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Author Topic: Bluetooth chip EXPLODED (or not?)  (Read 399 times)
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Hi!
Couple of weeks ago i bought a cheap bluetooth module from e-bay.


http://www.ebay.com/itm/TTL-Bluetooth-Module-Arduino-uControllers-/330632884570?_trksid=p4340.m185&_trkparms=algo%3DSIC.NPJS%26its%3DI%26itu%3DUA%26otn%3D5%26pmod%3D230689344642%26ps%3D63%26clkid%3D3891958372673248975

When i received it, everything worked well.
Today i soldered some pins to the module and plugged it in to my breadboard.
Then I uploaded sample code to Arduino. After double checking everything, i powered it on. But nothing.

The only thing that works, is that my phone makes successful connection to bluetooth module. I can tell this, because bluetooth module stops blinking (searching, announcing) and my cellphone says it is connected.

I uploaded sample script that should take my compass readings and send them to Arduino as an integer "time led blinks". I also tried another script that worked well before, but no luck.

Is it possible, that although bluetooth module creates successful connection to my smartphone, it is not able to send commands to Arduino?

Someone wrote in another post that bluetooth module's RX, TX work with 3.3V, but Arduino's RX, TX pins work with 5V, so definitely should use resistors.
- Unfortunately I forgot this crucial aspect and connected modules RX / TX straight to Arduino pins  smiley-confuse


« Last Edit: November 17, 2011, 05:47:10 am by D3C3PT1C0N » Logged

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Quote
Unfortunately I forgot this crucial aspect and connected modules RX / TX straight to Arduino pins
Yes that could explain why the module itself works but you can't communicate with it.

But the web site says:-
Quote
Note:  TX and RX are LVTTL, meaning 3.3V signals.  While I have tested the module extensively directly using the 5V TTL signals (Arduino for example) with no problems, I cannot promise that damage will never occur, and it is therefore recommended to use transistors to interface with a 5V TTL signal.
« Last Edit: November 17, 2011, 01:00:37 pm by Grumpy_Mike » Logged

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Well... there goes my 11 euros smiley-razz
Next time I should read before diving in  smiley-mr-green
At least it wasn't Arduino BT , that costs 114,00 € in a local shop.
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