Choosing between Bluetooth 4.0 and Classic

[Twistx77]

Hello,

I'm working in a device which is already working using a cable but now I need to add a Bluetooth link so you don't need to use the cable. The devices is battery powered but I don't know exactly which kind of Bluetooth I should use.

I know that 4.0 or BLE is better for battery powered devices but I'm not sure if BLE will give me enough bandwidth for my application and also if BLE can send data continuously. I've read that the throughput with BLE is about 250kb/s which is just enough for my application since I'm already using 256kb/s with the cable. The thing is, will this speed vary too much with distance ( I only need 10 meters at the most).

So can BLE meet my requirements or do I need to use classic bluetooth?

I would appreciate any help.

Thank you!

[purfield]

I'm a total newbie here, but I've been playing around with BLE for a few months and from my experience, I would suggest that you go with classic bluetooth.  BLE seems to only be really power-efficient for very low bandwidth applications.  I've played around with some BLE development devices transmitting lots of sensor data at high sampling rates, and I can eat through a coin cell battery in just a few hours.  On the other hand, if you're transmitting tiny packets at very slow intervals, you can get a few years of use out of a coin cell battery.  It sounds like for your application, classic bluetooth would be the best choice.

[andyturk]

The main difference between BLE and classic is that BLE keeps the radio off most of the time. That's good for battery life, but not so good for throughput. As purfield said, if you need to send a lot of bits, then classic is the way to go.

The real-world throughput of a BLE connection is a lot lower than 250kb/s. The actual number is dependent upon the "connection interval" which is determined by the slave side of the connection. Most likely, your gizmo is actually the master, so the other end determines how often the radios turn on and send bits. When they do turn on, BLE limits you to 23-byte packets.

On the other hand, BLE is handy if you're talking to iOS devices, which require a special crypto chip from Apple for classic. iOS devices will talk BLE without the crypto.