How to achieve the maximum transmission rate through ble_app_uart with IOS nrfconnect app

[helen]

Excuse me:

                      I want to achieve the maximum transfer speed between ble_app_uart and IOS NRF connect app，How to modify the example to achieve the maximum transfer speed with the app,Can we achieve a speed of more than 50kb / s?

[helen]

Ok，Besides MTU, are there any other ways to increase the rate？The device has requested to update the PHY to 2M. How can I confirm that the PHY has been successfully updated on IOS NRF connect APP?

[ovrebekk]

Hi Helen

Whenever the PHY is changed you should get the BLE_GAP_EVT_PHY_UPDATE event from the SoftDevice. 

Along with this event you get the following struct, which includes information about which TX and RX PHY you are currently using, and the status of the last PHY update procedure:

/**@brief Event Structure for @ref BLE_GAP_EVT_PHY_UPDATE. */
typedef struct
{
  uint8_t status;                               /**< Status of the procedure, see @ref BLE_HCI_STATUS_CODES.*/
  uint8_t tx_phy;                               /**< TX PHY for this connection, see @ref BLE_GAP_PHYS. */
  uint8_t rx_phy;                               /**< RX PHY for this connection, see @ref BLE_GAP_PHYS. */
} ble_gap_evt_phy_update_t;

Can you confirm what kind of throughput you are currently seeing, after taking advantage of the 182 byte packet length, 2M phy and 15ms connection interval?

Best regards
Torbjørn

[helen]

Hi

      I found a problem that used the smartphone of android 11 communicate with NUS of nRF52833，the rate is 60kbyte/s in BLE_GAP_PHY_1MBPS  mode，but the rate is 30kbyte/s in BLE_GAP_PHY_2MBPS mode.

[ovrebekk]

Hi Helen

In general I would recommend opening a new ticket rather than replying in a very old one, since the devzone is not really optimized for handling multiple questions in the same ticket. 

Which phone are you using for the test?

Could you try to capture a sniffer trace of the two cases, so that you can see why the data rate gets limited when 2M phy is used?

Best regards
Torbjørn