Alarm Phone Dialer – uses MT8880 and PIC 16F84A

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Just hook this Alarm Phone Dialer up to something you would like to monitor, for example, a high water alarm, low temperature alarm, back window, garage door, etc. When the system is activated it will call a number of programmed numbers to let you know the alarm has been activated. This would be great to get alerts of alarm conditions from your home when you are at work. The microcontroller code is provided on the site. The circuit uses a MT8880 DTMF dialer chip and a PIC 16F84A microcontroller. If you don’t feel up to the challenge of building your own dialer you can always look to the professionals to monitor anything you like with a modern security system.

“After putting together this little device, you must enter programming-mode to learn some phone numbers which this module will call after detecting an input on it’s sensor pin. After programming just supply power to the device. After pressing the button “Pokreni dojavu alarma” it will start to dial (tone or pulse, depending on the jumper setup). When the phone call is successfully established, the called party should press pound key “#” to stop the device from calling another number or again. You should put a sensor instead of button “Pokreni dojavu alarma”. Programming the numbers 1. press the “program” button 2. pick up the phone that is connected to the same phone-line as this device 3. punch-in first number and then “*” key 4. punch-in then next number and then “*” key 5. punch-in the rest of numbers, if more, and finalise with “*#” (example: 061123123*061456456*#) Please note: The device will learn 64 characters/digits including * and # keys.”
Thanks Muris.

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118 Comments


  1. A “real” burglar would cut the phone line (and prolly the power too) before entering the house.. Pretty weak.. :p


  2. Hi Dave,

    It would be no better that a modern alarm system, most alarm system still use dialers that use conventional phone lines to call out. It is usually quite expensive to get a cell backup installed. Power could easily be taken off a battery backed up source.


  3. Doesn’t seem like the picture matches the PCB.


  4. Actually Alan, in the United States, a lot of companies will install cellular modules at your request….you can just tell them that you have no home phone service.

    Steve, The two look dead on to me.

    This looks like it might also be kind of cool to add to a radio repeater to give it autopatch capability!


  5. Dave,

    If you’d read the documentation you’d of seen that he was suggesting that this was for home automation and monitoring. The examples he gave were for high water in the basement and low temperature type alarms, not burglar alarms. I wouldn’t call it “weak”.

    As for dialers that use Cell, I JUST got a bid from an alarm company who would do a Cell based portable alarm system for about $1500 plus $40/mo to monitor it so that while my partner is flipping houses we can keep security on them. That was a whole lot cheaper then I was going to be able to build one for so… yeah, those are available too.





  10. Wow, this would really be quite usefull for a summer house or a property that you dont spend alot of time at.


  11. I’m confused by this site and this post. I want 1 of these alarms to monitor temperature
    on a cooler and freezer. How can I buy one?


  12. Were can I purchase one of these!! I am in dire need of one ASAP!!!!


  13. If you want one you have to build it. 🙂 Click on the link in the article for full construction details.


  14. i need the asm code. i am reading the MT8880’s datasheet for settting. i don’t understand why the pin CS(chip select) is connect to ground.???
    i’m probe the circuit step by step and i need generate dtmf tones but i can do it 🙁
    excuse for my bad english


  15. CS is grounded because that’s the only chip on the 8-bit bus! It’s something like: “enable MT8880 allways”.


  16. necesito el asm porque si no no puedo probarlo y grabar el pic muchas gracias


  17. Hello,

    It’s really cool to me, but it would be great if you can have voice messages included, also busy tone detection & redial.

    Thanks,
    Hasen


  18. It has redial, it is dialing over and over until you answer and press the # pound key.


  19. We have wireles radio with motion sensor to communicate with dialer. We want to add cheaper dialer and fasten sensor with radio by magnetic strip on tractors, tool boxes, back-hoe, etc. When it moves we want to make 3 phone calls. Needs to be cheap so construction firms can put one on all expensive equipment.

    Radio has range 1000′ and be extended by repeater. Wireless FCC approved this year and managed bysoftwarel


  20. Hi Allan, Farm Alarm looks like an interesting product. There are a few dead links on your page though. FAQ for example.


