Fluid flow metering device and method thereof

A fluid flow metering device, comprising:

• a fluid flow detector, disposed in a supply tube of a fluid flow provider;
• a memory;
• a micro controller, coupled to the fluid flow detector and the memory;
• and
• a power generator, disposed in the supply tube and is coupled to the fluid flow detector, the memory and the micro controller,
• wherein when a fluid flows in the supply tube, the power generator generates a first supplying power through flow of the fluid by converting kinetic energy of the flow of the fluid to electric energy, and provides the first supplying power to the fluid flow detector, the memory and the micro controller,
• when the fluid flow detector detects the flow of the fluid, the fluid flow detector detects the flow of the fluid outputted from the supply tube to derive a detecting value,
• wherein the micro controller has a low power supply mode and a high power supply mode,
• wherein the micro controller is in the high power supply mode when the micro controller receives a second supplying power,
• when in the low power supply mode, the micro controller receives the detecting value and writes the detecting value into the memory, and when in the high power supply mode, the micro controller converts the detecting value into a flow value and writes the flow value into the memory.