Advice on picking the right components (lilypad, IMU, Bluetooth BLE)

Hello guys, I need to create a wearable prototype that will need to read data from an accelerometer/gyroscope, probably perform some DTW algorithms for gesture detection, and upon successful detection it'll need to ping an iOS device.

First things first, since Apple's has not made the whole Bluetooth stack API available but only the BT4.0-BLE part, I'll need something that talks BLE. Did some searching and stumbled upon the BLEBee v1.0 ( which seems to communicate over standard serial tx/rx. So, we'll need a main board being able to accommodate that.

Second, I'll need a solid IMU. I am not really sure yet if only an accelerometer can provide accurately pitch and roll data while in the same time monitoring some "shake-y" up and down movements. So betting safe, I think I need to go for an integrated IMU. Either this ( or this ( seem fine although can't really understand the differences. Except from the later having that "one INT output pin from each sensor is broken out." which frankly I have no idea what is used for. So either way, they talk over I2C SDA/SCL if I understand correctly, so the board needs to be able to accommodate one of these as well.

On to the boards, I am considering the Lilypad family due to compactness and relatively small size/weight. The most tempting choice is going for [u]LilyPad Arduino USB/u mainly due to the integrated JST and LiPo charging circuitry and the integrated USB interface. It also has SDA/SCL for the IMU. However, by taking a look at the schematics it seems that there's no mapping of the ATMEGA's rx/tx on the board pins so I am assuming I won't be able to facilitate the BLEbee?

As an alternative choice I am also considering [u]Lilypad Arduino Simple/u that seems to have both tx/rx available as well as SDA/SCL for the IMU and JST for LiPo battery. However, I assume it needs some sort of externally pluggable FTDI to USB adapter for uploading the code as well as for printing "always-on" realtime debugging info on a console (I came from strong software background, this is essential for me to develop the software for the prototype). BUT it says that "Because of the battery charging circuit, it is not possible to power components like a bluetooth modem via the FTDI connector." which means that getting BLEBee to work while at the same time getting console messages on my pc via the FTDI2USB is a no-no? So the BLEBee will be powered only if the whole system is not plugged-in with USB onto my workstation? Or the BLEBee can be powered by the LiPo battery while it's being charged by the FTDI adapter? Definitely need some advice on that.

Wrapping up, ideally, I want something that will be able to facilitate both an IMU and the BLEBee (rx/tx, SDA/SCL), will have a JST for LiPo battery with charging circuitry and at the same time will be able to stay connected via USB with my workstation for debugging/developing.

Looking forward to your suggestions, I appreciate your help in advance!


Best Regards to everyone

EDIT: utterly complete newbie on arduinos and stuff, embarrassingly minored EEng


I'm looking for exactly that. I did some research for prebuild settings and found the following:

This does what I want but is quite expensive for my purposes. Did you make some progress in your idea?

Best, Felix