Instructables

adding remote button to halloween screamer device

Hello!

I am pretty new to all this. In fact, this is my first project. down to the dirty part.

I have a battery powered screamer toy. It has a light sensor with a toggle switch and a push button that both activate the speaker. 

I want to add an external button in place of the internal one located on the circuit board. 

I have added a length of wire to the board already.  One end to the contact push button on the board, and the other to the point that connected to the other end of the contact push button. I scraped the copper off between the point where the second wire connected to the contact push button so now the only way they connect is through the added wire and tactile button. 

My problem is this.... none of it works now. Not even the light sensor. 

Please help!

Madonk (author) 7 months ago
pictures!
IMAG0065.jpgIMAG0064.jpgIMAG0066.jpgIMAG0067_BURST002.jpg
Madonk (author) 7 months ago
So I went and bought 2 more, and tried again with smaller wire. It seems to me like everytime I open one up, it stops working. I don't know whats going on. The black blob on the board gets real hot and the batteries get hot whenever I put them in. It looks like this is a loss. I give. It won lol. I can't spend $20 on these things to try and make one work. It was a good idea, it just seems like an arduino board would work better with a speaker and a program that plays a sound file when the button is pressed. I will look tomorrow for a board and parts, I remember seeing one on sale at radio shack. Thanks for all your help!
mpilchfamily7 months ago
Looks like your solder joint on top of the 2 contacts of the original button is shorting the button. So the devices runs through it's program once and still sees the button being held down so won't do anything else. You need to get each wire carefully soldered to the contacts so nothing is being shorted.
Madonk (author)  mpilchfamily7 months ago
It shouldn't have a reason to short. The right side of the original button circuits are not connected to anything. I scrapped the copper leading away so that I could replace it with my own length of wire and button.
It would help if you had clearer pictures and some of the board before you modded it.

What is that large solder blob in the middle on the first picture? Did the button your using come from the circuit board?

Judging by the size of the board, how big that solder blob is and how close it all is to the IC on the board there is a good chance you burned out the IC while soldering.
Madonk (author)  mpilchfamily7 months ago
Thats the best my camera would take. I didn't get any before hand because I didn't think I would have an issue. It's all pretty simple. The blob is where I was trying to make sure the new wire stayed. I had a tough go of it. I hope I didn't burn anything out. I have no idea what is under that black part. but where the blob is is where the rubber button pressed onto the board to trigger the speaker. But maybe you're right about it burning out, since the light sensor doesn't even work now.
The black parts are carbon traces that the rubber button shorts. There are 2 separate traces there and your solder blob is covering them both. The solder won't adhere to the carbon traces but if it's touching the trace it is making an electrical connection keeping the button shorted like i said earlier. Get rid of all the solder and try again. Try not to cover the other traces. In fact get rid of it all and test the toy again. If it still doesn't work then you had way too much heat on the board and probably damaged the IC. In which case you'll need to buy another one and start again.

Camera tip: Keep the camera at least 3 feet away unless you are using a macro lens. Putting the camera up close to the subject with the stock lens puts the image out of focus. The original picture size will be very large so by the time you crop out the stuff you don't want in the final image you will have a smaller image that will be clear and easy to upload.
Madonk (author)  mpilchfamily7 months ago
Yea, I need to buy a new one and try again. So question, When I get it, whats the first step Im going to need to do to solder my new lead on there? Do I need to carefully scrape away some kind of epoxy off of the button? I wouldn't think it would have any because that would stop the original button from being able to make contact.
The black under the button is a carbon trace. The carbon is conductive and used over the copper trace since it won't corrode. They could just leave it a bare copper trace but it will corrode and the button won't be able to short the traces like it should. While the carbon trace is conductive you won't be able to solder to it.

You will want to scrape away some of the green solder mask over the traces leading to the button and carefully solder your wire there. Then like i said below use hot glues to hold the wire in place so the strain isn't on the solder joint itself otherwise you'll rip the trace from the board. You want to be especially careful when soldering on the bare trace cause too much heat will not only damage the components but could cause the trace to lift from the PCB.
Toy and "import goods" electronics mods are always fun because you have to scrape away any finish coating to solder and you eventually melt off any useable solder trace. Check to see if the circuit is still good by turning it on by just shorting and probing with a piece of wire or paperclip, the part that you cut. If it still works, then try to change and solder one wire that you have on the contacts of your tactile switch to another leg. You really can't tell how they are wired up internally without a multimeter so a pair of legs on one side or the corresponding opposite side will be connected internally. Good luck.
Madonk (author)  caitlinsdad7 months ago
so what would be my best bet on how to do this? What are my steps? Do you think my wire is too big. and I do have a multimeter
You have the right idea but you need to use smaller wire and some better soldering skills. You may want to follow the 2 traces away from the button. Then scratch your way through the green solder mask to get to the bare copper and then solder your wires in. Use solder resin to help the solder adhere quicker and try not to saturate the board with heat. It should only take a second or 2 of the iron touching the wire and trace to get the solder in place. If you are worried about the wires getting pulled off the board, which is very likely on a small trace like that, then use hot glue to secure the wire to the board better.
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