How to increase Data Rate

[Ferhat B]

Hi

We use ble_app_uart_pca10040 app. We have our own board has microcontroller and send data over uart to ble module (bmd350) There is Nrf52832. I want to send 32byte pack and 500pack in sec. Im very far to achive that.

Ferhat

[Sigurd]

Are you using SDK 13? What ATT MTU size, and if you can enable DLE depends on what iPad version and what iOS version your iPad has.

If you enable DEBUG logging (#define NRF_LOG_DEFAULT_LEVEL 4 in sdk_config.h), you should be able to see the parameters that is negotiated between the central and peripheral.

[Ferhat B]

Yes use SDK 13
BLE_GATT_ATT_MTU_DEFAULT 23
ble_hrs_heart_rate_measurement_send >> 20 bytes as pack length

[Ferhat B]

Do you mean 64 in below as ATT MTU
err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, 64);

[Sigurd]

Yes, the BLE_GATT_ATT_MTU_DEFAULT is 23, but if you use the ble_app_uart example in sdk 13, you have the m_ble_nus_max_data_len that is updated after ATT MTU exchange with the central. In the function gatt_init() in main.c we are trying to increase the ATT MTU to 64.

[Ferhat B]

Does the soft device send 6 pack together.
How much time ble sending (sd_ble_gatts_hvx) stops uart hanling.
I think the problem is uart waiting while ble sending.

About ATT MTU what is the maximum value, how much i can make "m_ble_nus_max_data_len" May i send 158bytes in one pack. In soft device document is see for client Att MTU 23 and 7.5ms