We are trying to build a digital stethoscope. So far, what we've got working is an LED that pulses on and off with the heart beats (using an IR sensor & transmitter, amplified with op-amps).
The part we're stuck on is generating the beats per minute based on 10 second or 20 second samples. We're trying to find out how to make a sub-circuit to count the number of beats in either the 10 second or 20 second timespan and then use a binary multiplier to multiply by 6 or 3 to get the BPM.
So are we on the right track? What's the best way to go about implementing this. Oh and we are not allowed to use microcontrollers or multipurpose chips. The circuit we have right now runs on a single 9V battery.
Thanks!
The part we're stuck on is generating the beats per minute based on 10 second or 20 second samples. We're trying to find out how to make a sub-circuit to count the number of beats in either the 10 second or 20 second timespan and then use a binary multiplier to multiply by 6 or 3 to get the BPM.
So are we on the right track? What's the best way to go about implementing this. Oh and we are not allowed to use microcontrollers or multipurpose chips. The circuit we have right now runs on a single 9V battery.
Thanks!