Today we had a look at some of the internals for the next phase of the data buoy project, water quality sensing. This is an extension of the wave dynamics monitoring, and in this first session we laid out the circuitry for one of the four Atlas Scientific sensors from whitebox.ch we will be using, with an Arduino MKR LoRa board.
We placed all the components for one sensor circuit on the breadboard, and wired up a serial multiplexer, that’s the yellow circuit with the blue light in the photo, which allows us to read up to 9 sensors on one serial (tx/rx) connection to the Arduino. The sensor and circuits worked just fine, and we were able to begin logging the data to a .csv file on the SD card, with just a few changes to the sample code. A latte frothing pitcher full of hot water and measuring cup with ice water served as an extreme ocean stratification test!
For the moment only two ports on the multiplexer are reading (the same thermometer) and the GPS latitude and Longitude, speed and epoch time are just dummy data. But since we have the GPS circuit, solar power and sunnybuddy charger all set up, it’ll be straightforward to put them all together for a proper test.
Next up: Ph, Salinity (electroconductivity), and Dissolved Oxygen sensors, plus a depth sensor…