NRF UART SERVICE long data to send

RE: NRF UART SERVICE long data to send

FormerMember — Mon, 10 Oct 2016 13:39:33 GMT

Yes, it's that one!

RE: NRF UART SERVICE long data to send

jean.oriano — Mon, 10 Oct 2016 13:36:38 GMT

is this ? github.com/.../Android-nRF-Toolbox

RE: NRF UART SERVICE long data to send

FormerMember — Mon, 10 Oct 2016 12:31:54 GMT

Try to use the code from the UART application in the nRFToolbox instead, because the standalone nRF UART app is quite old..

RE: NRF UART SERVICE long data to send

jean.oriano — Mon, 10 Oct 2016 11:57:03 GMT

no, i use the NrfUart android application

RE: NRF UART SERVICE long data to send

FormerMember — Mon, 10 Oct 2016 11:43:34 GMT

jean.orinao: For sending data over uart, do you use the code for the UART application in the nRFToolbox?

RE: NRF UART SERVICE long data to send

RK — Wed, 05 Oct 2016 14:02:13 GMT

it's in the header file

#define BLE_NUS_MAX_DATA_LEN (GATT_MTU_SIZE_DEFAULT - 3) /**< Maximum length of data (in bytes) that can be transmitted to the peer by the Nordic UART service module

and with this definition

#define GATT_MTU_SIZE_DEFAULT 23

you can see that 20 bytes is the max you can send with ble_nus_string_send(). If you want to send more you have to send multiple notifications one after another as the previous one finishes.

There is no max length in the hvx function because it's already in the BTLE spec that notifications and indications have max length MTU-3

don't know anything about java.

RE: NRF UART SERVICE long data to send

jean.oriano — Wed, 05 Oct 2016 13:31:50 GMT

If i want to send 40bytes over uart service with my nrf51, i use this function :

uint32_t ble_nus_string_send ( ble_nus_t * p_nus, uint8_t * p_string, uint16_t length )

link of function in infocenter : infocenter.nordicsemi.com/index.jsp

no detail for the length of data ? i can send 500 bytes and this function cut in 20bytes packages my data ?

I enter in this function and look at hvx_params.p_len : infocenter.nordicsemi.com/index.jsp

And nothing about max length.

And about java function to send data. any doc ? infocenter dont anwser me about java doc for ble and nordic uart service.

I think about this function mService.writeRXCharacteristic(data_in_byte_not_more_than_20_bytes) to send data over ble. if i want to send more than 20 bytes, i thougth it can be that :

            while(i < mess_encaps.length) {
                for (int j = 0; j < 20; j++) {
                    envoie[j] = mess_encaps[i];
                    i++;
                }
                mService.writeRXCharacteristic(envoie);
            }

but didnt work.

RE: NRF UART SERVICE long data to send

RK — Wed, 05 Oct 2016 10:49:43 GMT

packets have a guarantee of arrival and a guarantee of arrival in the order they were sent. So if you send 1 2 3 4 5 you will receive 1 2 3 4 5 and if anything goes wrong, the connection will be terminated.

RE: NRF UART SERVICE long data to send

jean.oriano — Wed, 05 Oct 2016 10:03:05 GMT

I know its impossible to send more than 20 bytes per package. I want to say, my data is longer than 20 bytes. i want to send it to my smartphone but i need more than 1 package.

Its that i dont succeed to do.

if i send 5 package for my data : 1 2 3 4 5

with the BLE protocol, i dont lose package but is the package come in the same order ? 1 2 3 4 5 ?

or is it possible that a package come before an other ?

RE: NRF UART SERVICE long data to send

FormerMember — Wed, 05 Oct 2016 09:45:52 GMT

It is (currently) not possible to transmit more than 20 bytes of data per package between a nRF51/52 and Android.

When transferring data using notifications, it is not necessary to get a confirmation in the application layer that the notification was received. BLE is a reliable protocol that doesn't accept packet loss, and all packets are ACK'ed in the link layer. If a packet is not ACK'ed, it is re-transmitted until success or until timeout.