How can I trigger a camera from an android phone

[scotteyre]

Hi

I have been trying to assemble a simple transistor based camera trigger to work with an app for triggering a camera at set intervals.

From what I have discovered is that the volume does not go loud enough to trigger the transistor to make it switch. It will work on my home stereo with the volume turned up. So How can I boost the volume signal enough to make the transistor work?
On my stereo the threshold to trigger the camera is around 466 with the continuity test and only 17 on the phone

Voltage on the stereo is 0.27 on the 200m DCV setting and the phone is 0.25 same setting
Amps on the stereo are 02 on the 2000μ setting and on the phone 022 on the same setting.

Here is the schematic I followed,http://www.diyphotography.net/building-diy-trigger-trap/
Im using the same npn transistor (BC547) with the base connected to a either a 1k or a 2.2kΩ resistor, tried both as I don't have 1.5kΩ. Im not worried about the focus side of it so I left that out, but that shouldn't make any change.

Does anybody have any ideas? The camera shutter works by simply attaching two wires together and the shutter fires.


This is quite new to me so any help or ideas would be greatly appreciated.

 

[Arouse1973]

Hello
Is the phone output on max?
Adam

 

[KTW]

It should be noted that this circuit will not work on many devices. Triggertrap actually had to release another design since the volume on many smartphones will not trigger the camera with the design in this article.

I suppose you read this?
Did you get the revision?

 

[scotteyre]

Hello
Is the phone output on max?
Adam

Yes volume is max, tried it on two phones max volume

 

[scotteyre]

I suppose you read this?
Did you get the revision?

I did read that but I could not find any revision.

 

[Arouse1973]

Yes volume is max, tried it on two phones max volume

You maybe be better off using a comparator and rectify the audio using a Schottky diode. You will need a small capacitor after the diode, you could configure the comparator as a Schmitt trigger so there is a bit of a dead band so more defined switching can be achieved.
Adam

 

[scotteyre]

You maybe be better off using a comparator and rectify the audio using a Schottky diode. You will need a small capacitor after the diode, you could configure the comparator as a Schmitt trigger so there is a bit of a dead band so more defined switching can be achieved.
Adam

I will have to research this one. Completely new concept to me. Thanks

 

[KTW]

It's a problem with Android.
http://www.synthtopia.com/content/2...-to-demo-low-latency-android-music-solutions/