Increase Bluetooth notification rate

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kendogar
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Increase Bluetooth notification rate

Post by kendogar » September 14th, 2021, 2:46 am

Hey everyone,

I am new here and am trying to write a small analytics tool for my PM5 rowing machine, mainly because I am interested in working with bluetooth and the live data.

So without changing anything, upon subscribing to the general status characteristic (0x0031) or the additional ones (0x0032 and 0x0033) the notifications arrive in 900ms to 1s intervals, which is quite slow I believe.

Then I've stumbled upon the 0x0034 characteristic, which should let me be able to change the notification rate according to the attached table.

Now my issue is, writing a "2" (0x02) Byte to the characteristic increases the notification rate to approximately 250ms - 330ms, which is already much better. But I kind of wanted to increase the rate to 100ms which should work by writing the "3" (0x03) Byte to the characteristic according to the documentation, but that does not work. Writing 0x03 does nothing for me and leaves the rate at 1 notification per ~1s.

Am I missing something here? How can I increase the notification rate successfully to 100ms intervals?

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tijmenvangulik
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Re: Increase Bluetooth notification rate

Post by tijmenvangulik » September 16th, 2021, 1:51 pm

I think you do this correctly. I think you have to contact concept2 about this, they have good support. I am interested what the answer is since I use the same definitions in ergometerjs.

Tijmen

kendogar
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Re: Increase Bluetooth notification rate

Post by kendogar » September 17th, 2021, 5:02 am

So apparently the issue is fixed for me and I am now receiving notifications in an 100ms interval after setting the value to 0x03.

What I did?

I did move my rowing machine from the building services room to another room. That's it. As soon as I moved the machine, the data rate increased.
I have no clue why that is, but it works now and I am glad.

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Citroen
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Re: Increase Bluetooth notification rate

Post by Citroen » September 17th, 2021, 6:32 am

kendogar wrote:
September 17th, 2021, 5:02 am
I did move my rowing machine from the building services room to another room. That's it. As soon as I moved the machine, the data rate increased.
I have no clue why that is, but it works now and I am glad.
Bluetooth Low Energy is on the 2.4GHz Industrial/Scientific/Medical (ISM) band which is a crowded part of the radio spectrum which includes microwave ovens. Even with frequency hopping (as invented by the actress Hedy Lammar) any other ISM transceivers can affect your BLE transceivers.

Moving the unit to an area where the ISM band is less crowded or has less interference solved your problem.

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