  21. Hi Allan, Can you please give a full component list? I am not able to get the value of the
    component used very next to the phone jack (blue colour). Pl. help me with this. Do I
    have to connect a Switch above the LED? Please explain the connections on the same…. The PCB
    has got two transistors and the schematic has only one… that is why this confusion. Explain
    on the connection for “Program mode” and “Trigger mode”.. Thanks. Shiva


  22. What’s the price, and how can i order this kit (Alarm Phone Dialer – uses MT8880 and PIC 16F84A).


  23. how can i buy this alarm


  24. Hi Shiva,

    Blue color capacitor you can find in any normal phone, it will be used same way in this circuit.

    i think its not a transistor near the phone jack its a part of the transformer.


  25. Hi shiva,

    sorry black color is not a part of the transformer


  26. A professional burglar would not only cut the land line he/she also would employ a cellphone detector and jammer which are very simple devices.
    Though this or a cell based dialer might catch some random crack head breaking into your house looking for something to hock for quick cash of course they could likely be gone by the time security and police arrive.
    Lastly do not have an alarm directly dial 911 as you can get in trouble for prank calling 911 if you get several false alarms.


  27. Another use for this circuit might be to have it monitor something like a battery bank on a solar/wind setup and if the volatge drops too low or goes to high it calls your cell phone.
    Or mod it to run off 12v and communicate with a cellphone or phone module and use it as a silent car alarm that calls you if your car is broken into.


  28. Hi,

    I would really appreciate if it is possible to have C source code for the pic84

    Thanks,
    Naeem


  29. Hi Naeem,

    Click on the project link to take you to the project site with the downloads.


  30. It’s taken me a while but I have finally found a
    place to purchase the MT8880-dip chips. They are
    discontinued by the man. and I can get about 50
    of them. If you want one drop me a line or email
    address.


  31. Some of you people really don’t listen, do you? Or maybe you can’t read. Alan says this is for monitoring things around the house (like high water levels, door open ,etc). He never said it was a burgler alarm. For its intended purpose, it’s a great little device. If you want a burgler alarm, pay some alarm company the big bucks for one. But please remember, the “professional” systems are flakey, too. My neighbor has a very expensive professionally monitored system, and it false alarms at least twice a year.


  32. where are you list of components?


  34. i opened the website you gave but i can’t find any list of components. I need the specific components from the minor to the major one. Thanks so much


  35. I think they are in the download file. If not email the creator from his page and I am sure he will help you out. 🙂


  36. i am very interested in this project and it simply represent a part of my graduation project so i will be glade if you sent me the source file of the code knowing that i disassembled it but it was not clear to understand
    so please send it to me to my email(zaidaliali@yahoo.com)and i will be thankful ther is no time for my proposal


  37. Hi zaidali,

    Great grad project. You will have to contact the creator directly though, click on the link in the article.


  38. this website offers the advantege of disassmbling the hex file of this project
    it was helpful for me i hope it will be useful for you
    thanks alot for your help


  39. I’ve been hoping i could get more sources and tge components of this dialer brcause this is my final project. tnx


  40. thanx zaidali for the disassembler


  41. hi, my friends and i are planning to make a phone alarm for our project and we’d appreciate it if you could send us the source code. my e-mail id is GKSville@gmail.com. i’d be so so so very grateful if you could send it to me


  42. please any body could tell where can i buy the mt8880
    thanks


  43. I have some of the chips if you want one
    you can email me at bcideinc AT yahoo DOT com


  44. Please Alan said that is a link to the creator but I cant find it
    please I need a material list and the cod for it
    please anybody email me
    importeusa@hotmail.com
    thanks


  46. please alan could you help me ?
    the board doesn’t macht to the esquematic so I can’t came out with an idea about the material list
    I can’t figure out What kind of capacitors are those all of then
    and it show 1 bc547 but the board show some smd and there is nothing in the squematic about these smd transistors
    and the ZD 1v what is thas ?is a diode zener ?
    please
    thanks
    importeusa@hotmail.com


  47. I need better spec for this transformer what is it ?
    thanks


  48. It is a transformer from an old PC telephone modem. 600ohm resistance, 1:1.


  49. hi every one
    doest anybody know what do i do to the pic pin #4
    becouse the squematic says to vcc but the board show a resistor on it but no where say the resistor valuer


  50. what’s the zd 1v component? there is no 1V zener diode available, but the configuration in the circuit is similar to a zener. all the same, i have no idea wat it is. could someone help me?


