Settings¶
You can control several BLE settings on the MetaWear board, encapsulated with the MBLSettings object.
Radio Power¶
The radio transmit power is also exposed through a property. Setting a smaller (lower dBm) value will result in a weaker radio signal, default is MBLTransmitPower0dBm
device.settings?.transmitPower = .power0dBm
Circular Buffer Log¶
Choose what happens if the internal log fills up. If circularBufferLog is YES then the oldest log entries will be deleted to make room for now entries, if NO then new entries will be discared. Defaults to NO.
device.settings?.circularBufferLog = false
Scan Response¶
You can modify the BLE Ad Packet to advertise application specific data, this is done by setting a raw byte array which will be sent in the BLE scan response. One example is to have the MetaWear behave as a URI Beacon:
// Make it advertise http://www.mbientlab.com
let rawuri = Data(bytes: [0x03, 0x03, 0xD8, 0xFE, 0x10, 0x16, 0xD8, 0xFE, 0x00, 0x12, 0x00, 0x6D, 0x62, 0x69, 0x65, 0x6E, 0x74, 0x6C, 0x61, 0x62, 0x00])
device.settings?.scanResponse = rawuri
Advertising Settings¶
You can change the advertising interval and advertising timeout if you require advanced power saving features. This should be carefully considered, because it affects the time to discovery and connect performance, and also battery life.
This is a startAdvertisement method which can be explicitly use to start advertisement after an advertising timeout has occured. You can hook this call up to any MBLEvent if you need advanced ways to start advertising. Note a button press it already hard coded to always trigger advertising, which should cover most cases.
device.settings?.advertisingInterval = 417.5; // Default value
device.settings?.advertisingTimeout = 0; // Default value - always advertise
device.settings?.startAdvertisementAsync()
Pairing/Bonding¶
In a few special cases, you may need to enable of Bluetooth level bonding. This is still in development, so not everything is exposed. To begin pairing simply call:
device.settings?.initiatePairingAsync()
To fully destroy the bond, you need to first call deleteAllBonds then disconnect. Second, “Forget” the device in the iOS Settings APP under Bluetooth.
device.settings?.deleteAllBondsAsync()
Disconnect Event¶
Event representing a BLE disconnection event. Note this doesn’t make sense to stream, but it’s likely that programCommandsToRunOnEventAsync will have utility.
// Flash red LED twice on disconnect
device.settings?.disconnectEvent?.programCommandsToRunOnEventAsync {
device.led?.flashColorAsync(.red, withIntensity: 1.0, numberOfFlashes: 2)
}
MAC Address¶
Get the MAC address of the MetaWear.
device.settings?.macAddress?.readAsync().success { mac in
print(mac)
}
Connection Parameters¶
Bluetooth LE connection parameters control how the ble devices communicate with each other. Configuring these parameters is done with the via properties on the MBLSettings object. A more detailed explanation on connection parameters can be found on the Nordic Developer Zone:
// change min conn interval to 10ms,
// max conn interval to 1024ms
device.settings?.minimumConnectionInterval = 10
device.settings?.maximumConnectionInterval = 1024
device.settings?.applyConnectionParametersAsync()
Power Status¶
Firmware v1.3.2 exposes battery charging and power status notifications which provides information on when the battery is charging / not charging and when a power source is attached / removed, respectively. The data is interpreted as a byte or boolean with 1 (true) signifying battery charging / power source attached, and 0 (false) meaning battery not charging / power source removed. Not all boards support this feature and a null pointer will be returned if powerStatus or chargerStatus is called on an unsupported board.
device.settings?.chargerStatus?.startNotificationsAsync(handler: { (obj, error) in
print(String(describing: obj))
})
device.settings?.powerStatus?.startNotificationsAsync(handler: { (obj, error) in
print(String(describing: obj))
})