ANT+ Garmin G.FIT User manual

G.FIT
User Guide and Specification

Page 2 of 117 G.FIT User Guide and Specification, Rev 2.0_Alpha.14
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Revision History
Revision
Effective Date
Description
1.0
June 2017
Initial Customer Sample Release.
1.1
September 2017
Customer Sampling Update
1.2
September 2017
Production Release
2.0
May 2018
Update serial interface with messaging for G.FIT 4.0.0
•Add controllable features
•Extension to custom events
•Consistent resistance resolution
•Product information configuration outside of FE metrics, with
customizable device/manufacturer strings
•Add configuration option to disable HR pairing
•Add rower instantaneous pace as a transmitted field over BLE
Additions to GFIT_SetDeviceID (0xE3) to include information on how the
channel ID is constructed from the device ID
2.0_Alpha.05
May 2018
Format cleanup, G.FIT template. Spelling and phrasing changes in progress.
2.0_alpha.06
May 2018
Added section 4.7 –G.FIT custom service.
Reworking spin down command payload table and descriptions
Fixed all references.
2.0._alpha.07
May 2018
Fixed incorrect message sizes, missing/incorrect invalid values.
Updated section 4.6 –Custom Events.
Added section 6.1- ANT+ Manufacturer specific pages
Add clearer resistance specification and calcs.
2.0_alpha.10
July 2018
Merge in changes from Tom and Mark.
2.0_alpha.11
November 2018
Updating company branding
2.0_alpha.13
June 2019
Updated HR Serial Message Format
2.0_alpha.14
June2019
Added more parameters to section 7.3.2 –
gfit_fep_set_channel_configuration
Added interaction details for new parameters and gfit_hrp_set_pairing_mode
Added section 7.3.23 –gfit_fep_set_developer_options (0xDB)
Added section 7.5.8 –gfit_event_ble_peripheral (0xBA)

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Table of Contents
1Support ...................................................................................................................................................................... 11
1.1 G.FIT technical references .................................................................................................. 11
2Use case ..................................................................................................................................................................... 13
3Development kit contents ........................................................................................................................................ 15
3.1 G.FIT libraries ................................................................................................................... 15
3.2 G.FIT software development kit ........................................................................................... 15
3.2.1 Example SoC application (demo_gfit) ....................................................................... 16
3.2.2 Fitness equipment console simulator PC application ................................................... 16
3.2.3 Reference CIQ application ...................................................................................... 16
3.2.4 Reference iOS application ....................................................................................... 16
3.2.5 SimulANT+ ........................................................................................................... 16
4G.FIT operation ......................................................................................................................................................... 17
4.1 Fitness equipment (FE) states ............................................................................................. 17
4.1.1 G.FIT CONFIGURATION (OFF) ................................................................................. 18
4.1.2 OFF ..................................................................................................................... 18
4.1.3 READY ................................................................................................................. 18
4.1.4 IN USE ................................................................................................................. 18
4.1.5 FINISHED (PAUSED) .............................................................................................. 19
4.2 Pairing heart rate monitors ................................................................................................. 20
4.2.1 Proximity pairing ................................................................................................... 20
4.2.2 Channel ID based pairing ....................................................................................... 21
4.3 G.FIT configuration ............................................................................................................ 21
4.4 Event handling .................................................................................................................. 22
4.4.1 Enabling events ..................................................................................................... 23
4.4.2 Event responses .................................................................................................... 23
4.5 Custom events ................................................................................................................... 26
5Connecting to G.FIT over BLE .................................................................................................................................. 27
5.1 Interpreting resistance ....................................................................................................... 28
5.2 G.FIT custom service .......................................................................................................... 30
5.2.1 Custom control point characteristic .......................................................................... 30
5.2.2 Custom data characteristic ..................................................................................... 31
5.2.3 Procedures ........................................................................................................... 31
5.2.4 Setting the user and/or bicycle weight ..................................................................... 31
5.2.5 Setting manufacturer specific data .......................................................................... 33
5.2.6 Notification of updated manufacturer specific value ................................................... 34
6Connecting to G.FIT over ANT+ FE-C...................................................................................................................... 36
6.1 Dual frequency FE-C........................................................................................................... 36
6.2 ANT+ manufacturer specific pages ....................................................................................... 36

