This project is good for learning the basic idea about electronics and its fun to do. The build is very easy to make and safe to use (no hazardous parts).

The idea about spy phone is that it looks like an ordinary phone. I made this instructable just for the spy contest (and have thousand ideas to come) . challenge in this project is to make everything small as possible. You can use in this project any phone you have (including mp3 players and everything that is small and mobile). The thing about the phone is that is actually a super sensitive hearing device that you can use everywhere and no one will ever know what you hear. Now if you build this, i'm not responsible for any action you use this device for.

Step 1: This Is What You Will Need:

obviously you will need an old phone(or new if it's not about cash) or a dummy phone. you will probably find an old phone from your own home/ ask your friends that do they have any or buy from Ebay, second hand store. You can find also a dummy phones from internet, google is your friend.

The components that you will need are:
The amplifier IC -TDA2822M
Few resistors- one about 30Kohms for the microphone and 4.7 ohms
four condenser- one 0.1 uF, one 10 uF and two 100 uF.
Battery (i used a phone battery because its small and easy to recharge on another phone. it has 3.7 volts and 600mAh so it will last. keep in mind that the amplifier needs only 1.8 volts to work and maxes out on 15 volts)
small switch
3.5mm audio jack
microphone (smallest that you can get)
and something to solder the parts to
and some wire
and tape
and
and
... i think that's all. use your imagination if needed

Tools that you will need:
sharp knife to cut the plastic if needed
Small screwdriver
Soldering iron

Ps. If you have the chance. do this project to surface-mount (i'm not sure about the right word) and use the smallest parts possible.

Step 2: Clear the Phone From the Old Parts

Just screw all the screws from the phone and "empty" it. meaning that take everything out from it. leave the plastic parts only (keep in mind that the phone has a small microphone that you can use. i didn't :D)
also if you have an battery in the phone that is in some sort of case ( like in this phone) empty it too. But be careful not to puncture the battery inside the case.
After you have removed all the parts from the phone it should look like in the last picture.
(by the way. Thank you instructables for the leatherman juice s2!!. It is very handy tool to use :))))

Step 3: Building the Circuit

First about the TDA2822M chip:

DESCRIPTION
The TDA2822M is a monolithic integrated circuit in
8 lead Minidip package. It is intended for use as
dual audio power amplifier in portable cassette
players and radios.
very handy chip in use and low cost

In this project its only one channel (mono) because i didn't have the room to add few capasitators more. the audio jack makes it for the both channels but from the chip its only on one channel (you can make stereo by using both channels and using two microphones or bridge the channels)

Now when you have the circuit board ready. start soldering the parts on to it by copying the layout from picture 3 (if you have something to say about the layout please do say it. i'm not perfect about it and it might have lots of work to do about it, but for me it works just fine).
In the layout at the speaker part you put the audio jack.

Remember to fit the circuit to the phone after every added component that it fits in the phone.

Step 4: Battery Installation

I was about to use V23GA battery instead of the phone battery but could not find any. But the phone battery works just fine.
So i mounted the Battery inside the screen lid with the microphone (microphone wires not showing in the picture 2, just trying to see that the battery fits in the lid). If you do the same thing put the text side up so it seems that there is light on the display
I put the microphone to the same place where the phones speaker used to be.

Step 5: Final Touches

So Just push everything inside the phone and hope it fits there. also if you like you can put a button aside the phone so if you press it, its on and if you don't its off. also i put the audio out jack to other side the phone. just drill a small hole where you want it.

Step 6: The_Spy_Phone

And by now you have a working spy phone. now go and secretly listen conversations you tease your neighbor or do what ever you like. (i'm not responssible of any action made with this).
Have Fun! :)
Any questions will be answered!.
And most of all Greetingsfrom Finland!
Stay tuned. Huge project comming in a few months. i have been building it for about half a year. It will include computer, drawing, huge touch screen and also angry birds.
small projects like this one will come soon too.

If interested Check these out too: