Bluetooth Module BTM-182

Hello all i recently obtained a BTM-182 from Sparkfun. This is a Bluetooth module.

This module is super easy to get up and running, even though i ran into a issue. The issue i had was on my part, i was writing to the wrong port.

Ok i wont go into details about the module because you can find the info on Sparkfun.

What i will give you is some basic information to get started using this with a PC. Once you can use it with your PC you can use it with a AVR, PIC or ARM without issue.

Lets take a look at the pinout:

Looks like a lot, i know. Dont worry most of these pins wont even be used.  The only pins we need to worry about besides POWER pins are…


There are some LED’s we can also which are:

Link Status – PIN 22
Data Status – PIN 24
Power Status – PIN 28

These are vital for debug use. They are not needed really but can help you figure out connection and power issues.

Knowing the pins required we can now make a small development board for breadboard use:

Ok With this board created we can connect to a MCU or PC. The protocol is UART and the default config is:

Baud rate: 19200 bps
Data bit: 8
Parity: none
Stop bit: 1

You can simply use a MAX232 to connect to your PC and talk to the device via Terminal program or you can connect to a MCU like this:

The device uses simple AT command to configure the device.  As for example we will change the name of the module. You can get the name from the module by sending


This is AT Command N? which queries the device for its name. The max characters for the name field is 16.

To change the name to “AtomBT” we have to send “ATN=AtomBT”

Its simple as that. If you are getting errors or no data from the device try sending “+++” this is a SWITCH to command mode command. It will leave data mode and enter command mode.

29 thoughts on “Bluetooth Module BTM-182

  1. Wow, Jason!
    Thanks alot, man!!!
    I just started reading it and just had to write you a BIG thanks.
    This will help me alot….
    Really, I mean it.

    1. no problem. Sorry it took long. I blame DealExtreme heh took a month for 2 bottles of solder paste.. i also blame me for getting the cheapest shipping. 🙂

      Your Welcome!

      Im glad i could help.

  2. Hello

    would wish to know the way you are making your pcb , are you using toner transfer method , or photoresist method , as i am using toner transfer method but , the reults are not as good as yours as some times the toner would smuldge,and the edges are not always very sharp but i believe that the photoresist method would be much cleaner and sharper than this , also if you can comment on some links to buy photoresist online
    Manish jain

    1. Hey Manish,

      First let me say thank you for visiting the blog and saying my boards look nice. I actually use the Toner Transfer method also. Its a great quick way. I use Pulsar Paper from

      Its awesome and comes out perfect almost 100% of the time.

      If you are are having issues with toner transfer it may be because of a couple reasons:

      1. Bad or Little Toner. Ensure you are using GENUINE TONER and not refilled.
      2. Brother Laser Printers SUCK! dont use a Laser Printer from Brother. There toner i hear requires way more heat to remelt onto PCB.
      3. Are you Laminating or Ironing? If laminating ensure you pass it through a few times to thoroughly heat the PCB and melt toner. If Ironing make sure you apply enough pressure to PCB to make good contact.

      1. Hello

        and thanks for the super fast response ,for the smallest general query even ,

        I am hobbyist in India Delhi . So may be its the paper which is the differentiating factor as when i saw at their web site they say that the dextrin coating easily dissolves when immersed in water whereas in my case i have to peel of the paper, which i think is creating the problem my setups goes as below , and yes if you can also comment on where to buy photo resist online?

        1. Bad or Little Toner. Ensure you are using GENUINE TONER and not refilled.
        As I am using HP printer with genuine ink so it should be ok
        2. Brother Laser Printers SUCK! don’t use a Laser Printer from Brother. There toner i hear requires way more heat to remelt onto PCB.
        Hp printer with genuine ink
        3. Are you Laminating or Ironing? If laminating ensure you pass it through a few times to thoroughly heat the PCB and melt toner. If Ironing make sure you apply enough pressure to PCB to make good contact.
        I am still ironing and applying lot of pressure also , and sometimes the results are good but not always , may be its the paper peeling step which is creating the problem will check on pulsar paper and get back to you
        Once again thanks for the info shared

  3. Hi Atomsoft,
    I have just put my btm182 on my breadboard with a max232 but when I send it commands through the Uart pins it doesn’t seem to respond.

    If is short the t1in and r1out pins of my max232 chip i can see the characters returned to me so i dont think there is a problem with my max chip.

    I have connected
    R1out (max) –> Rx (btm)
    T1in (max) –> Tx(btm)

    I have a VCC(btm) = 3.254v
    and all the GND pins connected.

    Which terminal application are you using on the computer? Ive tried br@y++ terminal and hyper terminal.

    Any help would be great.

    1. Hello, TX from BT has to goto RX of MAX232 and RX from BT has to goto TX of MAX232

      I use hyperterminal. Ensure the settings:

      The factory settings of UART are as follows:
      Baud rate: 19200 bps
      Data bit: 8
      Parity: none
      Stop bit: 1

      1. Hi again,
        I have swapped those around but I can still not get the btm to respond.

        I only have 4 wires attached to the btm

        When i power on the device I can “see” the voltage change with the multimeter where the led is supposed to flash so I assume it is powering on correctly.

        Are any of those resistors and LEDs required to get the device to turn on correctly?

        Other than that i’m just about out of ideas.

        1. Hello can you email me with a schematic or something so i can double check what you have? Or a picture of the breadboard? So i can see the connections.

  4. Hi,
    Thank you very much
    I built the board in a couple of hours (and it worked!)
    To do the PCB transfer, used the cheapest method…. using TV magazine glossy cover page instead of photo paper (first try did work)

    Now a stupid question: Is there a way to reconfigure the board sending data through the Bluetooth Link (rather than a wired link to a PC)

    Again thank you for the tips!

    1. Your welcome! Magazine paper works well!

      Thats not a stupid question really.
      Ok to program the BT device you must do it through WIRE… now this is easy you can simply tell the PIC to do it.

      So its not that hard really just confusing a bit… Ill see if i can write some code today to show you.

      1. Hi Jason,
        Thank you for the reply
        I stay tuned
        When you set up the BT module through the wire connection, does it keep the settings if you remove power?

        1. Been busy today but will make something up soon. Um yeah the module saves the data. I renamed my BT to AtomBT and removed power and waiting 1 minute and when i powered it back it was still there…

  5. Hi Jason,
    Now we know why you are busy, congratulations
    If we don’t ear (read) about you we will not worry


  6. Hi Jason,
    Saw your blog link on sparkfun. I have a question about the BTM-182 and cant seem to find info about it, maybe you can help. Can this be used to stream music to BT-enabled headphones? Im thinking of starting a project to design a simple board that can stream music from a headphone jack through BT to store bought headphones. I have a sparkfun forum thread started (, is this possible with this module? Thanks

  7. Hi,
    I have one of these BTM-182. The datasheet shows the command ATL8 to set baud to 921600, do you know how to set it higher than this??? If not with UART, how to communicate with it to take advantage of the 3Mbps??
    Thanks for any info

      1. I also have the btm 182 but cant set the baud rate to 921600. Every other baud I have programmed but need this max val for my project. I have to find a replacement bluetooth if I cant set this baud. I did notice that the btm 182 data sheet is very very similar to the btm 112 with the only difference being the the command ATF L8 does not exist on the BTM 112. Any help greatly appreciated

  8. Ok, i gave it a try and i get a error when trying to use L8 which is 921.6Kbps. I assume it is not implemented in the firmware so i asked at sparkfun product page. Hope fully someone can get back to me so i can inform you guys. Sorry about that.

    1. Thanks thats ok. I am probably going to go ahead and order the WT32 by bluegiga since I am running out of time. I dont understand why ATL8 wont work but at least I know its not just this module but everyone has the same problem. If anyone is feeling ambitious they could put an LSA up to the module and check and see whats going and if its a hardware problem or whatever.

  9. Hello! Thanks for this materials! I done something and got some problems. Could you give me some advice, please?
    First of all:
    I connect BT182 to MMusbMCP2200. I use Termite 2.9. If I send anything to module from PC with default Termite settings (the same like settings of BT182, ofc) the only sing I see is echo. BT182 answers by this to any command I send to it. Even to “+++”. But whe I connect my tablet to BT182, they can see each other, and the can recive and transmit data. I can see it in Termite window and in tablet. So the question is, what wrong I do with sending of commanads?

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