I was hoping to learn how to use the SD16_A inside the MSP430_213 to build a circuit to measure (roughly) a persons heart rate or pulse rate by pressing an electrode against a finger (i.e. a sensor in a ring).
Does that sound feasible? Would I need two electrodes?
Does anyone have the analog expertise of how to couple a signal off the skin on the finger?
Electrodes will only work if placed on the chest, you need two of them - one on the sternum and one on the side of the chest. They should be silver/silver chloride. Quite a lot of low-noise amplification is needed and filtering to get rid of 50 Hz from the mains.
You can detect pulse rate from blood flow in the finger or ear lobe using electro-optical techniques with a red LED and photo-diode.