The Staples "Easy" button is already a classic desktop item, but it'd be much more fun if it said whatever you want it to. I know that some people have already done hacks like this, but this is less expensive than many of them. Also, Staples recently changed the circuit board of their button, making it harder to hack. This Instructable will show you how to hack the most recent version of this knick-knack.
Here's a quick demonstration (it's a little bit quiet, I'm not very good at talking loudly):
For this project, you'll need a free weekend to work and moderate electronics/soldering experience.
Convinced yet? Good!
First, get some materials.
Step 1: Materials
1x Easy button (http://www.staples.com/Staples-Easy-Button/product_606396?cid=PS:GooglePLAs:606396&srccode=cii_17588969&cpncode=34-101107153-2)
1x ISD1820 Recording Module (eBay: I got mine from the USA for a few dollars extra because I wanted it more quickly, but you can save a bit of money by getting them from China)
2x small momentary pushbutton switches (one can be of any type, one should look like this (6mm x 6mm x 1mm button): http://www.ebay.com/itm/Quality-Momentary-Tactile-Push-Button-Switch-SPST-Miniature-Mini-Micro-Small-PCB-/180732232689) - it looks like http://arduinotutorial.altervista.org/wp-content/uploads/2011/03/MomentaryPushButton-01a-L.jpg
For the other switch, I used this: http://www.radioshack.com/product/index.jsp?productId=2062546
A bit of hookup wire (I used 22 gauge)
Heat shrink (optional, but recommended)
A soldering iron
A Dremel or other small rotary cutter
A hot glue gun with glue sticks
A phillips screwdriver
A drill (optional)
Step 2: Take the Button Apart
Finally, remove the two steel weights. You can discard these weights along with the piece of sheet metal; they aren't necessary in the final build and just take up valuable space.
After that, desolder the speaker from the circuit board and the circuit board from the battery compartment.
Step 3: Prepare the Parts
Also, test the recording module to make sure it's working. Attach the wires of the speaker to the green terminal and attach 3 volts to the GND and VCC pins on the right of the board (make sure to check the battery's polarity when you attach it). Then, flip both of the slide switches at the top of the board to the left. Press and hold the REC button to record something, and press PLAYE to play it back once. The PLAYL button only plays the message while the button is being pressed, so that one won't be used. If everything works, move on. If not, check all of your connections to see if there's a problem. It should work at that point.
After that, desolder the microphone from the board. The microphone is the small cylindrical component with the silver sides and black top. There should be a label on the board next to it that says "MIC." Attach wires and heat shrink to each lead of the microphone, and remember which lead went where in the circuit board (I'm not sure if it matters, but remember just in case). Then, solder it back into the board in the same place. Now it'll just have longer leads and be easier to access.
Then, using a Dremel tool, cut a hole in middle red plastic piece of the button just large enough to fit the recording module (again, see the picture for guidance).
Solder wires onto both leads of each momentary switch and protect with heat shrink to extend the connections. On the 6mm x 6mm x 1mm button, each lead only needs to be about 1.5 inches. On the other button, they should be between 3 and 4 inches.
Next, get the button head (the red part that says "easy" on the outside). On the inside are cross-shaped pieces of plastic. At the intersection of the cross, using a Dremel, shave off a couple millimeters over an area wide enough to accommodate the 6mm x 6mm x 1mm pushbutton switch. I've also included a picture of this to help. The reason for this is to make sure there's enough space for the new switch you'll be installing to move freely.
Finally, remove the white rubber button from the button's original circuit board and wrap a piece of electrical tape around the board where it used to be.
After this comes assembly!
Step 4: Begin Assembly
The switch goes between the four alignment holes (the holes that meet with the four prongs on the bottom of the Easy button head) in the circuit board. It replaces the white rubber button that was there before. Try to flatten it as much as possible before you glue it down (make sure the wire leads of the switch don't make it stand up above the board). When you've adjusted the switch's wires so that the switch lies flat on the board, glue it in place with hot glue.
The next step in the first stage of assembly is to mount the recording module inside the piece of plastic that was cut in the previous step. Make sure that none of the module is sticking up from the red plastic bed, as this will cause problems in assembly later on. Fasten it in place with hot glue once you've finalized its position.
After that, find the pushbutton switch you soldered longer leads onto earlier and solder one of the leads onto the wire we attached to the recording module. Then, also solder one end of the 6mm x 6mm x 1mm onto that same wire. I've included a picture to show what it should look like.
Once that's finished, you can move on to the next stage of assembly.
Step 5: Assemble the Inside of the Button
Now comes the time to connect everything electrically. I've included a simple diagram and photos to outline the connections, also. First, connect the other lead of the 6mm x 6mm x 1mm button to the header pin on the right side of the recording module labeled "PLAYE." This is a tricky solder, and I'd use flux to make it easier (I didn't have any at the time, so it's still possible to do it without). Then, solder the other lead of the other pushbutton switch to the header of the module labeled "REC." This will also be a bit hard to solder. Finally, solder the two wires coming from the button's battery compartment to the "GND" and "VCC" headers (make sure to observe polarity!).
Once you've connected everything, test the electronics. Put the AAA batteries into their compartment and record something by holding the small pushbutton switch you just attached. Then, press the 6mm x 6mm x 1mm switch. If it plays your message, it works. If not, double check all your connections. Only proceed once everything is in working order.
If everything works, screw the green board that came with the button back into its place (on top of the blue recording module board). Then, put the speaker (still attached to the recording module board) back into its slot at the bottom of the button's housing. Glue the top assembly (with the circuit boards) onto the bottom one (with the speaker and batteries). Make sure it's oriented the correct way!
Step 6: Drilling Holes
Placement of these holes is very important. There must be empty space behind them to fit the switch and microphone. The best way to decide where to drill them is to find an empty space, put the silver part of the button's housing back onto the bottom of the housing, and mark the part of the silver plastic where it lines up with your empty space. I've included pictures showing where I drilled the holes (IMPORTANT: the silver plastic of the housing only fits with the bottom in a certain way, so make sure you've accounted for this when you're marking where you want to drill).
Once you've drilled, secure the microphone into its hole with some hot glue. Wait before you glue the switch into its hole.
Step 7: Final Assembly and Recap
Then, slide the ring and head into position over the button's interior. Make sure the screw holes in the ring line up with the screw holes in the bottom of the housing (they make a trapezoidal shape, so there's only one possible orientation where they'll all fit together). Then, slowly and evenly slide the ring onto the base until you can begin re-securing it with the button's original screws.
If you're having trouble getting the ring to slide far enough towards the bottom, one thing you can do is to cut grooves for some of the wires with your Dremel (like the wires that go to the small pushbutton and microphone). This will kind of inlay the wires, preventing them from protruding.
Once you've done that, tighten the four screws in the bottom (if it's still having trouble fitting over the rest of the button, not too tight!). Then, press the Easy button a few times. If you can hear the switch being pressed freely and not being held down, you're done! Just reattach the button's rubber feet, reinstall the batteries, and test it!
Testing and Recap:
All you have to do to use the button is hold down the small pushbutton to record, then press the Easy button to play it as much as you want! When recording, make sure to speak loudly and clearly directly into the microphone. Unfortunately, there'll sometimes be a bit of static if there's too much background noise. The more directly you speak into the microphone, however, the less of this there will be.
Now, I know this type of hack has already been done before, but I don't think one has been done with parts this inexpensive and components such as the ISD1820. At least, I've never seen one. If you've done this before or have any suggestions, feel free to leave them in the comments or implement them yourself! I know my work can be improved upon, and I always want feedback. Thanks for looking, and good luck!