Introduction: DIY Spy Phone

Picture of DIY Spy Phone

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:

Picture of 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
... 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

Picture of 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

Picture of Building the Circuit

First about the TDA2822M chip:

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

Picture of 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

Picture of 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

Picture of 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:

How to make a tablet pc from an old laptop


Xbox Hackintosh casemod

Vote For Spy Contest and rate and comment!!!!!


DrunkProgrammer (author)2017-12-24

I can hear the capacitors discharging... How do I solve it?

conanslime (author)2017-10-09

Can I use old capacitors and other parts?

F1nnj1m3 (author)2016-10-18

that is cool

mkarvonen (author)2016-06-09

This idea is to make a powerful hearing aid to look like a phone...

spydude345 (author)2016-01-30

do they work

ErnestoS (author)2015-08-22

Can a smartphone be used instead and do this by software?

mkarvonen (author)ErnestoS2015-08-24

Sure. Why not? This is a example how to do it with basic electronic components. ie. how to make a amplifier.

Dr.Mhmd Rmdan (author)2013-12-25

can`t understand how to use it ? how is it work ??

mkarvonen (author)Dr.Mhmd Rmdan2014-01-12

Well. It amplifys the sounds around you so you can hear much better. For in this project the headline "Spy Phone" should say something.

maybolicious (author)2013-03-24

can you tells us which pins of the TDA2822 you used in the circuit ? the numbers of the pins. thank you :)

mkarvonen (author)maybolicious2013-03-25

The pin numbers can be seen in the datasheet. just google tda2822 datasheet.

maybolicious (author)mkarvonen2013-03-25

Will do :) thanks for the instructable, I plan to try it out in the not so distant future.

dermord (author)2012-10-13

nice one but what is it do?

mkarvonen (author)dermord2012-10-13

amplifying the sound around you so you can hear anything clearly and things that you wouldn't hear with normal hearing. "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." Read the damn thing and then ask questions.

dermord (author)mkarvonen2012-10-14

you didnt had to be rude....its all electronic ( I read all the post but its to much electronics hehehe) reaally really nice post! I`m thinkings seriusly to start learning electronic . If I do I`ll definitly try these one !

mkarvonen (author)dermord2012-10-15

The best way to start learning about electronics is to buy a toy electronics test board (the kind they sell at toy stores). Its the best and easyest way to start learning electronics because if you screw up you can easily start again (i always try my builds on the same kind of board before soldering to see if it works). so no soldering there. When you "master" that and think you can go to the next level. try soldering. just solder random components to a breadboard or something like that or try to build something to the board you have allready build on the toy test board.
You will need:
decent multimeter. just for measuring voltages etc. and learn that way the use of it. and has got hell lot of information in the future.
Soldering stuff. don't buy the cheapest you will find. its just pain in the ass. buy something you can change the temperature of the solderer(don't know if a real word.)
And open mind for anything
Remember. Start small and go big.

and remember also. when you get the idea of the components and the idea of electronics. its time to try programming the electronics. if you want i can send you a picture of 8-bit Attiny 2313 test and programming board (yea. you can do knight rider lights with that... so Nothing cool really ;) )

1codis (author)2012-05-07

The part you referred to as a "condenser" is actually called a capacitor.

Kiteman (author)1codis2012-06-16

"Condenser" is the old name for a capacitor.

mkarvonen (author)1codis2012-05-08

sorry. bad english

agis68 (author)2012-04-30

Its called Surface Mount Device SMD. Very neet instructable thow.

mkarvonen (author)agis682012-04-30

thanks. i will correct that when i get the chance :) i just happened to have some kind of brain fart and didn't remember anything... thanks for the reply!

edrandall (author)2012-04-29

My phone has a "voice recorder" mode. If I activate that, it will record everything just fine, no mods needed!

mkarvonen (author)edrandall2012-04-29

but not cool. every phone has got that mode. And you wont hear things in real time

mkarvonen (author)mkarvonen2012-04-29

and amplified volume

tundrawolf (author)2012-04-29

I love the fake skin from the battery screen! that's genius!

Scissorattack (author)2012-04-28

This seems like the best thing ever to make!!! Can you do it with any kind of phone? And where do I get the supplies? I have never made anything like this before, and I have no idea what a resistor or a condenser! Can u make a video please? Thnx for reading am comment!

Don't worry about me voting for you, cuz I just did. You are awesome to come up with this cuz i could have soooo much fun with this!!! THANK YOU!!!!!

mkarvonen (author)Scissorattack2012-04-28

yes. you can do it with any kind of phone. just make sure there is enough space inside the phone to put the circuit into. You can also try to put the circuit first into something bigger like inside a box or something than a phone.
Try to find the parts from here:
Try your local electronics store.(they will be happy to help you and to make sure you get the right parts.)

This is perfect project to do with your mom or dad or with friends

Also you will need soldering iron (any kind will do) and soldering tin

the parts are:
amplifier IC -TDA2822M x1
30Kohm resistor x1 ( the ohm is the basic resistanse of the resistor)
4.7ohm resistor x1
100 uF condenser x2 (the u is micro and the F is Farad)
10 uF condenser x1
0.1 uF condenser x1(the voltages about condensers does not matter much in this kind of project. try to keep them over 16 volts)
and some breadboard

Try wikipedia for learning about Amplifier IC, resistors and condenser. They are simply to use and simply to learn. and if you learn it your self you will remember it always!
I will not make a video about this project, but maybe in the future.
Happy building
If you have any questions just ask!
make sure you pressed the vote button in the upper right corner for Spy consest ;)

lnFAMOUS (author)2012-04-25

Great! Can I have more info on the specs of the condenser and transistors? Voltage and such? I'm new to this and don't want to risk messing up.

mkarvonen (author)lnFAMOUS2012-04-25

sure. keep the condensers over 16 volts and the resistors 1/4W and you will be fine. the circuit does not use big amps or voltages so there is no hazardous parts included. be careful with the amplifier to not to brake it (for short circuits and heating it too much with soldering iron). this is a good projeckt to start learning about electronics :)

lnFAMOUS (author)mkarvonen2012-04-26


ThatKnottyguy (author)2012-04-25

Love It 4 stars!
But alas, I am going to vote for one of my entries. Sorry!

mkarvonen (author)ThatKnottyguy2012-04-25

damn :D

mkarvonen (author)2012-04-25

Comment and rate!! also vote for spy contest when its available to vote

About This Instructable




Bio: I am 27 years old engineering student from Oulu in Finland. I make these projects as a hobby, and it would be fun to also ... More »
More by mkarvonen:PipBoy 3000 (working)DIY Piranha PlantPhoto(s) to 3D model
Add instructable to: