Send a string to peripheral with ble_app_multilink_central

[BMG]

Hello,

I have two boards of nRF52840, one being central and the other is peripheral. On the central I've put the code from ble_app_multilink_central and on the peripheral ble_app_blinky.

I've managed to connect each other, but I'm not able to send a string from central to peripheral or viceversa.

I've read many posts regarding this problem, and I concluded that I have to use the code from ble_app_uart_c as the central, and ble_app_uart as the peripheral.

I tried this, but in the ble_app_uart_c, at ble_stack_init() function I get a reset and the led is blinking all the time. I've also tried with multiple versions of SDK and it's the same.

So, returning at the ble_app_multilink_central, what functions should be used to be able to send a message? I've also read posts about combining the code from ble_app_uart_c and ble_app_multilink_central, but nothing helped me.

Please help me.

Thank you!

[Simon]

Before answering your questions I would recommend you to go through some Nordic BLE tutorials, in order to get a better understanding of how to create BLE applications with the nRF5 SDK and Nordic chips. Then you will understand how it works on a deeper level and how to send a string. Check out these tutorials:

• https://devzone.nordicsemi.com/nordic/short-range-guides/b/bluetooth-low-energy/posts/ble-advertising-a-beginners-tutorial
• https://devzone.nordicsemi.com/nordic/short-range-guides/b/bluetooth-low-energy/posts/ble-services-a-beginners-tutorial
• https://devzone.nordicsemi.com/nordic/short-range-guides/b/bluetooth-low-energy/posts/ble-characteristics-a-beginners-tutorial

Back to your problem. I would recommend you to use the ble_app_uart_c and the ble_app_uart as mentioned. However, it is strange that it is failing, it should work out-of-the-box. Could you try the following:

• Download a clean version of nRF5 SDK 16: https://www.nordicsemi.com/Software-and-tools/Software/nRF5-SDK/Download
• Install SEGGER Embedded Studio if you haven't already installed it: https://www.youtube.com/watch?v=YZouRE_Ol8g&list=PLx_tBuQ_KSqGHmzdEL2GWEOeix-S5rgTV&index=1
• Open nRF5_SDK_16.0.0_98a08e2\examples\ble_peripheral\ble_app_uart\pca10056\s140\ses\ble_app_uart_pca10056_s140.emProject
• Connect your nRF52840 DK and turn it on
• In SEGGER, click on Build→Build and Run
• Install nRF Connect App on your mobile phone (https://play.google.com/store/apps/details?id=no.nordicsemi.android.mcp&hl=no, https://apps.apple.com/us/app/nrf-connect/id1054362403)
• Open the app, click on "SCANNER" and check if can see the device "Nordic_UART"
  • If you do this, then you know that the application ble_app_uart is working properly

Best regards,

Simon