The Settings module configures Bluetooth LE parameters and reports diagnostic information about the board. Functions communicating with this module are defined in the settings.h header file.

Battery State

The battery data provided by the Settings module reports both charge percetange and voltage, encapsulated by the MblMwBatteryState struct. Unlike the battery gatt servive, this battery data can be utilized with MetaWear features such as the logger.

#include "metawear/core/datasignal.h"
#include "metawear/core/settings.h"
#include "metawear/core/types.h"

void battery_stream(MblMwMetaWearBoard* board) {
    static auto state_handler = [](const MblMwData* data) -> void {
        auto state = (MblMwBatteryState*) data->value;
        printf("{voltage: %dmV, charge: %d}\n", state->voltage, state->charge);

    auto battery_signal = mbl_mw_settings_get_battery_state_data_signal(board);
    mbl_mw_datasignal_subscribe(battery_signal, state_handler);


Handling Disconnects

The disconnect event is a type of MblMwEvent that is fired when the Bluetooth connection is terminated.

#include "metawear/core/event.h"
#include "metawear/core/settings.h"

#include "metawear/sensor/accelerometer.h"

void handle_disconnect(MblMwMetaWearBoard* board) {
    static auto cmds_recorded = [](void) -> void {
        printf("commands recorded\n");

    auto dc_event = mbl_mw_settings_get_disconnect_event(board);
    // stop the accelerometer when connection is lost
    mbl_mw_event_end_record(dc_event, cmds_recorded);

Advertising Parameters

Advertising parameters control how the Bluetooth radio sends its advertising data. You can modify the device name, timeout, tx power, and scan response. If you have set an timeout, you can manually begin another advertisement cycle by calling mbl_mw_settings_start_advertising.

#include "metawear/core/settings.h"

void modify_ad_params(MblMwMetaWearBoard* board) {
    // change the device name to 'metaware'
    const uint8_t* name = "metaware";
    mbl_mw_settings_set_device_name(board, name, 8);

Connection Parameters

Connection parameters control how BTLE devices communicate with each other. Modifying the connection parameters are all handled at the same time by calling mbl_mw_settings_set_connection_parameters. A more detailed explanation of about BTLE connection parameters can be found on this post from the Nordic Developer Zone forums.

#include "metawear/core/settings.h"

void modify_conn_params(MblMwMetaWearBoard* board) {
    mbl_mw_settings_set_connection_parameters(board, 10.f, 1024.f, 0, 6000);