bent button

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So at work yesterday we got a button. All it is, is a big purple Yahoo button that someone got for free. You press the button and it plays Yahooooo really loud. Pretty boring. I figured I would open it up and show people how to smash their fingers on the resistors to change the pitch.

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So I unscrewed the thing and took a look. Pretty simple thing, of course the IC chip is a COB item underneath a blob of epoxy. This makes it really hard to figure out fun things. Someone then pointed out that there seemed to be a little 3 pin socket on the bottom of the thing. As I stared at the thing I saw that one of the pins was labeled Rec. Hmmm, I wondered if it would be possible to re-record the button to be even more obnoxious. I took a couple minutes and inspected the rest of the pins. I had two pins going to the switch to make the thing play. I had a Pl pin that if I jammed a wire between it and the positive power supply it would play. Alright Pl pin is a Play pin. It plays as long as you pull the pin high. There was the Rec pin, an IC pin a GND pin, two pins for the speaker and then a pin going to the resistor.

We sat for a while jamming wires on things and pressing our fingers on the resistor annoying everyone in the office. Then I finally tried connecting the Rec pin to the positive rail. Oops no more Yahooooo sound. I figured I blew something up. But wait I realized there was no more Yahoo but just a hissing. The I realized that the IC pin had a hidden letter and was really a Mic pin. Aha, I’m an idiot, so this turns out to be just a little 10 second recorder chip. All you need to do is pull the Rec pin high and input a mic or something else to the Mic pin and it will record.

We quickly cut up a mini jack cord, plugged it into my iPod and then touched the Rec pin to the power pin and it worked, kinda. It was way to quiet. I realized that I would need to bring the thing home and solder some proper wires to it in order to get good clear connections for recording. So I came home and started tweaking. First thing I did was reconnect the switch to the Play pin, this way when someone hit the button it would only play as long as the button was held down. Seemed like a good way to keep it less annoying if someone recorded something long. Second thing I did was to splice in a button between the Rec pin and the power supply. This way I didn’t have to hold some wire every time I wanted to record. Then I connected a mini jack connector to the Mic pin so it would be easier to record things. The final step was to take the Dremel and make some holes for the new input jack and button

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It came out pretty good. The only problem was the button didn’t hot glue to the case very well. So I ended up just keeping it outside the case until I get something better to attach it. The only thing left that would be cool to do would be to get a decent variable resistor so you can mess with the pitch while holding the button. Over all, a fun little project for the night.

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Posted on May 9, 2008, in Electronics, Reverse Engineering and tagged , . Bookmark the permalink. 7 Comments.

  1. I’m trying to replicate your hack, but before I pop the case, two quick questions:

    When you connect the REC pad to +, do you just touch it once and start recording or do you need to maintain the connection through the entire recording?

    When hooking up the mic, do you connect one end of the spliced line in to MIC and the other to – ?

    Thanks.

  2. You will need to maintain the connection of rec to + the whole time while recording. What I ended up doing was soldering a wire from the rec pin to one side of a button and then the other side of the button to the + terminal on the battery pack.

    You are correct about the MIC as well. The one side of the mic will connect to the pin and the other side will go to GND. On the bottom of my button there is actually a small 3 pin connector for all this. One pin for GND, one for MIC and one for REC but for my purposes it seemed easier to do everything inside the button.

    I’ve also hooked up a 100K linear potentiometer and mounted in the middle of the button and it’s great fun. Whatever resistance it’s at when recording becomes normal playback speed and then fiddling with it during playback speeds up or slowdowns the speech. I only wish there was more than 10 seconds of record time.

  3. Perfect. I’ve got a new message recorded. 🙂 Thanks for your help.

  4. Hah, this looks fun. I’ll have to find my Staples “That was easy” button and see if it works the same way.

  5. Hi, I performed this modification but am having a little trouble. The momentary play switch works fine and it will record what I have connected to the jack. The problem is that the volume is way too low. The Yahoo sound was a lot louder. Any help would be greatly appreciated.
    Thanks, J. Muller

    • I had this problem at first too. I found the key is just to make sure your audio source is loud enough. For some things I actually used Audacity to increase the gain on the clip and then play it from the computer. I have the button at work now and I seem to get good results just from the line out of our dell machines though. Unfortunately since I didn’t add a volume knob it’s just a lot of trial and error.

  6. Hi, Thanks for the response. I tried Audacity and was able to make it louder but no matter what I do, its distorted to the point that you can barely make out what the song is. I must have screwed something up that I’m not aware of.

    JM

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