NRF connect send >20 bytes error

[Chocol8]

Hello Nordic community,

First of all would like to say that I am aware that BLE protocol allows to send only up to 20 bytes size packets. Moreover, I understand that I should be spliting it into several packets in order to send more than 20.

I have tried both pc10028 and my custom board using nrf51822. I am using s110_7_2, SDK 6, modified ble_app_uart example, NRF connect installed in a tablet.

My question is: who is not able to handle this >20bytes packet? Is it the app or the peripheral (pca10028)? Am I able to detect this kind of error with peripheral and to reply back to the application that it was sent a too large packet?

This is how i proceed the test: I've connected app to my board. Then I allowed notifications from app side. |1| Sent <20bytes (111111) packet. It was succesful. Received a reply from the board.|2| Sent >20bytes (22222222222...) packet. Have not received a reply from board, in the application logg I do not see that the packet would be sent out. Master disconnected from peripheral

Application logg:

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Thank you for your time, guys.

[shibshab]

Your request is split into [multiple] "Prepare Write Requsets", these needs to be followed by an "Execute Write Request", but from your log it does not seem like this happens. There might be a bug in nRF Connect if it never sends this Execute Write Request after sending the Prepare Write Request.

who is not able to handle this >20bytes packet? Is it the app or the peripheral (pca10028)?

No >20 byte package is sent. It is split into [multiple] Prepare Write requests.

Am I able to detect this kind of error with peripheral and to reply back to the application that it was sent a too large packet?

No valid BLE implementation will never send a packet which is too long according to spec.

[Chocol8]

@shibshab Thank you, this is a very clear answer.