The YosemiTech are a great deal and are very well made (http://www.yosemitech.com/en/product-cat-2.html). At the Stroud Water Research Center, we ordered one each of conductivity, turbidity and DO to test them out over the summer. When connected to a computer, they worked great.
However, we unfortunately haven’t had the time to work out how to get them to communicate with our Arduino compatible Mayfly logger boards. All the YosemiTech sensors communicate using RS-485 with MODBUS protocols, which is a new communication protocol for our team. We’ve glanced at some of the work done on this, such as https://github.com/smarmengol/Modbus-Master-Slave-for-Arduino, but just haven’t had time to play with it.
Has anyone on this forum figured out how to connect a RS-485/MODBUS sensor to an Arduino? If so, please point us to some examples.