  51. >what’s the zd 1v component? there is no 1V
    >zener diode available,

    I think it is supposed to be 5.1v zener diode judging
    from other circuits I’ve found.

    >hi every one doest anybody know what do i do to the
    >pic pin #4

    Look for other pic chip wiring and use what ever
    they use. I believe but not positive from my old days
    working with the pic chip it was 5v connect no resistor.


  52. no puedo bajar nada alguien me puede ayudar


  53. Does anyone know how can I program the code into the chip?


  54. Hoala!. Gracias por contestarme, podrias mandarme archivo alarma gsm, no lo puedo bajar y lo que pueda en español, muchas gracias.
    la pagina esta buenisima.


  55. no puedo bajar alarma gsm, alguien me lo puede mandar porfavor, gracias.saludos


  56. Trax,
    Where can i download the asm file and the components lists for GSM Call Alarm?
    Or may u pls send me an email…Or post here also can…
    Thanks a lot..


  58. i want a proj related to microcontroller based appliance controller using DTMF


  60. Thank you!I like to try it.


  61. hi
    how i can control mt8880 pillers with plc micro to send dtmf signals?
    thanks


  62. @ aribi: maybe you could try using the UM91215A DTMF/pulse dialer. i found that one way easier to use than the MT8880


  63. Good afternoon. I am looking for a wireless, off the shelf, (GSM Telephone) interface for the typical house alarm system, so the alarm system will originate an outgoing call when the alarm system is triggered. This interface needs to function like your typical copper wire house telephone. My goal here is two fold first being able to get rid of the expensive house phone and second to have a system that the intruder/burglar can not cripple by just cutting the telephone line or the house power.


  64. Depression Depression Depression aaaaaaaa
    HEEEEELP 🙁 🙁 🙁
    I hate winter! I want summer!


  67. Pl. let me know how the phone nos. are stored in the micro controller.
    is it in the ram or eeprom area? if it is in the ram area then in case of power
    failure the stored nos may get lost.pl. clarify & mail me the solutions.

    Manos Garai


  68. I want help in selecting a dtmf chip that works with a microcontoller and dials a specified phone number given by the microcontroller so that a pre-recorded audio message on a playback device can sent to the remote location by the public phone lines.Please any form of help including microcontroller selection,schematics diagrams or program source codes will be appreciated.Thank You.


  70. anyone please give me the step by step process to build Alarm Phone Dialer – uses MT8880 and PIC 16F84A. i need the code that will be set in the microcontroller. can anybody give me this please. my email address is tahsinakash06@gmail.com


  71. Hi Tahsin,

    You will have to follow the first link in the article to go to the creators page. You can then ask for this information there.


  72. Hola, te comento que no manejo el ingles.
    En cuanto a tu circuito no lo prove, pero pronto lo hare.
    Te agradesco tu mail,
    En cuanto lo arme te comento como me fue.Gracias


  73. You can tell me more about this circiut works, I need it for my license project. And where I can find the programer for this circuit.


  74. Hola, todabia no lo pude armar por falta de tiempo, le agradesco por su preocupacion, muy pronto lo armo y le comento que me parecio desde ya muchisimas gracias.


  75. Hi Alan,

    I would like to build this project for school. Is it possible if you could forward me the asm file?

    Rgds

    Titus


  76. Hi Titus,

    Click on the link in the article and look for the download. It includes the HEX file.


  77. I need the asm file. Please can you give me the asm file.


  78. I can’t understand for what it is the circuit from pin RAO


  79. Hi Stefan,

    You will have to click on the link and ask the creator if the code is available and what the pin is for.


  80. Hi!
    To Stefan
    With that pin(RA0) you can choose, what kind of dialing you want(pulse dialing or tone dialing)PS. In many countries you cant use pulse dialing anymore. You can find more information from google. My english is bad, sorry!


  81. Steven you are the author of this project?


  82. nop, but I`m building that too, I got the dialing tone, but it`s not calling. The dialing tone is little bit silence, so maybe this is the reason.


  83. Who knows who it’s the author of this project.


  85. Can this be linked to a fire/smoke alarm?
    How?
    thasnks!


  86. To Dave comment number 1: You’ve been watching too much TV. A real burglar is young, dumb and in a hurry to be too complete in cutting a phone line.


