Extend the MTU with SDK 15.2

[oalt]

Hi!

Is there an example to extend the Bluetooth MTU size to more than 20 bytes together with SDK 15.2?

I found only examples with older versions.

Thank you in advance.

Best regards

Oliver

[oalt]

Hi,

my central is a PC with a CSR8510 A10 USB BLE dongle. I have written a test program using node.js and the noble BLE library.

I set the desired MTU in the SDK config file ( NRF_SDH_BLE_GATT_MAX_MTU_SIZE).

What is not clear for me: From which side the server_rx_mtu value comes from? Is it the peripherial device or the central device?

[Edvin]

So did you try the unmodified ble_app_uart example? The reason that I keep asking for this is that if you test this, then you can figure out whether it is your nRF application or PC application that hasn't set the correct MTU.

If your nRF is the peripheral, then the m_rx_mtu is the PC. 

How does your project use NRF_SDH_BLE_GATT_MAX_MTU_SIZE? It is a define, but it doesn't matter if your application doesn't use this define anywhere in the application.

What does your gatt_init() look like? Do you use the NRF_SDH_BLE_GATT_MAX_MTU_SIZE there?

BR,

Edvin

[oalt]

You are right. I tried to connect using the nRF connect app on an Android phone and now the MTU is extended. So it seems to be a problem with my test environment. Thank you for the support.

I will close the ticket.