[piesforyou]

still not clear.... I have an Android phone; I download the app and then what? Is there anything else I need?

Well you will need to build or buy the IR cable as well. It uses the audio port on your phone to control the IR LEDs which in turn send the signal to the IR sensor on your camera.

[Skog]

This is awsome! Im going to try it once I get the time.

[surfi83]

Hy,

i want to try this with a Canon. How can i find out the code which i have to send?
Or perhaps somebody still have it?

I hope u can help me.

[piesforyou]

I'm not sure what the code is for canon, some quick googling didn't turn it up.

But my suggestion would be that for canon someone's more than likely done it before, so you may be able to find their how-to, and also there may well be a better option - does your cam have a wired trigger port? In which case you can pick up a wired intervalometer for very cheap off ebay.

[Pentaxor]

Edit: There is now a dedicated Android App for controlling your Pentax camera using this method. Get it here:

LINK (New version 1.1 with vastly improved range)

It is not on the Market Place because it was developed using Android AppInventor which does not (currently) allow you to upload apps to the marketplace.

This BETA! Please report bugs :-)


Thismorning I stumbled upon this Instructable detailing how to make an IR transmitter using an audio jack lead, which would then transmit any IR code using a custom .wav file. This is one of those situations where in a cartoon a lightbulb would have appeared above my head - idea!

So this is a very quick guide as to how to utilize the IR lead in the above instructable (and kudos to alberto_canvas for a very informative guide as to how to make the lead) in order to use any MP3 player/phone or laptop (although I would highly recommend PK_Tether in that instance), basically ANYTHING that can play an audio file, as an intervalometer or remote timer.

Here are some shots from my build.

I started with a headphone extension lead, from Poundland (luckily I thought the one Maplin sold for £7.99 was a ripoff) and the two IR LEDs are from Maplin, code YH70M, just over a quid each.




Testing. Believe me, when the shutter went off this was a real EUREKA! moment for me. You have to wire them up so that the positive leg from one LED is attached to the negative leg of the other LED. This is NOT a parallel circuit - they are two opposing diodes. This becomes clear later. Also, my lead has a red, white and yellow wire. The yellow is ground, and is not connected to anything.


I decided to file down one edge of each LED so that they fitted next to each other nicely (you have to make sure to file the correct side on each one else the leads don't go well together)


See I started filing the wrong side on one of them.




I used thin shrink tubing on one lead and then larger shrink tubing to cover both the leads, then wrapped the whole lot in insulation tape.


Finished. Very simple. I guess it took about 2 hours to make but that included the time it took me to figure out how to make the .wav file work.


So that's the lead. The next step is the .wav file. I found the correct code from this thread. It looks like this.



So here's the important bit. To be honest i'm not sure that what I'm about to say is technically correct but, well it works so there you go. The IR code signal is 38kHz but the .wav file we will create cannot go that high. So what we do is use pulses of 19kHz, and because we have two LEDs wired opposing each other, one LED will 'light' up during the positive part of the wave and the other will light up during the negative part of the wave, so that for each wavelength we actually have two pulses - so a 19kHz wave gives us 38kHz pulses. Follow me? To make sure this works, only one channel (I've made it the left channel) can transmit the signal because if both channels do then they cancel each other out. Or you could invert the signal on the right channel (possibly leading to a stronger IR pulse - need to experiment with that).

The signals are created simply using the "Generate, Tone" function in Audacity. I specified a square signal and 19000 Hz, for 13 milliseconds for the first long pulse and then 1 millisecond for the subsequent pulses.

Here's a screenshot of the .wav file I created, I used Audacity which is free.

LINK

Once it is saved as a .wav, use windows media player or something to check it works. In case you hadn't guessed, the lead you made just plugs into the headphone jack of your computer/MP3 player/whatever. It's funny though - this didn't work with VLC. But windows media player did work. Meh. It also worked when I converted the file into an MP3, but possibly less reliably? Not sure. I would stick with wavs unless your device can't play them.

To make this into a useful timer, you need to create a track with the signal at the beginning, followed by X amount of silence, and then simply play the track on repeat. However I have found it hard to gauge how much time to leave - for example when you set the shutter speed to 30 seconds the time between shots is actually a bit longer than this. For this reason I prefer to use bulb mode, so the .wav is laid out like this:

SIGNAL - 30s silence - SIGNAL - 2 seconds silence

with this on repeat, the camera will continuously take 30s shots until the memory card is full/batteries run out. Whatever, experiment, see what you like. Watch out for DFS though, but then you could even account for that by putting in the appropriate amount of silence for DFS.

Anyway the point is this is a really really simple way to make your k-x into a time-lapse or astrophotography beast! You could even set up a playlist to give you, say, 100 exposures at 30 seconds, 10 exposures at 5 seconds, or whatever. I'll be making some sort of mount to attach the lead to the camera close to the IR port, possibly even just an elastic band or something.

Finally here's a zip of the audacity project and the raw .wav file (Now with improved range by putting the inverted signal on the opposite channel)





Hope you enjoy.

EDIT:

This is why the mp3 does not work quite so well:



I didn't imagine the mp3 would be quite so screwed up! I would definitely recommend some sort of lossless compression, for example ogg vorbis which looks a LOT better:



Also, as lavascript points out, this is useful for any pentax camera not just the k-x. However it is particularly useful for the k-x as it has no timelapse functionality.

Edit #2:
Android app is in progress. It is functional as a basic intervalometer at the moment, needs a bit of spit and polish but I should be able to 'release' it soon.

