added entry for heartbeat detection

README.md

@@ -52,4 +52,12 @@ Interact with an LED using remote-gpio. This allows you to write python code on
 
 ## remoteGpioFromPi.py
 
-Read buttons on different Pis in the VPN to trigger an LED. 
+Read buttons on different Pis in the VPN to trigger an LED.
+
+## heartbeat.py
+
+Changed the implementation of [tut RPi's Heartbeat Pulse Sensor](https://github.com/tutRPi/Raspberry-Pi-Heartbeat-Pulse-Sensor) to work with gpiozero. 
+
+Look at `heartbeat.py` for how to use it. `pulsesensor.py` is the underlying pulse detection logic. 
+
+Works in conjunction with analog heartbeat sensors and the MCP3008 ADC.