A series of very low tides had the lab gals looking to do some collection. Where? Right out in front of the office. With a “meeting” scheduled on the company calendar we went for a walk along the shoreline.
Aside from a morning sharing knowledge about sea life we did indeed find several specimens of Asparagopsis taxiformis to collect.
The usual drill… A problem that can be solved by a bit of circuitry. In this case the gals in the lab were having trouble controlling the mix of gas to their cultures. They needed to feed much less CO2 to the mix, where the off-the-shelf flow gauges and needle valves became difficult to use much under one liter-per-minute.
Simple solution… Build a gas modulator, something that could turn on the gas some percent of the time, allowing easy control of small amounts of CO2 to the mix. A timer and a gas solenoid… Easy.
There is nothing particularly interesting about the circuitry. A seven segment display, a few switches, and a power transistor to control an external solenoid. All very basic. It is the controller that is new, at least for me. An Arduino provides the programmable part of this project.