MP3 (sound and signal quality) was never better from the start. it became so popular only due to it's compression capability, not quality. people usually needs more storage for their music. since storage devices have become significantly cheaper and affordable nowadays, MP4; which is a better format; finally broke out of it's shell. honestly, MP4 is long overdue. it came out about a decade ago but never really became that popular not until recently. although it is still a lossy compression format, it is still better than MP3. the only problem with the Mp4 is that it is not yet universally compatible with all devices, unlike the mp3. but it's a start.

[Ira]

This is way beyond my brain's capacity, but I really need a remote on my K-x for B mode.

[pacerr]

But I'm old enough to remember why we still say we "dial" the phone.

I can build cables all day, an' I even recognized a mini-phone jack at a Holiday Inn Express once, but my programing skills 're still flashin' 12:00 and my Android's out of service for an oil leak in its secondary hyper-frog-thingy.

So would one of you wizards please post a coupl'a useful .WAV-coded MP3 files for Ira and I to download and play with in the back room between naps? Just think of it as codes-on-wheels for ol' geezers.

H2

[piesforyou]

This is way beyond my brain's capacity, but I really need a remote on my K-x for B mode.

It would be quite easy to make a track for B mode. It would look like this

CODE - silence for exposure - CODE - silence for pause of camera getting ready to take the next exposure

Then just get your MP3 player to repeat that for however many pictures you want to take. If your exposure is long enough to invoke dark frame subtraction then you'll want the second silence to include enough time for DFS to take place.

But I'm old enough to remember why we still say we "dial" the phone.

I can build cables all day, an' I even recognized a mini-phone jack at a Holiday Inn Express once, but my programing skills 're still flashin' 12:00 and my Android's out of service for an oil leak in its secondary hyper-frog-thingy.

So would one of you wizards please post a coupl'a useful .WAV-coded MP3 files for Ira and I to download and play with in the back room between naps? Just think of it as codes-on-wheels for ol' geezers.

H2

You know, thinking about it, if you use a shutter speed instead of bulb mode, you can just use the .wav I've posted and simply get your music player to repeat it endlessly. The camera doesn't respond to the IR whilst exposure is taking place, right? And it will fire again as soon as it's ready.

If you want some bulb mode timing tracks, let me know what exposure time you want and I'll knock some up for you.

[Billium28]

Awesome, let me know how if it works!!

OK So I ordered the LED's, IR that is, and a simple cable like yours. I soldered the red and white wire to the LED's. I made sure to solder one negative with the other positive. I soldered the red wire to one combined terminal from the led or the other, from what I can tell this wouldn't matter. Anyway I plugged the other end into my droid, loaded up your software and nothing happened. I own a k-x and I set it to remote and I held the led's all around the ir receiver on the cam but I didnt get anything. I will try tomorrow by redoing it all from scratch but I think I have it right.

[Voytech]

Before you take it all apart, check the volume on the droid. Should be all the way up. That's the only thing that comes to mind.

[piesforyou]

OK So I ordered the LED's, IR that is, and a simple cable like yours. I soldered the red and white wire to the LED's. I made sure to solder one negative with the other positive. I soldered the red wire to one combined terminal from the led or the other, from what I can tell this wouldn't matter. Anyway I plugged the other end into my droid, loaded up your software and nothing happened. I own a k-x and I set it to remote and I held the led's all around the ir receiver on the cam but I didnt get anything. I will try tomorrow by redoing it all from scratch but I think I have it right.

Yeah as voytech says, make sure your Droid volume is up. Also, you could try plugging in a pair of stereo speakers and when you press shutter release you should hear a short beepy sound, that's the code. If you can hear that, you know the android side of things is working.

You can test the LEDs by using it with your laptop and the .wav file I supplied.

From your description, I'm not too sure what you've done with the red wire. Is it soldered to one positive and one negative leg of the LEDs?

[Billium28]

Yeah as voytech says, make sure your Droid volume is up. Also, you could try plugging in a pair of stereo speakers and when you press shutter release you should hear a short beepy sound, that's the code. If you can hear that, you know the android side of things is working.

You can test the LEDs by using it with your laptop and the .wav file I supplied.

From your description, I'm not too sure what you've done with the red wire. Is it soldered to one positive and one negative leg of the LEDs?

Ya it was hard to describe in the wording there. Let me just make sure if this is correct:

Take the one short terminal on one LED and the long one on the other connect them (solder them) right? Also does it matter which of the two wires from the headset wire connect to either of the new LED terminals?

And the final question I have does the LEDs have to pointed in any certain direction? I have fiddled with it in every direction but I noticed you taped the sides of yours, though I think you did that to keep them together.

I am going to plug in the laptop and try that now. Thanks for your support.

[kxr4trids]

MP3 (sound and signal quality) was never better from the start. it became so popular only due to it's compression capability, not quality.

I suspect the problem with mp3 is that the compression is optimized for human listening and this signal does not fall into that category. Not unlike a jpg throwing away detail in sky or shadows.

[Billium28]

Ok, I got it working fine. A couple of things that may have contributed it. For one thing I made sure the volume was all the way up but in that app you made it only turned up the ringer. I went in winamp and turned it up there and found that it was low. With the media volume up, I believe it worked.

Its great, I cant wait to use it! Thanks!

[Voytech]

Great. Good to hear about your success.

I have all the parts ready, just waiting for some time to put this together.