My school is working on a multi year project to create a water condition monitor with remote access, this would be used in a marine environment when diving or monitoring water life.
So far we have built Raspberry Pi’s to store temperature using a Waterproof DS18B20 Digital temperature sensor. We then convert the MySQL data to a JSON web file and then can access the data remotely. I even made an iOS app to display the temperatures collected.
Our next step would be to connect all our aquariums (23) to as few Pi’s as we can and collect the data. I have been informed that we can have 75 of the sensors in 1-wire communication but we may have issues with distances etc. This seems to be going fine.
Also we would like to collect pH and Salinity. Does anyone have suggestions as to the best sensors that would allow us to collect readings easily with Raspberry Pi’s.
Measuring pH and Salinity is a bit harder than temperature as the types of sensors that can measure them typically need to be calibrated often, and should not be left immersed in water.
Here are a couple of sensors capable of making those measurements though:
Hi I am trying to do something similar with 30 aquariums, how do you connect multiple temperature probes to the Pi? I have a Pi 2 model B v1.1.
Ive just bought the power supply, I already have the temp probes, is there a specific wiring board required? I will run an ORP sensor at some stage once I get the temp data logger working
Thanks for posting, it depends on the protocol, those Temperature Probes that you’ve got, I’m assuming they’re DS18B20s?
They use the One-Wire protocol typically, which being an addressed Serial protocol, allows for easy “chaining” of multiple devices onto the same bus. Hackster.io has a tutorial on it that should have you covered for rigging up all of the sensors:
