Energy harvesting power output measurement apparatus and methods for cycling

A portable rechargeable power meter apparatus for a bicycle;

• said bicycle including a power transmission system;
• said power transmission system including pedals configured for rotation about an axis upon application of a pedaling force;
• said power meter comprising:
• (i) a sensor comprising one or more piezoelectric elements positioned at one or more locations along said power transmission system, with said sensor configured to produce an analog electrical signal upon application of said pedaling force;
• (ii) a board comprising a plurality of electronic components, including:
• (a) a force measurement unit operatively coupled to the sensor for measuring the analog electrical signal and converting it into a binary value corresponding to the analog electrical signal;
• (b) an inertial measurement unit for measuring one or more parameters and providing respective binary values corresponding to said one or more parameters;
• wherein said one or more parameters are selected from the group consisting of acceleration, rotation rate, and magnetic heading;
• (c) an on-board processor configured to receive said binary values from the force measurement unit and the inertial measurement unit and to process said binary values;
• (d) a transmitter for sending the binary values to a remote analysis processor;
• and,
• (e) an electrical supply for powering said electronic components;
• (iii) an energy harvester comprising said one or more piezoelectric elements operatively coupled to said power transmission system for harvesting energy upon application of said pedaling force;
• and,
• (iv) charging circuitry configured to provide the harvested energy to the electrical supply, whereby in use the power supply is maintained in a properly charged state.