Sending data bigger than 20 byte with ble

[Dong Pham]

Hi Im working on the project which relates to sending data through ble. I use nrf51822 Evaluation kit and the data is from uart. How do I send data greater than 20 bytes. No matter how i change the parameters from which relate to that 20, it is still limited at 20 bytes. Let say i want to transfer a 2kb file through ble. So how do i fix my code? main.c ble_nus.c app_uart_fifo_mod.c

Thank you very much

[Nguyen Hoan Hoang]

see examples on this blog site http://embeddedsoftdev.blogspot.ca/p/ehal-nrf51.html

[Ulrich Myhre]

You will have to disassemble your data into segments of 20 bytes or less. The data is guaranteed to arrive in the same order it is sent. The receiver will have to store the received data and periodically flush it to e.g. flash memory or a transport like SPI/UART.

There are multiple ways of solving this on both sides. It can be done with notifications alone, or with writes to a characteristic. See the DFU example for some inspiration on how to send larger files like softdevices.

[Victor]

Can you please elaborate? There are no examples directly in the post, where to look for them? The only ones I found in your Github were for iOS.

[Victor]

Can you please add a reference to the mentioned example? I'm struggling to find a ready solution to data chunking/reassembling.

[Nguyen Hoan Hoang]

There are links to the github repo. It is multi-platform code supporting NXP, Nordic, Freescale, TI. There are shared generic source for all and specific for each MCU.