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]

Hi,

Is it the BLE data rate you want to increase? What are you connecting against? A smartphone?

You can lower the connection interval by changing the MIN_CONN_INTERVAL and MAX_CONN_INTERVAL values. Try setting it to e.g :

#define MIN_CONN_INTERVAL               MSEC_TO_UNITS(7.5, UNIT_1_25_MS) 
#define MAX_CONN_INTERVAL               MSEC_TO_UNITS(20, UNIT_1_25_MS) 

There are also several other things you can do to increase the data rate. Such as increasing the ATT MTU size, enable Data length extension (DLE) and enable Connection event length extension.

[Ferhat B]

Does uart interrupt works while sending pack. I read Soft Device dedicated to 20 bytes pack, Can i increase it.

I tried MSEC_TO_UNITS(7.5, UNIT_1_25_MS) but didnt make sense. Its an ECG Graph and for this step we use ipad

[Ferhat B]

I tried to fill 15 packet in other mcu. (every pack has 20 bytes) Thans send one by one every pack, squentaly. (Means 15 times 20 byte sequental) Result better.

But i read Soft Device send 6 packs one time, so i understand problem is not ble waiting.

[Ferhat B]

Is it acceptable to send 158 byte in pheripheral usage.

[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