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6.2.1 Receiving custom events ........................................................................................ 36
6.2.2 Sending custom events .......................................................................................... 37
6.3 Using SimulANT+ to view transmitted data ........................................................................... 37
6.4 Tracking FE-C channel with CIQ application .......................................................................... 38
6.4.1 Installing CIQ application on a compatible Garmin watch ........................................... 38
6.4.2 Opening the application ......................................................................................... 38
6.4.3 Connecting to the G.FIT ANT+ FE -C channel............................................................. 38
6.4.4 Viewing live workout data....................................................................................... 38
6.4.5 Saving user’s workout session ................................................................................. 38
6.4.6 Viewing workout data ............................................................................................ 38
6.5 FE-C Control Messages ....................................................................................................... 38
7Serial interface .......................................................................................................................................................... 39
7.1 Using extended serial messages .......................................................................................... 39
7.1.1 Commands (0xE2) ................................................................................................. 40
7.1.2 Requests (0xE1) .................................................................................................... 40
7.1.3 Responses/events (0xE0) ....................................................................................... 41
7.2 G.FIT response codes ......................................................................................................... 41
7.3 Commands (0xE2) .............................................................................................................. 44
7.3.1 gfit_fep_set_state_ (0xD0) ..................................................................................... 44
7.3.2 gfit_fep_set_channel_configuration (0xD1) ............................................................... 45
7.3.3 gfit_hrp_set_pairing_mode (0xD2) .......................................................................... 47
7.3.4 gfit_hrp_set_inuse_scan_timeout (0xD3) .................................................................. 48
7.3.5 gfit_hrp_set_pairing_proximity (0xD5) ..................................................................... 49
7.3.6 gfit_hrp_pair_to_device (0xD6) ............................................................................... 50
7.3.7 gfit_hrp_disconnect_device (0xD7) .......................................................................... 52
7.3.8 gfit_enter_bootloader (0xD8) .................................................................................. 53
7.3.9 gfit_fep_set_inuse_adv_timeout (0xD9) ................................................................... 54
7.3.10 gfit_fep_set_equipment_type (0xE0) ................................................................... 55
7.3.11 gfit_fep_set_XX_data (0xE1) ............................................................................... 57
7.3.12 gfit_hrp_set_heart_rate (0xE2) ........................................................................... 66
7.3.13 gfit_fep_set_device_id (0xE3) ............................................................................. 67
7.3.14 fe_command_product_info (0xE4) ....................................................................... 69
7.3.15 gfit_fep_send_command_update (0xE5) ............................................................... 71
7.3.16 fe_command_status_update (0xE6) ..................................................................... 72
7.3.17 gfit_fep_abort_pending_commands (0xE7) ........................................................... 75
7.3.18 gfit_fep_set_max_resistance (0xE8) .................................................................... 76
7.3.19 gfit_fep_spin_down_ (0xE9) ............................................................................... 77
7.3.20 gfit_fep_send_custom_event (0xB0) .................................................................... 85
7.3.21 gfit_fep_send_manufacturer_specific_page (0xB3) ................................................ 86
7.3.22 gfit_fep_set_transmission_pattern (0xDA) ............................................................ 87

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7.3.23 gfit_fep_set_developer_options (0xDB) ................................................................ 88
7.4 Requests (0xE1) ................................................................................................................ 89
7.4.1 gfit_get_version_string (0xC0) ................................................................................ 89
7.5 Events (0xE0) .................................................................................................................... 91
7.5.1 gfit_event_receive_heart_rate_ (0xB2) .................................................................... 91
7.5.2 Session command event (0xB4) ............................................................................... 95
7.5.3 gfit_event_set_target_ (0xB5) ................................................................................ 96
7.5.4 gfit_event_set_simulation_parameters (0xB6) ........................................................... 97
7.5.5 gfit_event_set_user_data (0xB7) ............................................................................. 98
7.5.6 Spin down Calibration Event (0xB8) ............................... Error! Bookmark not defined.
7.5.7 gfit_event_entering_bootloader (0xB9) ...................................................................100
7.5.8 gfit_event_ble_peripheral (0xBA) ...........................................................................100
7.5.9 gfit_event_custom (0xB1)......................................................................................101
7.6 Other ANT commands ........................................................................................................102
7.6.1 Read ANT ID ........................................................................................................102
7.6.2 RSSI calibration offset ..........................................................................................103
Appendix A - G.FIT SoC library........................................................................................................................................ 104
A.1 Compiling the demo application ..........................................................................................104
A.1.1 Library license key ................................................................................................104
A.1.2 Compiler compatibility ...........................................................................................105
Appendix B - Fitness equipment console simulator...................................................................................................... 106
B.1 Introduction .....................................................................................................................106
B.2 Installing ANT USB interface board driver ............................................................................106
B.3 Basic operation .................................................................................................................108
B.3.1 Initial G.FIT setup ................................................................................................108
B.3.2 Turning on the simulated console ...........................................................................110
B.3.3 Pairing a heart rate monitor...................................................................................110
B.3.4 Successfully paired heart rate monitor ....................................................................111
B.3.5 Disconnecting a paired heart rate monitor ...............................................................111
B.3.6 Starting a workout/session ....................................................................................111
B.3.7 Pausing/resuming a session ...................................................................................112
B.3.8 Ending a session ..................................................................................................112
B.3.9 Turning off the simulated console ..........................................................................112
B.3.10 Enabling/disabling full screen mode ....................................................................112
8Heading 1 - Template guidance............................................................................................................................. 113
8.1 Heading 2 ........................................................................................................................113
8.1.1 Heading 3 ............................................................................................................113
8.2 Headings use sentence style capitalization ...........................................................................113
8.2.1 Like this ..............................................................................................................113
8.2.2 Not Like This .......................................................................................................113

