How to increase the data rate

[Ryon_pan]

Hi, I want to send 9000bytes one sencond.But when I send these bytes it will return error code is 19.

I had increased the ATT MTU to 274 with the function of nrf_ble_gatt_att_mtu_periph_set(&m_gatt, 247);     I use SDK15.0

anyboby konw why? 

[awneil]

Ryon_pan said:

it will return error code is 19

What will ?

Have you looked-up the meaning of that code?

[Ryon_pan]

The meaning of that code is not enough resources for operation.But I dont know what the meaning of it

[awneil]

Have you tried stepping through the code to see what, exactly, causes it?

[Bjørn Kvaale]

Ryon_panWhich example are you currently running? Which SDK version are you using? I would recommend taking a look at the ATT MTU throughput example from SDK v15.2, as well as these links: link 1, link 2 & link 3. This link should also be helpful.

[Ryon_pan]

Thank you for your reply.I use the version of SDK is 15.0.I just want to know if I want to  send more data one time.And how to do that.

I will take a look at these links which was recommend by you.

[Bjørn Kvaale]

The max ATT MTU size you can use is 247. See this documentation: "ATT_MTU size: The default Maximum Transmission Unit (MTU) is 23 bytes. When increasing this value, longer ATT payloads can be achieved, increasing ATT throughput."

You tried to increase the att mtu size even higher, which is not possible.