bluetooth bracelet

[pongWiz]

i am thinking about building a bracelet that contains a couple led that light up whenever i have a text message or any other type of message. i have a teensy board that is pretty small and i was thinking about connecting the board to a bluetooth dongle. problem is i havent done enough research on the dongle and dont know if it is going to work as planned.

[UAirLtd]

I assume you mean a Bluetooth-to-serial module, in which case you're talking a basic serial connection. You would then need to code something for your phone to interface with a bluetooth SPP/RFCOM device, which as far as I know is reasonably common thing to do on Android. If you were thinking of using a small USB-bluetooth module, then I'm afraid you were mistaken, the Teensy does not handle USB Host that is required to interface with one. Other, more complex options possible for sure, but you wouldn't be using a teensy.

Of course, you could also just get one of these: http://www.amazon.com/s/ref=nb_sb_noss_ ... h+bracelet for $20

[pongWiz]

can i use something like this to receive a bluetooth signal from my android power phone?

https://www.sparkfun.com/products/10253

[UAirLtd]

Yes, android has support for SPP and more.

[st2000]

i am thinking about building a bracelet that contains a couple led that light up whenever i have a text message or any other type of message. i have a teensy board that is pretty small and i was thinking about connecting the board to a bluetooth dongle. problem is i havent done enough research on the dongle and dont know if it is going to work as planned.

If I were you I would let the IOIO board take care of all your problems:
https://www.sparkfun.com/products/10748
1. The on board PIC is already programmed to work with an Android device.
2. It is also ready to work with most (probably not all) USB bluetooth dongles. Most of which can be had for well below $10.
3. It is also ready to connect to just about anything (i.e. digital out, in and analog in).
4. On the android side, I am lead to believe there is a "grocery list" of methods waiting to be called. I believe the author was attempting to make Android programming for the IOIO as easy as C programming for the Arduino.

...I can see not only creating a vibrating bracelet, but adding, maybe, an OLED to display numbers.

Of course this is not cost effective. As UAirLtd pointed out you can buy a bracelet with a display for under $50. Where as the IOIO board will cost $50 plus you will have to spend a few more dollars on the USB Bluetooth dongle. Not to mention, you still need a way to generate the 5V expected by the USB Bluetooth dongle and IOIO board.

Ah! The portability (not bracelet) power problem has been solved!:
http://www.adafruit.com/products/885
...and you can probably hide the vibrating motor in the metal tin as well!

Edit: added later
I just noticed the Adafruit version includes a bluetooth dongle. So, from what I understand, all you would need to do is add a vibrating motor that can be controlled by the PIC. So, maybe, to be safe, you would add a circuit to drive the motor to go between the PIC and the motor.

-good luck

[Quin]

If I were you I would let the IOIO board take care of all your problems:

Why use a IOIO? It seems the author wanted Bluetooth from phone to bracelet-like device, and if the phone has a bluetooth radio built in adding an IOIO would just complicate things. The SMD BT module linked is easy enough to configure from a small microcontroller, and will pair with a bluetooth phone easy enough. Writing an app on the phone to listen for txt or calls and send a serial notification might be a trick for beginners, but not impossible.

[st2000]

Why use a IOIO?

Because the IOIO already has code to support a cheap Bluetooth USB dongles at one end and is peppered with IO pins at the other to control anything from a vibrating motor to a tiny OLED display for caller I.D.

Ok, let's say we are going to use the USB Dongle from Sparkfun.com instead of the IOIO board w/a cheep Bluetooth USB dongle. Despite what Sparkfun says, people have been commenting that it only supports SPP. That's ok for Androids, but probably not for iPhones. (Apple is very tight w.r.t. features. I think they only allow HID, HSF & A2DP) Let's say you don't need to type anything into the Bluetooth dongle in order for it to pair with the phone. That may or may not be true. (Can anyone clear this up - when paring requires a random string to be returned from the paired device as specified by the "other" device?) So if we have managed a Bluetooth SPP connection between the phone and Sparkfun device, we should be able to send a character to the device. So now we need some processor or combination of logic to decode the serial port character. I was going for the PIC on the IOIO board. And then thought to reduce the cost of the Bluetooth device from about $15 to about $5 by switching to a Bluetooth USB dongle.

OTOH, these Bluetooth boards like the one from Sparkfun are complex devices running their own software. If you happen across one that is "more open" as to how to program it, there may be a chance that you could get all your features out of just the Bluetooth device. This would be ideal. But so far, I have found nothing w.r.t. altering the features sported by the COTS Bluetooth parts. So far, I have only seen SPP, HID and one that could handle a switch matrix inside of a Bluetooth keyboard. Do any here know of one that contains general purpose I/O pins. And if so, a good description of how they work?

[UAirLtd]

Ok, let's say you're ok for SPP because you're using Android ( as per "can i use something like this to receive a bluetooth signal from my android power phone?"). Jailbroken iOS also works. You get one of these bog-standard cheap Chinese bluetooth SPP modules http://www.ebay.com/itm/30ft-3-3VDC-Wir ... 53ea973181 and you attach one resistor and one LED to the TX line, maybe an LED and resistor to the Activity line. (Don't forget, Sparkfun do try to make a profit, things they sell aren't necessarily the cheapest around)

On startup, the module enters pairing mode (or you can force it into pairing mode via the reset/pair pin), you pair it to your phone, entering 0000 for the code. Now you're connected, send any message and the TX line outputs some data that causes the LED to flash. This fulfils the basic OP requirements of "i am thinking about building a bracelet that contains a couple led that light up whenever i have a text message or any other type of message."

Now, suppose you want more complexity? Attach any low-cost microcontroller board that has a TTL UART, like any of those *duino boards out there (femtoduino, tinyduino, digispark, nanoduino, etc. etc.) Total cost is about $20 and it's significantly less complex as you just deal with pure UART data, and not have to worry about the USB Host stack and the BT stacks as you would the IOIO. For this project, such a set-up would be sufficient unless the user already has a IOIO knocking around, or is familiar with the workings of the IOIO USB Host and BT stacks.

Of course, some people are after end-results rather than the fun and educational purposes of building something for themselves, for such people, a consumer electronics device such as a bluetooth bracelet: http://www.amazon.com/s/ref=nb_sb_noss_ ... h+bracelet is still cheaper than a IOIO

[chinaok321]

I don't think it will work when messengers arrive, but when callings incoming, the system of cellphone will give bluetooth signal to third device. That is why the bracelet work.
while messengers arrive, how the cellphone know to send signal to bT bluetooth bracelet? reference to this manufacturer http://www.computerusb.com/index.php?ma ... x&cPath=78 they are latest design and creative.