Datasheet

Central BLEUART

This example show you how to use Feather nRF52 as a Central to talk to other Bluefruit (nRF52 or nRF51) peripherals

exposing the bleuart (AKA 'NUS') service.

Client Services

Since the Central role accesses the GATT server on the peripheral, we first need to declare a client bleuart instance

using the BLEClientUart helper class. We can also conveniently read Device Information if BLEClientDis is also used.

Before we can configure client services, Bluefruit.begin() must be called with at least 1 for the number of concurrent

connections supported in central mode. Since we won't be running the nRF52 as a peripheral in this instance, we will

set the peripheral count to 0:

Afterward this, the client service(s) must be initialized by calling their begin() function, and you can setup any callbacks

that you wish to use from the helper class:

Scanner

Let's start the advertising scanner to find a peripheral.

We'll hook up the scan result callback with setRxCallback().

Whenever advertising data is found by the scanner, it will be passed to this callback handler, and we can examine the

advertising data there, and only connect to peripheral(s) that advertise the bleuart service.

Note: If the peripheral has multiple services and bleuart is not included in the UUID list in the advertising packet, you

could optionally use another check such as matching the MAC address, name checking, using "another service", etc.

Once we find a peripheral that we wish to communicate with, call Bluefruit.Central.connect() to establish connection with

it:

BLEClientDis clientDis;

BLEClientUart clientUart;

// Initialize Bluefruit with maximum connections as Peripheral = 0, Central = 1

Bluefruit.begin(0, 1);

// Configure DIS client

clientDis.begin();

// Init BLE Central Uart Serivce

clientUart.begin();

clientUart.setRxCallback(bleuart_rx_callback);