  87. why can you not replace the mt 8880 with a wireless dail chip.and which cheap ould it be.


  88. Friends ,, I finished building this project and it works like a charm…

    The only problem is that when the first number is being called it should open and close the relay after the call session in order to establish a new call and get the dialtone. But it keeps continously keeps dialing inspite of the * and # symbols programmed.

    I am checking the program after disassembling the hex…

    Lets see how far i troubleshoot >>

    Meanwhile has anyone faced the same problem … ??????

    Regards,
    Sunil…


  89. I would like to use this for an alarm system so that when motion is detected, it will call my phone. Does that activate from an alarm dry contact.


  90. How much is this circuit?


  92. can this be used to sense the vibration during the starting of a diesel generator remotely?


  93. Generators usually have a run contact that you could tie into directly.


  94. I am looking for a cellular device that basically replaces a copper wire attached telephone to a security alarm panel. It must be able to initiate and dial a predetermined number (the security service), when answered act like a regular telephone allowing the alarm panel to send to the security company. The purpose is to eliminate my copper wire $40 – $50 / month and get a GO phone or one of the $9.95 family plan wireless numbers.

    There are several that all range from $300 – $500 for the hardware and then there are increased monthly monitoring costs ranging from $5 to $20 over and above what you are currently paying.

    This device only has to look like a regular telephone to the monitoring company.

    Any help locating this is very much appreciated.

    Thanks

    Fred


  95. can any one tell the aproximate cost??


  96. It isn’t a matter of cost, I am interested to see if there are any and what their costs are.


  97. Any friend just send me the author of this project. I love to make your DTMF Phone call alert project. Or otherwise Please send me the real size PCB mirror pattern in BACK & WHITE image so that I can make it with toner transfer method.


  98. Hello Friends,

    I have this module and it really works superb.
    I have just altered the components which works well for Indian Standards.
    The approx. cost of the above project will come around Rs.240.
    As far as the transformer is concerned i desoldered it from an old 56k dial up modem.

    For achira::
    Try using Eagle S/W for pcb image. Moreover its a simple project try soldering it in general pcb. I tried it in a bread board and it works good.

    For Arun::
    This module works only on direct telephone land line connection. Its just a module where you can implement this thing anywhere wherever you have a telephone land line. This module can be interfaced with any control system.


  100. pleASE PLEASE

    GIVE ME THE FULL DETAILS, I CANT UNDERSTABD WHAT TO DO, CAN SOMEONE TELL ME OW TO OPEN THR ZIP FILES AND WHERE CAN I BUY THE CIRCUIT, LIKE TO PRINT THE CONNECTIONS.
    THANK YOU
    D


  102. Nice project! I just needed the phone line interface part and it works great. But I have a question about the .01uF 150V cap. I can’t figure out what it does! When the relay closes it is shorted out. With the relay open, you are on-hook and don’t need anything going to the isolation transformer.

    It seems it would only make sense if you need to monitor audio when on-hook. What am I missing?
    Thanks for any explanation.


  103. @BroHogan

    The 0.01uF cap is a coupling capacitor. ( allows only the ac signals ) so that the phone draws no current when it is on-hook.
    But exchange circuitry can send an AC voltage down the line to activate the ringer for an incoming call.
    Its 150V cuz the telephone voltage during ring on ,on hook and off hook, the average voltage might reach above 100V (depends on various countries).

    **And by the way you dont need to monitor the audio when on-hook.
    Instead its on off-hook.During on-hook it waits for the ringer signal(AC signal) then sends a dc signal back to the exchange to stop the incoming ringer signal from the excange.

    The isolation transformer provides impedance matching so that proper communication takes place.
    i.e. The numbers dialed from another phone for feeding into the microcontroller’s eeprom should be properly processed by the microcontroller.
    Instead of an isolation transformer you can make use of any impedance matching devices.
    Even optocouplers do good.


  104. Muris, thanks for the reply – that explains it.
    I eventually went with a “DAA” as the phone interface. That turned out to be a much more solid interface for me. You can see details of the project at:
    http://brohogan.blogspot.com/


  105. hello, im going to do a project like this. can you sent me the program to learn some phone numbers which this module will call after detecting an input on it’s sensor pin.
    thanks alot.
    by the way, can it be wireless?

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