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Smart Bluetooth

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I try to evaluate 920737s by using SDK2.2 speed_test example runs with Window peerapp SpeedTest client to figure out what is the max data rate, I notice some posts on the forum has mentioned the data rate can be as fast as 80kps but my finding is far below, please see what I got from the procedure I did below.


What I got today by running SpeedTest Window client application with speed_test on tag3 board is somewhere around 13.5kbps max.

The limitations that stopped to have better data rate were the SOC itself stopped after data bashing for a little while, I expected it should send and loopback on receive what has been sent infinitely or at least up to me to stop it. It however stop by itself to storm the BT media even I set it for storming forever using forever while loop in firmware.

I wonder what tricks I can have to get it running infinitely (though is not a real use case that no scenario could keep to storm BT media forever in real life, but this test though unrealistic, could show me logic could suck every single bit of juice out of the SOC to serve for data storming and  from the results I can capture in wireshare can show me the theoretical data rate)

Attached is the wireshark  file and a screenshot below.

This performance data rate research is essential for what should be the right candidates.



It did succeed to continue sending data in chunks of 20 bytes (limitation of Android read/write characteristic value size) back to back but it stopped to storm for a little while, this may be due to characteristic configuration setup, or may be related to falling back to low power mode or firmware logic that has exception to exceed the while loop… still not sure and need more debugging.


Max performance data rate record = 13.49kbps.

1 Solution

I spoke to several people that were able to get this app running right out of the box and they said that they were able to achieve in the 70Kbps range.

One told me that they did modify with the connection interval request rate as that definitely had an affect on the throughput; out of the box the speed_test app requests a 7.5ms connection interval.

Thinking....I know that if you are using Windows 8, it uses MSFT’s stack and not BTW, and supposedly the MSFT stack doesn’t let you go below 15ms on the connection interval.

I cannot recall if you were using Win-8 or not.


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