Production is ramping up for the imminent start of two field experiments in Alaska and California. In both cases we’ll be manipulating tide pool temperatures using heaters to slightly raise water temperatures during low tide. To get ready for that, I’ve been working on soldering and assembling the custom circuit boards that will handle the heating control.

These boards house a ATmega328P microcontroller and DS3231M real time clock, and they are programmed with an algorithm to calculate tide height for a specific field site based on the date and time (instead of storing a huge table of predicted tide heights in memory). When the tide is predicted to be low, the board turns on a heater circuit to begin heating the tidepool. The microcontroller also uses an INA219 current sensing chip to monitor the current draw and power usage of the heater, so that the power output of the heater can be fine-tuned in software. This also allows the software to check for faults in the heater system, and monitor battery voltage, so that everything can be shut down if needed to avoid damaging the rechargeable batteries.

This work is being supported by National Science Foundation grants 1737065 (California project) and 1904185 (Alaska project).