Increase speed on RN-41 bluetooth SPP?

Question

I'm using RN-41-APLX bluetooth evaluation board (based on RN-41-APL, very similar to RN-41 but also supports Apple devices) as a member of MFi.

I was able to establish connection and transfer some data to and from dev board with out-of-the-box configuration.

The problem is, in data sheet for RN-41 it is set, that SPP profile supports 240kbps speed, but when I transfer 10kB from iPod touch with Roving test iOS application installed, it takes 5 seconds to transfer.

Since UART speed is 230kbps, I think the bottle neck is the bluetooth link speed, but I can not find any way to change it. Can anybody help with that?

Thanks in advance!

Answer 1

I've run into this problem myself about this chip (well, the RN42 technically) and posted my findings here: RN42 Bluetooth disconnects on iOS within seconds of streaming data

Short summary:

When the RN42 is used to communicate with an iOS device, it cannot communicate faster than 2.5-3kB/s... If it's used to communicate with an Android or computer or anything else, it can transfer at 35kB/s (over SPP).

Hope it helps!
-SJ