Bluetooth transmission

[ritchie888]

I was hoping someone could direct me towards a device or suggestion to solve a problem of mine.

I have an inertial measurement unit which can collect and transmit its data via Bluetooth. Normally I'd have this communicating with a laptop which would have either a Bluetooth dongle or built in Bluetooth receiver. However, I need to now send this data to another device which has an analogue input so that all the technologies can be synced together. Previously I was trying to collect data from the two devices the best I could by tapping 'start record' on each device manually, but now I really need a way of starting all the devices by clicking the one main start button so all data is synced perfectly.

So, basically, I need a type of Bluetooth receiver, which has the ability of searching and finding devices (as the IMU has no interface) and then also has an analogue output which I can connect to the analogue input of the main device, I'll then start and stop recording via the main device. I can then decode the packets offline. I'm thinking some sort of audio device which I can use? However, I'm completely clueless.

Any suggestions will be most helpful.

 

[VEBill]

You know when they make movies they use the clapperboard? You should be able to use the same concept. Start each recording one-by-one, and then apply a short sharp signal to all recorders at once.

Your approach of replacing the laptop seems like it would just lead you in circles. You still need a computer in the middle; it might as well be a laptop.

You can of course record analog signals using your laptop. There are endless Analog I/O cards and dongles available. Clever software can synchronize the recordings.

 

[IRstuff]

Arduino boards have on-board ADCs and can daughtercard an Bluetooth "shield." Nonetheless, some of your problem can be alleviated through decent timetagging. Since you are only recording the data for later use, you only need to know the time of the data, and not strict time synchronization of the data.

TTFN
faq731-376

 

[VEBill]

Using a single board computer (e.g. Arduino) can of course work; but then the next day you'll probably realize that you actually do need a user interface and you'll be back where you started.

For an embedded application, a SBC is the obvious choice.

 

[IRstuff]

Arduino does come with a GUI for the commands/status and program downloads. Some typical apps send data to the GUI, which has a logging function. Otherwise, you'd configure a USB client that gets the data and you can then save it as you desire.

TTFN
faq731-376

 

[ritchie888]

Had never thought about using an Arduino, actually could work very well with a BT shield!

I could connect to the IMU using the Arduino, leave it idle and collecting packets, then use the main device to start/stop collection of the data off an analogue pin.

 

[VEBill]

"User interface" .NE. "GUI".

User interface meaning display, keyboard, maybe a mouse or a touchpad. For example, maybe a laptop.

If it's an embedded application, SBC is ideal.

 

[IRstuff]

Sure, Arduino's GUI runs on a PC, through a USB or serial. They have lots of open source examples of how the data is extracted from the data stream coming back to the PC.

TTFN
faq731-376

 

[IRstuff]

So, it looks like Sparkfun has a sweet deal, combining an Arduino with Labview student edition. With the appropriate driver installed, you get your data scarfed up by Labview and you can process it to your heart's content.

https://www.sparkfun.com/products/11225

TTFN
faq731-376