How to send the data from central to peripheral

[chandana k v]

Hi,

I am using the nrf51422 controller and other controller which contains Bluetooth .The nrf51422 Bluetooth is central and other controller Bluetooth is peripheral.I am using SDK 12.3 in which i am using ble_central\ble_app_blinky for nrf51 422 Bluetooth .I have tried this example program so the nrf51422 bluetooth is paired with other controller bluetooth by changing the device name in example program instead of "nordic_blinky" to my device name.So as of now it is paired now i need to send the data from the nrf51422 to peripheral  bluetooth so in this example program the data  send function is not there .so i have included the send function in this example program here the problem is data is not sending to peripheral.can you tell me what is the problem.

I thought of using ble_central\ble_app_uart program .In this program the Bluetooth is connecting based on the uuid of the device.Here i don't know what  is the uuid of the peripheral  Bluetooth

so i have tried this  example  ble_central\ble_app_blinky.Soplz can you tell me how to send the data.

void send_ble_data(uint8_t * p_data, uint16_t length)
{
static uint8_t data_array[BLE_NUS_MAX_DATA_LEN];
memcpy(data_array, p_data, length);
ble_nus_c_string_send(&m_ble_nus_c, data_array, length);
NRF_LOG_INFO("sent.\r\n");
}

[Vidar Berg]

Hi,

You need to include the Nordic UART client/server on both sides if you're going to use ble_nus_c_string_send() function, and then it would be better to use ble_app_uart as a starting point instead of blinky. You can use ble_lbs_led_status_send() to send data with the blinky example. 

[chandana k v]

Can you plz tell me how to send the data through ble_lbs_led_status_send()  function. Bcoz in this function the led status  is there .Then my question is how do i send the data through this function.

I can't use Nordic UART client/server service bcoz the server side i am using other bluetooth controller i don't know how to connect the bluetooth through the NUS service. Can you plz tell me how to send the data

[awneil]

chandana k v said:

I can't use Nordic UART client/server service bcoz the server side i am using other bluetooth controller

That's not true.

The whole point of standards like BLE is that they are not bound to specific hardware.

The whole point of GATT is that any compliant BLE device can discover the Services & Characteristics on any other compliant BLE device - irrespective of whether they are from different manufacturers.

 

https://devzone.nordicsemi.com/f/nordic-q-a/51786/how-to-connect-from-one-bluetooth-to-other-bluetooth-devices/208161#208161

https://devzone.nordicsemi.com/f/nordic-q-a/52165/not-able-to-connect-the-bluetooth-to-other-device

The NUS documentation describes the Service & the Characteristics it uses:

https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v15.3.0/ble_sdk_app_nus_eval.html

[chandana k v]

Thanks for the reply.

But here in the NUS service we need to mention the base UUID, service UUID,TX characterstic UUID ,Rx characterstic UUId. I don't know the UUID of the other Bluetooth.i searched in the google but i didn't get it.

Is there any method to transfer the data .I am not getting the idea plz help me

[Vidar Berg]

You can use the nRF connect app android or iOS to inspect the advertisement packet from your peripheral. For instance, check if it includes any UUIDs that you can filter on. When you have done this you can configure the Scanning Module to filter on one or more of its parameters. It is possible to only filter on the device name for instance.

However, this will only let you find the correct device to connect to, you still to implement a GATT client to access the various characteristics on your server. You may use UART client as a starting point and adapt it to the services you have on the peripheral.  

[chandana k v]

Thanks for the reply.I will try