After a certain critical distance, the heart would drop to it's natural beat (which I can program to be 72 beats per minute).
Beyond 5 feet, I want it to beat at a constant rate of 72 beats per minute
QuoteBeyond 5 feet, I want it to beat at a constant rate of 72 beats per minuteIf the heart is an LED you will not see it beat/flash the human eye would see that as a constant brightness. The limits about 10 beats/sec if you want flashes not brightness.Mark
According to wiki (?) any where between 60 and a 100! is normal for a any one over 10.
I would consider a PIR sensor as a heat related motion sensor combined with the SR or MaxBotix devices.
If you are using multiple ultrasonic sensors with a PIR, I suggest using the PIR with an interrupt (look up ISR - Interrupt Service Routine) to trigger polling each ultrasonic in turn.