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Which protocol for low latency, low power, high rate motion tracking application?

Hi

my application is a 9-axis battery driven motion sensor with a data rate about 144 bit per packet at 1000Hz i have to transmit over air. Low latency (<10ms) is extremely important. The device must consume as low power as possible due less space for a battery. The protocol can be proprietary but must support 6 nodes connected to a master at a time.

Which protocol to choose for

low latency low power high data rate

BLE isn't right choice because of small packet size and to long connection interval. BT classic is performing better but consumes more power.

What about ANT or Gazell?

  • Hi

    I think BLE and ANT is out of the question immediately because of the data rate requirements, and you will have to go for some type of proprietary solution.

    Gazell might work, but here you are also pushing against data rate limitations if you need to send one 18 byte payload from 6 sensors every 1ms.

    If you go for a completely custom solution you can customize the protocol to your particular requirements, and with direct access to the radio it is possible to send payloads up to 255 bytes, allowing you to buffer and send several 18 byte blocks in a single payload to reduce the protocol overhead. This will give you the best technical solution, but it requires you to write the protocol yourself which will increase development time.

    How much experience do you have with C-programming and RF protocol development?

    Best regards Torbjørn

  • Thanks for your reply.

    Buffering is not really an option, due low latency requirements. The motion tracking application need high data density (1kHz) and low latency over air (<10ms).

    What if i split the star network with 6 slaves connected to a single master in a 3 master 2 slaves or even point-to-point network? This would reduce data rate to 1/3 or 1/6.

    Is Gazell supporting coexisting networks on different channels/frequencies? What are the minimal connection intervalls with Gazell?

    I don't have much experience in RF protocol development. So don't want to set up a protocoll stack from scratch. I prefer to use a ready stack with an API.

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