Saturday, February 5, 2011

Heart rate measurement from fingertip

This projects describes an optical method to measure heart rate through fingertip. The volume of blood inside the finger artery varies with heartbeat. When an infrared light is passed through the fingertip, the amount of light absorbed is directly related to the blood volume. A photodiode senses this change in absorption and the signal is amplified further with a two stage filter/amplifier. The microcontroller reads the output from the amplifier and display the heart rate on a 3-digit seven segment LEDs.


Wednesday, January 5, 2011

Lessons for first time Propeller Programmers

If you are looking for beginner's lessons on Propeller microcontroller, these tutorials will be very helpful.


Digital timer relay switch

A programmable digital timer switch based on a PIC16F628A microcontroller. You can set both on and off time using push button switches. The program menu, and time information is displayed on a LCD screen.