I am a brand-new user, just starting to fiddle with the hardware I recently ordered. In trying to brainstorm a case for the hardware, I have come up with something that will be useful for me, but I need some help getting started.
I own a 40-year-old boat that has a handful of 32V bilge pumps installed. I would like to know if there is a way to monitor the bilge pumps for activity and be notified when one of them is activated. I would rather not monitor the actual fluid level. I just want to know when the pump actually turns on and off, which presumably could be done by monitoring current flowing (or not) through the electric wires.
I would start by looking at a current sensor, similar to this Adafruit INA169. This is a 60VDC 5A sensor, but there are bigger ones available from different manufacturers. You'd just connect one of these inline with each pump's power supply to monitor the current flowing to that pump.
I would echo @rickkas7 but suggest the Adafruit INA260, whereas the INA169 outputs a voltage proportional to the DC current, this one can be read over I2C bus and is compatible with Particle devices running on 3V3 and not 5V tolerant. You didn't mention which Particle device you were considering using. Another option is to use a module based upon a Hall effect based sensor rather than a shunt resistor - a module based upon a ACS712 IC.