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Why Won't The Bluetooth RN-270F Stay Powered On? (Answer: Read On!)

I have a SkyBT that works great.  Since it looks like the SkyBT will no longer be available for purchase from Simulation Curriculum and after reading that the SkyBT is simply a rebranded "FireFly" Bluetooth to serial adapter from Roving Networks, I decided to order one as a backup.  I received my RN-270M today and I think it might be defective but I want to hopefully get some help troubleshooting it.  I confirmed that the DIP switches and jumpers are set the same as my SkyBT.

When I power up the RN-270M, this is what happens...

1.  The blue and green LEDs blink quickly.
2.  The green LED blinks 10 times.
3.  The blue and green LEDs blink quickly.
4.  The device powers itself off.

I was able to verify that it is broadcasting and available for pairing for the brief period of time that the green LED is blinking.  I get the same result whether using NiMH batteries only or batteries plus external power.  The red LED does light up when external power is connected.

Again, my SkyBT does not behave like this.

Any ideas what to try for further troubleshooting?



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    Flashing blue light almost always means low power.  The blue light flashes indicating low power, then it shuts down.

    When you power them externally (which I do in the winter because the only batteries that work in the cold are the expensive Energizer Ultimate Lithium ones), I too get the red charge light all the time.  And I get the flashing green or yellow ones indicating connection status and communications.  I don't get the blue one when on good external power or when the internal batteries are good.

    You probably know this, but external power should be 5v DC, and you MUST use rechargeable AAA batteries in the SkyBT/RN-270 when powering either externally.  But since you said you were using NiMH batteries in the device, that's good.  But they might not be fully recharged and/or any good.  If one of the internal batteries has a short -- external power probably won't go through it.

    Have you tested each AAA NiMH battery individually?  Each one should read at least 1.2v.  Mine usually read 1.3v - 1.4v..  

    If you're trying to use this system in the cold, that could be the problem.  But if the same batteries work in the SkyBT and not the RN-270, then the batteries are OK.

    You shouldn't need to flip any of the DIP switches in either unit.  They "should" come in the proper default configuration -- and that default configuration is the same for both units.

    If your same batteries work in the SkyBT and not in the RN-270, it sounds like you've got a bad RN-270.  I use mine interchangeably.  They're identical.

    Oh -- not completely identical.  They will have different Bluetooth "Firefly ID" numbers.  So when you switch devices, you have to switch the Bluetooth "Firefly" number in SkySafari too.  If you've paired both devices, you should now have two Firefly devices in your list -- but the numbers after "Firefly" will be different -- and you have to match them up.

    But it does sound like that's not your problem either.  Again, the flashing blue light almost always means low power.


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    Steven Marty

    Thanks for the quick reply.

    Just to clarify, when powering either unit on or off, the blue and green LEDs flash alternately very quickly.  I believe this is the standard "power on" and "power off" LED dance.  The new adapter is powering up OK, it basically just doesn't stay powered on.  After 10 flashes of the green LED, the device does the "power off" LED sequence and then powers itself off.  I'm using the same set of batteries in both the new adapter and the SkyBT.

    Using a USB to serial adapter and a terminal program, I was able to dump the settings from both adapters.  There are three groups of settings - basic, extended, and other.  With the exception of the Bluetooth Address (BTA) and Bluetooth Name (BTName), the settings are identical between the two.  The firmware is also the same on both adapters.

    The item was packaged very well...protective bubble wrap sealed with "anti-static" tape in an anti-static bag, wrapped in protective paper, and all of that in a shipping box.  It just seems unlikely that the adapter would be bad out of the box but I guess stuff happens.

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    How were you able to keep the new RN-270 powered up long enough to get the data dumps?  I know these things can be self-powered through the serial connection, but I'm still surprised.  

    Something's odd.  It sure sounds like the thing works -- but then shuts down.  There's got to be a power problem somehow involving the battery/battery connections.  And it sure sounds as if you've gone way above and beyond what most people could do to identify the problem.

    I'd definitely contact Roving Networks at this point.  And then see about getting a RA number and exchanging it.  It should just work -- particularly with the same batteries.

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    Steven Marty

    I found that if I throw one of the DIP switches, the adapter stays on a little longer - enough for me to get the dumps - albeit in two tries.

    I also discovered that if I hold down the power button on my (working) SkyBT, the resulting LED sequence is exactly what the new adapter is doing.

    I tried to "Restore Factory Defaults" using the steps provided in the user's guide and the adapter doesn't reset properly.  I think it's just bad.

    As you may know, Roving Networks is now Microchip Technology.  I purchased the adapter directly from Digi-Key.  In case you don't have this already, there is a very complete user's guide available for download from Microchip...

    This helped me tremendously with troubleshooting.

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