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8.3 Captions, tables, figures, and equations ..............................................................................113
8.4 Bullets and numbered text ................................................................................................. 114
8.5 Notes, bold text, italicized text, and document names ...........................................................115
8.6 Watermarks......................................................................................................................115
9Second ‘Heading 1’ heading................................................................................................................................... 116
Appendix C - Sample appendix title ............................................................................................................................... 117
C.1 Appendix H2.....................................................................................................................117
C.1.1 Appendix H3 ........................................................................................................117
C.2 Table and Figure captions for use in Appendices ..................................................................117
List of Figures
Figure 2-1. G.FIT use case illustration ........................................................................................... 14
Figure 4-1. Fitness equipment state machine .................................................................................. 17
Figure 4-2. G.FIT pairing zones ..................................................................................................... 21
Figure 4-3. Order of G.FIT configuration commands ........................................................................ 22
Figure 4-4. Event handling (ANT) .................................................................................................. 24
Figure 4-5. Event handling (BLE) ................................................................................................... 25
Figure 5-1. Using BLE to set the user weight .................................................................................. 33
Figure 5-2. Using BLE to set a manufacturer specific value ............................................................... 34
Figure 5-3. Notifying a display of a new manufacturer specific value ................................................. 35
Figure 6-1. Viewing received data pages on SimulANT+ ................................................................... 37
Figure 7-1. Serial message general packet structure ........................................................................ 39
Figure 7-2. Extended serial message types ..................................................................................... 40
Figure 7-3. Extended serial command ............................................................................................ 40
Figure 7-4. Extended serial request ............................................................................................... 41
Figure 7-5. Extended serial response ............................................................................................. 41
Figure 7-6. Extended serial event .................................................................................................. 41
Figure 7-7. Example: Setting FE metrics serial command (0xE1) ....................................................... 60
Figure 7-8. Example: Successful spin down calibration process (ANT) ................................................ 81
Figure 7-9. Example: Successful spin down calibration process (BLE) ................................................ 82
Figure 7-10. Example: Cancelled spin down calibration process (ANT) ............................................... 83
Figure 7-11. Example: Cancelled spin down calibration process (BLE) ................................................ 84
Figure 7-12. Example: Requested spin down calibration process (BLE) ............................................... 84
Figure 13. Sequence diagram: proximity pairing mode hr events ....................................................... 92
Figure 14. Sequence diagram: channel ID based pairing mode connection ......................................... 93
Figure 7-15. Sequence diagram: disconnecting from connected monitor device B ................................ 94
List of Tables
Table 5-1. Representations of resistance by context ........................................................................ 28

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Table 5-2. Representations of resistance by data characteristic ........................................................ 29
Table 5-3. Example transmitted resistance values ........................................................................... 29
Table 5-4. Service characteristics (primary service) ......................................................................... 30
Table 5-5. Custom control point characteristic structure................................................................... 30
Table 5-6. Op code and parameters ............................................................................................... 30
Table 5-7. G.FIT BLE response codes ............................................................................................. 30
Table 5-8. Custom data characteristic structure .............................................................................. 31
Table 5-9. Op code and parameters ............................................................................................... 31
Table 6-1. G.FIT ANT+ manufacturer specific page format ............................................................... 36
Table 7-1. G.FIT response codes ................................................................................................... 41
Table 7-2. gfit_fep_set_state_ command message ........................................................................... 44
Table 7-3. gfit_fep_set_state_ response message ............................................................................ 45
Table 7-4. gfit_fep_set_channel_configuration command message .................................................... 46
Table 7-5. gfit_fep_set_channel_configuration response message ..................................................... 46
Table 7-6. gfit_hrp_set_pairing_mode command message ................................................................ 47
Table 7-7. gfit_hrp_set_pairing_mode response message ................................................................. 47
Table 7-8. gfit_hrp_set_inuse_scan_timeout command message ....................................................... 48
Table 7-9. gfit_hrp_set_inuse_scan_timeout response message ........................................................ 48
Table 7-10. gfit_hrp_set_pairing_proximity command message ......................................................... 49
Table 7-11. gfit_hrp_set_pairing_proximity response message .......................................................... 49
Table 7-12. gfit_hrp_pair_to_device command message ................................................................... 50
Table 7-13. ANT and BLE channel IDs ............................................................................................ 50
Table 7-14. gfit_hrp_pair_to_device response message .................................................................... 51
Table 7-15. gfit_hrp_disconnect_device command message .............................................................. 52
Table 7-16. gfit_hrp_disconnect_device response message ............................................................... 52
Table 7-17. gfit_enter_bootloader command message ...................................................................... 53
Table 7-18. gfit_enter_bootloader response message ...................................................................... 53
Table 7-19. gfit_fep_set_inuse_adv_timeout command message ....................................................... 54
Table 7-20. gfit_fep_set_inuse_adv_timeout response mess age ........................................................ 54
Table 7-21. gfit_fep_set_equipment_type command message ........................................................... 55
Table 7-22. gfit_fep_set_equipment_type response message ............................................................ 56
Table 7-23. gfit_fep_set_XX_data command message ...................................................................... 58
Table 7-24. gfit_fep_set_XX_data response message ....................................................................... 58
Table 7-25. Field lengths .............................................................................................................. 59
Table 7-26. Treadmill field IDs and field lengths ............................................................................. 61
Table 7-27. Trainer/indoor bike field IDs and field lengths ............................................................... 62
Table 7-28. Elliptical/cross trainer field IDs and field lengths............................................................ 63
Table 7-29. Rower field IDs and field lengths ................................................................................. 64
Table 7-30. Step climber field IDs and field lengths ......................................................................... 65
Table 7-31. gfit_hrp_set_heart_rate command message ................................................................... 66

