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51822 bluetooth


Using 51822 with BLE stack, I was faced with the problem of low transfer rates (5kb) on my android device (phone). It is very slow.

Can work 51822 with standart Bluetooth (not BLE)?

  • Hi Kristin, I think your comment regarding the packet limit needs some clarification:

    On the PHY, the max data packet size is: payload 27bytes + the 4 byte MIC + 2 byte header + 1 byte preamble + 4 byte access address + 3 byte CRC, in total this is 41bytes = 328 bits, this takes 328us on the PHY. So if both the master and the slave sends these maximum size packets back and forth in the connection event, then the maximum number of packets (x) in each direction at maximum packet has to satisfy 2 * x * (328 + 152 (max. IFS)) < connection interval [us]

    Even at 7.5ms this is 7 packets, but there is no reason the LL can not send more packets than this if the connection interval is longer if I'm not mistaken.

  • It is true that there is theoretically time to transfer more packets, but the S110 supports maximum six packets per event, no matter how long the interval is. This has to do with RAM usage for the internal buffers.

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