The MQ-135 responds broadly to several gases and vapors. After calibration it can track relative air-quality changes, but by itself it is not a…
An Arduino and DS3231 can trigger reminders from a user-entered schedule, but the project must not prescribe a dose or time. The authoritative source is…
Our earlier Arduino voltmeter article showed a precise numeric reading; this project trades some of that precision for something faster to read at a…
Batteries and supercapacitors store energy through different mechanisms, so neither should be selected from capacitance or voltage alone. Runtime, peak…