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Table 7-32. gfit_hrp_set_heart_rate response message .................................................................... 66
Table 7-33. Device ID to channel ID conversion .............................................................................. 67
Table 7-34. gfit_fep_set_device_id command message .................................................................... 67
Table 7-35. gfit_fep_set_device_id response message ..................................................................... 68
Table 7-36. fe_command_product_info command message ............................................................... 69
Table 7-37. fe_command_product_info response message ................................................................ 69
Table 7-38. Product information types and values ........................................................................... 70
Table 7-39. gfit_fep_send_command_update command message ...................................................... 71
Table 7-40. gfit_fep_send_command_update response message ....................................................... 71
Table 7-41. fe_command_status_update command message ............................................................. 72
Table 7-42. fe_command_status_update response message .............................................................. 72
Table 7-43. Status type ................................................................................................................ 73
Table 7-44. Status parameters ...................................................................................................... 74
Table 7-45. gfit_fep_abort_pending_commands command message ................................................... 75
Table 7-46. gfit_fep_abort_pending_commands response message .................................................... 75
Table 7-47. gfit_fep_set_max_resistance command message ............................................................ 76
Table 7-48. gfit_fep_set_max_resistance response message ............................................................. 76
Table 7-49. gfit_fep_spin_down_ command message ....................................................................... 77
Table 7-50. gfit_fep_spin_down_ payload ....................................................................................... 79
Table 7-51. gfit_fep_spin_down_ response message ........................................................................ 80
Table 7-52. gfit_fep_send_custom_event command message ............................................................ 85
Table 7-53. gfit_fep_send_custom_event response message ............................................................. 85
Table 7-54. gfit_fep_send_manufacturer_specific_page command message ........................................ 86
Table 7-55. gfit_fep_send_manufacturer_specific_page response message ......................................... 86
Table 7-8. gfit_fep_set_transmission_pattern command message ...................................................... 87
Table 7-9. gfit_fep_set_transmission_pattern response message ....................................................... 87
Table 7-56. gfit_get_version_string request message ....................................................................... 89
Table 7-57. gfit_get_version_string response message .................................................................... 89
Table 7-58. gfit_event_receive_heart_rate_ event message .............................................................. 91
Table 7-59. Session command event message ................................................................................. 95
Table 7-60. gfit_event_set_target_ event message .......................................................................... 96
Table 7-61. Target types .............................................................................................................. 96
Table 7-62. gfit_event_set_simulation_parameters event message .................................................... 97
Table 7-63. gfit_event_set_user_data event message ...................................................................... 98
Table 7-64. Spin down calibration event message ........................................................................... 99
Table 7-65. gfit_event_entering_bootloader event message ............................................................100
Table 7-66. gfit_event_custom event message ...............................................................................101
Table 7-67. Request to retrieve ANT ID .........................................................................................102
Table 7-68. ANT ID read response message ...................................................................................102
Table 7-69. RSSI calibration offset message ..................................................................................103

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Table 7-70. RSSI calibration offset response message .....................................................................103
Table 8-1. Table captions go over table ........................................................................................113
List of Equations
Equation 5-1. Interpreting transmitted resistance values .................................................................. 29
Equation 7-1. Calculating gfit_fep_set_XX_data length ..................................................................... 59
Equation 8-1. Deriving the scale factor .........................................................................................113