4 System overview
Doc. ID 4414_003 v1.2
Page 19
4.1 Remote control
The flexibility of the remote control allows you to experiment with your own firmware and functionality. After
pairing, the trackpad, accelerometer, and free-space navigation can be enabled and calibrated.
Important:
Gyroscope calibration is performed automatically the first time the firmware is run on the
hardware.
4.1.1 Pairing
When the remote control is turned on, it will attempt to connect to a bonded
Bluetooth
®
low energy
compatible master if bonds are available. Otherwise it will be in pairing mode and will wait for connection
from host.
The Smart Remote 3 features the HID-over-GATT profile and can connect to any
Bluetooth
®
low energy host
system supporting this profile. The HID-over-GATT profile is a direct mapping from the USB HID standard. In
addition to controlling how the HID data is transferred through the wireless link, the profile requires the use
of
Bluetooth
®
device security. Security and data encryption are handled by the
Bluetooth
®
Security Manager,
which is a
Bluetooth
®
protocol layer handled by nRF51822. On the master side of the
Bluetooth
®
link, the
Security Manager is handled in the
Bluetooth
®
driver stack.
If no bonds are stored in flash, the remote control will start to advertise to Smart Ready devices for pairing
when it is turned on. When Smart Remote 3 is in this advertising state, the
Bluetooth
®
host platform should
be instructed to start scanning for and then to connect to it. During this initial connection an encrypted link is
configured by nRF51822 and the host transmits HID commands to the Smart Remote 3 according to the HID-
over-GATT profile.
The remote control will stay in bond mode for 180 seconds waiting for a
Bluetooth
®
connection. If no
connection is established, the remote control will enter deep sleep. Bonding mode will be resumed upon user
activity.
Although the specifics of the pairing process may differ between platforms, the main steps remain the same.
1.
Scan for Smart Remote 3.
2.
Connect to Smart Remote 3.
3.
Bond/pair with Smart Remote 3.
Read more about
Bluetooth
®
low energy and HID- over-GATT at
developer.bluetooth.org
.
4.1.2 Trackpad
The trackpad has five-point multi-touch functionality and advanced gesture recognition, making it a versatile
interface device for the remote control.
The trackpad is a
Synaptics
®
ClickPad. It is identified as a standard mouse by your computer and does not
require any special software application to work.
Basic use
To use the trackpad, place one of your fingers on the surface of the pad as shown in
Figure 3: One-finger
movement
on page 20. As you move your finger along the trackpad surface, you should see the mouse
cursor on your computer screen moving according to the movement of your finger.
