Use of gyroscopes in personal fitness tracking devices and bicycling activities

1. A biometric monitoring system comprising:

a first housing configured to be mounted on a rotating component of a bicycle drivetrain;

an angular motion sensor located in the first housing;

a memory; and

control logic, wherein:

the control logic, the memory, and the angular motion sensor are configured to be communicatively connected with one another, and

the control logic is configured to:

a) obtain angular motion data from the angular motion sensor,

b) determine each time a full crank revolution of the bicycle drivetrain is indicated, at least in part, by the angular motion data,

c) alter information stored in the memory and pertaining to cadence based on the number of crank revolutions per unit time and responsive to (b),

d) determine that the angular motion data from the angular motion sensor indicates that the rotational axis of the rotating component to which the first housing is mounted is experiencing an oscillating tilt about an axis perpendicular to the rotational axis, and

e) alter information stored in the memory and pertaining to a degree of side-to-side rocking motion of the bicycle based on the determination in (d).

2. The biometric monitoring system of claim 1 , wherein the first housing is configured to be mounted on a rotating component of a bicycle drivetrain selected from the group consisting of: a crank arm, a spider, a chainring, a front sprocket, a pedal axle, a sprocket guard, and a pedal.

3. The biometric monitoring system of claim 1 , wherein the control logic is further configured to:

d) determine a degree of deviation of the cadence over time, as indicated by the angular motion data, with respect to a baseline cadence and based on variations in rotational speed of the angular motion sensor about a rotational axis, and

e) alter information stored in the memory and pertaining to the degree of deviation of the cadence over time responsive to (d).

4. The biometric monitoring system of claim 1 , wherein the control logic is further configured to:

d) determine a degree of deviation of the cadence over time, as indicated by the angular motion data, with respect to a baseline cadence and based on variations in rotational speed of the angular motion sensor about a rotational axis, and

e) alter information stored in the memory and pertaining to the degree of deviation of the cadence as a function of pedal stroke responsive to (d).

5. The biometric monitoring system of claim 3 , further comprising a display, wherein the control logic is further configured to:

cause the display to present an indication of cycling form based on the information pertaining to the degree of deviation of the cadence over time.

6. The biometric monitoring system of claim 3 , wherein the baseline cadence is an average cadence for a predetermined number of preceding consecutive crank revolutions.

7. The biometric monitoring system of claim 3 , wherein the baseline cadence is an average cadence during a predetermined period of time.

8. The biometric monitoring system of claim 3 , wherein the baseline cadence is a user-specified cadence.

9. The biometric monitoring system of claim 1 , wherein the control logic is further configured to:

d) determine a degree of deviation in rotational speed of the angular motion sensor over time, as indicated by the angular motion data, with respect to a baseline rotational speed, and

e) alter information stored in the memory and pertaining to the degree of deviation in rotational speed responsive to (d).

10. The biometric monitoring system of claim 1 , wherein the control logic is further configured to:

d) determine a degree of deviation in rotational acceleration of the angular motion sensor over time, as indicated by the angular motion data, with respect to zero rotational acceleration, and

e) alter information stored in the memory and pertaining to the degree of deviation in rotational acceleration responsive to (d).

11. The biometric monitoring system of claim 1 , further comprising a display, wherein the control logic is further configured to:

cause the display to present an indication of cycling form based on the information pertaining to the degree of side-to-side rocking motion.

12. The biometric monitoring system of claim 1 , wherein the angular motion sensor is selected from the group consisting of: (i) a true gyroscopic sensor and (ii) a simulated gyroscopic sensor that uses sensors selected from the group consisting of: two or more accelerometers, a magnetometer, and combinations thereof.

13. A method comprising:

a) obtaining angular motion data from an angular motion sensor,

b) determining each time a full crank revolution of a bicycle drivetrain is indicated, at least in part, by the angular motion data,

c) altering information stored in a memory and pertaining to cadence based on the number of crank revolutions per unit time and responsive to (b),

d) determining that the angular motion data from the angular motion sensor indicates that the rotational axis of a rotating component to which the first housing is mounted is experiencing an oscillating tilt about an axis perpendicular to the rotational axis, and

e) altering information stored in the memory and pertaining to a degree of side-to-side rocking motion of the bicycle based on (d).

14. The method of claim 13 , wherein the angular motion sensor is mounted on a rotating component of a bicycle drivetrain selected from the group consisting of: a crank arm, a spider, a chainring, a front sprocket, a pedal axle, a sprocket guard, and a pedal.

15. The method of claim 13 , further comprising:

d) determining a degree of deviation of the cadence over time, as indicated by the angular motion data, with respect to a baseline cadence and based on variations in rotational speed of the angular motion sensor about a rotational axis, and

e) altering information stored in the memory and pertaining to the degree of deviation of the cadence over time responsive to (d).

16. The method of claim 13 , further comprising:

d) determining a degree of deviation of the cadence over time, as indicated by the angular motion data, with respect to a baseline cadence and based on variations in rotational speed of the angular motion sensor about a rotational axis, and

e) altering information stored in the memory and pertaining to the degree of deviation of the cadence as a function of pedal stroke responsive to (d).

17. The method of claim 15 , further comprising:

causing a display to present an indication of cycling form based on the information pertaining to the degree of deviation of the cadence over time.

18. The method of claim 15 , wherein the baseline cadence is an average cadence for a predetermined number of preceding consecutive crank revolutions.

19. The method of claim 15 , wherein the baseline cadence is an average cadence during a predetermined period of time.

20. The method of claim 15 , wherein the baseline cadence is a user-specified cadence.

21. The method of claim 13 , further comprising:

d) determining a degree of deviation in rotational speed of the angular motion sensor over time, as indicated by the angular motion data, with respect to a baseline rotational speed, and

e) altering information stored in the memory and pertaining to the degree of deviation in rotational speed responsive to (d).

22. The method of claim 13 , further comprising:

d) determining a degree of deviation in rotational acceleration of the angular motion sensor over time, as indicated by the angular motion data, with respect to zero rotational acceleration, and

e) altering information stored in the memory and pertaining to the degree of deviation in rotational acceleration responsive to (d).

23. The method of claim 13 , further comprising:

Causing a display to present an indication of cycling form based on the information pertaining to the degree of side-to-side rocking motion.

24. The method of claim 13 , wherein the angular motion sensor is selected from the group consisting of: (i) a true gyroscopic sensor and (ii) a simulated gyroscopic sensor that uses sensors selected from the group consisting of: two or more accelerometers, a magnetometer, and combinations thereof.