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G.FIT User Guide and Specification, Rev 2.0_Alpha.14
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4.1.5.2.1
No display connected to peripheral
If G.FIT moves to state FINISHED while there is no display connected and the BLE FTMS peripheral is still
advertising (the time spend in state IN USE was less than the InUseAdvertisingTimeout), the
InUseAdvertisingTimeout will reset and the peripheral will continue to advertise for the timeout duration.
4.1.5.2.2
Display connected
If a display is paired to G.FIT when moving to state FINISHED, the BLE FTMS peripheral will not advertise in
state FINISHED.
4.2
Pairing heart rate monitors
G.FIT provides two methods of connecting to heart rate monitors to best fit the required use case:
•
Proximity pairing allows the user to pair a heart rate monitor by physically moving the heart rate
monitor to within the ‘pairing zone’ of the G.FIT module.
•
Channel ID based pairing gives the application the flexibility to select which heart rate monitor to
pair with; allowing the user to manually select the desired heart rate monitor by scrolling through all
available heart rate monitors seen by G.FIT.
4.2.1
Proximity pairing
G.FIT will pair with a heart rate monitor automatically based on the proximity to the G.FIT module. In order
to successfully pair with a heart rate monitor, the received signal strength received from the heart rate
monitor must maintain a specified signal strength during each phase of the connection process. There are
three phases in the connection process: searching, pairing, and tracking. See Figure 4-2 for typical zone
sizes.
Searching:
This phase of the connection process searches for possible heart rate monitor to connect to. It
has the strictest RSSI threshold so that a heart rate monito r must be brought in close proximity to the G.FIT
module. Once a heart rate monitor is detected in the searching phase it then advances to the Pairing phase.
Pairing:
This phase of the connection process ensures that the heart rate monitor found in the sea rching
phase maintains a close proximity to the G.FIT module. This helps prevent accidental connections to other
heart rate monitor. This threshold is less strict than searching but should be defined so that the user must
keep the heart rate monitor in the pairing zone during the initial connection process. Once G.FIT receives the
sufficient number or packets from the heart rate monitor within the defined signal strength, a connection is
established and the heart rate monitor advances to the tracking phase.
Tracking:
The tracking phase is used to maintain a connection to the heart rate monitor while the user is
using the fitness equipment.