First forum post, so please bear with me!
I'm working on automating the pump and boiler on an outdoor swimming pool.
I'm planning on using a Pi, some DS18b20 temperature sensors, a DN40 1.5 inch water flow sensor and a 433mhz transmitter to control some HomeEasy brand mains sockets.
The temperature sensors seem fairly straightforward. The 433mhz remote stuff looks trickier, but it seems like I may be able to use PiSwitch to sample the codes from the existing remote and replay them. Failing that it seems that rigging the output from the receiver to a PC soundcard and using Audacity should work.
The area I'm least clear on is wiring the DN40 hall effect sensor: it seems that reading the output is a matter of using WiringPi's ISR function to count the pulses, but I'm not certain whether I can use the Pi's 5v pin to power the sensor or not. The specs seen to indicate 5v-24v (http://m.aliexpress.com/item-desc/1188433806.html), so I assume it would be OK, but could do with a bit of expert guidance. Does anyone have any experience using this kind of sensor?