Counting pulses, while the MM sleeps....

Author	Message
robert.rozee Guru Joined: 31/12/2012 Location: New Zealand Posts: 2552	Posted: 01:07pm 30 Sep 2025       the device used seems to be an ETA9640, see: http://www.eta-semi.com/wp-content/uploads/2022/03/ETA9640_V1.5.pdf and: https://www.ebay.com/itm/203199357809 simplest solution: integrate the pulses at the LED's anode, using a relatively high value resistor and a largish capacitor. then measure the voltage across the capacitor with one of the MX170's analog inputs. you'll need to experiment with the component values to find what is optimal, and may need a blocking diode in series with the resistor (depending on if pin 7 is pulled low when the LED is off). cheers, rob   :-)