No voltage on/off switch

levelhead · 2012-01-28 10:23

What two pins would I connect, to have a on/off switch with no voltage? What PBasic command would I excute? As in "High 13" (pg50 in manual) in the LED Test Circuit but without any voltage. I want to snap my camera and all I need to do is touch the two wires together as the remote button does when you push it. I have the Basic2 Stamp and education borad.

Duane Degn · 2012-01-28 10:33

I think you want the Stamp to control a relay. The relay would form the "no voltage" switch.

There are some relays the Stamp can drive directly, others need a transistor to provide enough current to activate the relay.

I believe there's a Nuts & Volts article about using relays with Basic Stamps. Parallax has copies of these in there download section. Let us know if you need help finding it.

Duane Degn · 2012-01-28 10:42

Here it is. The relay circuit is on the last page.

http://www.parallax.com/Portals/0/Downloads/docs/cols/nv/vol1/col/nv6.pdf

Kievlanin · 2012-01-28 11:03

levelhead wrote: »

What two pins would I connect, to have a on/off switch with no voltage? What PBasic command would I excute? As in "High 13" (pg50 in manual) in the LED Test
Circuit but without any voltage. I want to snap my camera and all I need to do is touch the two wires together as the remote button does when you push it. I have the Basic2 Stamp and education borad.

Well.
I am beginner, but I will try to help you. The crew will correct me were I am wrong:

The pictures are only TEST assembly for your switch.
Connect onel leg of the switch to VSS(ground) thru 220hm resistor.
The other leg go to NEG leg LED.
Positive leg of LED going to VDD(+5v)

The program to make a switch ON and OFF using software:
for BS1:
Positive leg LED to PIN1

Main:
PAUSE 2000
HIGH 1
PAUSE 2000
LOW 1
PAUSE 2000
GOTO Main

Was this helpfull?

Duane Degn · 2012-01-28 15:11

Kievlanin wrote: »

The pictures are only TEST assembly for your switch.
Connect onel leg of the switch to VSS(ground) thru 220hm resistor.
The other leg go to NEG leg LED.
Positive leg of LED going to VDD(+5v)

The program to make a switch ON and OFF using software:
for BS1:
Positive leg LED to PIN1

I don't think this is what levelhead was after since there is a voltage applied to the switch.

I think we need more information to be sure. I have a couple of cameras that could be triggered romotely with a push button. The push botton just closed a contact which triggered the camera. No outside power was needed; the switch just needed to be closed.

I assume this is the type of camera levelhead is using and levelhead just wants a way of controlling the switch from a Stamp. I still think a relay is the way to do this.

levelhead · 2012-02-06 20:46

I did this and at times it would work and I thought I had it but it worked at random. Thanks I'm a beginner too, I began 60 years ago.

levelhead · 2012-02-06 20:50

You are right Duane, I need a relay that connects two wires with no voltage applied to either wire.

Moskog · 2012-02-06 22:28

Relays are also discussed in the sticky thread Member Supported FAQ in this forum. Among many other things!

levelhead · 2012-02-20 08:06

Let me answer my own question. I purchased a chip(LTV-816) from Sparkfun whick did the trick. The chip has two circuits, one which you activate with the Pulsout command then the other circuit makes the connection. The camera does that half way down focus and exposure setting, and then does a click all the way down. So two LTV-816 chips were needed or just one LTV-826. See my video on YouTube for more info on how I built this circuit. Search (jgiralde and LTV_816).

BrianZ · 2012-02-21 16:26

I searched, but could not find your video. Can you provide a link?
HiViz sells a camera opto-switch kit that uses a similar 4-pin optocoupler chip (see http://www.hiviz.com/kits/cos.htm), which connects to their trigger circuits for input. The assembly instructions on that page shows how it's put together to connect to the camera's three wire cable release. They use the PS2501 shown on this page: http://www.hiviz.com/kits/comp_ic.htm . You may find some other useful info about camera connections on their pages. I use their multi-trigger circuit to set off my camera and flashes via radio transmitters connected directly to the outputs on their circuit, with receivers on the camera and flashes. Their trigger circuits use EC103D SCR's as switches, also shown at the top of that same page. I am adding to this a solenoid valve circuit using my Stamp to control the delivery of water drops.

levelhead · 2012-02-21 18:54

Sorry, I did just upload the video here is the link http://www.youtube.com/watch?v=7hV6YD73TDs . I will look over the links you sent. Thanks

BrianZ · 2012-02-22 04:43

Thanks for the link. Good job on the circuit. Just to clarify the identity of the cable release wires, did you say yellow was common, blue is shutter and black is focus? I would have thought the common would be connected to pin3 on both chips and the shutter and focus wires to pin4 on both chips, but it looks like you have the focus wire connected to the emitter at pin3 on the second chip. It would be interesting to see your program listing if you care to share it.

levelhead · 2012-02-22 06:46

Sure I will share the program with you. Send me an email address, here's mine jgiralde@aol.com . By the way I'm more of a programmer then a electircal engineer. If I need this wired different just let me know. Thanks

BrianZ · 2012-02-25 10:06

Thanks for sharing your program - it looks pretty straightforward, however, I just thought I'd let you know I saw a couple of inconsistencies...

First, the program comments don't agree with what the video says and shows. I'll explain... The video says the yellow and blue wires control the shutter, while the yellow and black control the auto focus, and those wires appear to be connected to the chips activated by BS output pins 10 & 11, respectively. However, contrary to this, the program listing shows pin 10 controlling auto focus and pin 11 controlling the shutter. I'm guessing you just misspoke in the video and the program listing is correct.

Second, I'm a little confused by how you have the camera wired to the chips. I would expect the camera's common/ground wire to be connected to the emitter pin 3 on both chips (at the lower right corner of each chip, assuming pins are numbered counterclockwise starting at the dot); yet on the upper chip it is connected to the collector pin 4 (where I think the camera's black shutter wire should be), so the wires appear to be reversed. Consequently, I'm not sure how it's working, and would be curious to see what would happen if you reverse the wires (the two on the right side of the upper chip at pins 3&4 controlled by Stamp pin 11 connected to pin 1 at the left side of the chip. I would expect polarity to matter in the case of the camera circuit, unless you were using a true "no voltage switch" (i.e., a regular manually operated swich equivalent to touching two wires together, as opposed to this optoisolator chip which requires voltage to be applied to operate), which brings me to another point...

Your reference to a "no voltage switch" seems inaccurate, since this application requires a voltage on both input and output sides for this electronic switch to work. The camera's shutter contacts, for example, are probably carrying a voltage of around 3V if you measure it. Sorry if this seems picky, or maybe I misunderstood. In any case, thanks for sharing this project - it's a great application of the stamp and a good example of how to safely connect a camera to an external circuit using an optoisolator, so there is no direct electronic connection between the two circuits. Also a clever use for controlling both the turntable and camera to automate the whole process. Thanks for sharing.

No voltage on/off switch

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