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Topic: What's a good low-power low-cost Bluetooth chip? (Read 2395 times) previous topic - next topic

vputz

May 03, 2013, 02:16 pm Last Edit: May 03, 2013, 08:59 pm by vputz Reason: 1
...I'm designing a battery-powered bluetooth sensor, and I'm looking for the BT part.  I've used the RN42 before in the Sparkfun Bluetooth Mate Silver, which I liked, but at $11 it's spendy compared to the really cheap units I've seen (which may be worth it!).  I've seen a few projects with the BC417, which I've seen packaged with a little flash memory chip for around $6-7, which is cheap, but I'm looking for something I can SMD to a board with at ATMega32u4, and I got all confused.

What BT modules have people used with success that are fairly low cost and low power?  I'm just looking for something to send/receive serial that I can set the ID on.

Riva

#1
May 03, 2013, 03:10 pm Last Edit: May 04, 2013, 09:23 am by Riva Reason: 1
Are you looking for a USB chip as the subject suggests or a bluetooth module?
Most of the cheap BT modules you get on eBay are a standard BT board that runs at 3.3V, some are HC-06 (slave only) or HC-05 (Master/slave switchable). Some vendors have mounted these BT modules on a breakout board to allow for extra components to work with 5V and add LED status light.

EDIT: Corrected error in model numbering.

vputz

Riva:  I'm an idiot and this is what I get for posting while tired.  Bluetooth (edited title to fix).

But my problem is that I see cheap ($6ish) BT modules on ebay, but can't seem to find anything from a repeatable online vendor like Digikey or Farnell for anything near that price range.  Ebay's great for one-offs, but if I ever have to build 200 of something, I'd like to avoid it.

Docedison

try here... I searched for : " JY-MCU HC-05 Bluetooth Wireless Serial Port Module ' The HC05 can be master or slave as you know.. It's been superseded I think..
http://jymcu.en.gongchang.com/product/15032209
But this place should get you started  I've been on the MFR's website but I can't find where I saved the address

Doc
--> WA7EMS <--
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Nick_Pyner


some are HC-05 (slave only) or HC-06 (Master/slave switchable).


and


The HC05 can be master or slave as you know..



What can be made of this?

More to the point, how tell which is which?

Riva

Quote
What can be made of this?

More to the point, how tell which is which?

My bad, got the numbers the wrong way round (fixed in original post now). As to telling them apart, AFAIK they are the same hardware, it's just the firmware that determines there modus operandi as this guy has re-flashed slave only modules to master/slave modules.

Riva


But my problem is that I see cheap ($6ish) BT modules on ebay, but can't seem to find anything from a repeatable online vendor like Digikey or Farnell for anything near that price range.  Ebay's great for one-offs, but if I ever have to build 200 of something, I'd like to avoid it.

Mouser have some BT modules that may suit your needs but your talking $15-$20+ each.
This company looks like it can sell in large quantities at $8.76 per unit in 100+ numbers.
This lot also look like they may do large numbers at $4.20 per unit or less.



Nick_Pyner


As to telling them apart, AFAIK they are the same hardware, it's just the firmware that determines there modus operandi


The connections to the backplane are different but I think you only find out about that when you've got it wrong.

Riva


The connections to the backplane are different but I think you only find out about that when you've got it wrong.

Yes, if you have a box of mixed modules you have to connect them up to find out the firmware version. Before a BT connection is established you can send AT commands to both versions but the line termination is different depending on the firmware you have. HC-06 (Linvor) firmware does not want CR/LF line termination but HC-05 needs CR/LF to line terminate.
You could connect up the basics VCC, GND, RX & TX send a non terminated AT command and see if you get an OK (HC-06) if not then send AT with CR/LF and see if you get OK (HC-05)

pito

Low power(?): my HC-05 cheapo ebay master/slave modules take 40mA when pairing, 20mA on active tx/rx and 3mA when idle (no uart activity for more than 5secs, this option depends on the firmware). Not sure it is "low power", however  :~
Maybe you are targeting "Bluetooth low energy (BLE)" modules - http://en.wikipedia.org/wiki/Bluetooth_low_energy
p.

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