around them to shield the receiver from ambient radiation but I doubt that it will help. The receiver is probably not seeing enough IR to drive the output hard enough to fire the camera. You could add a transistor on the output to amplify it.
But an optoisolator would work better. It might still require a transistor for the output but it would be more reliable than separate Tx/Rx.

Pete
Title: Re: Connecting Canon T3 to Arduiono.
Post by: BrianOBrien on Feb 01, 2013, 04:00 am
That was the ticket... Having the transmitter face the receiver made it work hunky dorey!
:smiley-red:
Title: Re: Connecting Canon T3 to Arduiono.
Post by: BrianOBrien on Feb 01, 2013, 04:22 am
Code: [Select]
http://www.youtube.com/watch?v=xH4nx3fKoe4&feature=youtu.be