An ECE project using perfboard as final product
One issue that has long concerned me is that spending extended periods in a closed room often leads to drowsiness, and by the time I become aware of this condition, the indoor air is already stale. Hence, I designed and built an Environmental Quality Monitor (EQM) to address this problem.
The EQM is a microcontroller-based system designed to measure temperature, humidity, atmospheric pressure, and carbon dioxide (CO₂) concentration, as well as to provide warnings and alerts when environmental conditions become uncomfortable, or even potentially harmful, to residents.
A TFT display module was used to present sensor readings as well as warning and alert messages, in combination with green, yellow, and red LEDs to provide a clearer visual feedback.
Based on several days of experimentation, I observed that when the carbon dioxide concentration exceeds 2000 ppm, I begin to feel sleepy. Therefore, the warning threshold for carbon dioxide concentration was set at 2000 ppm, at which the yellow LED is activated and a warning message recommending ventilation is displayed.
Additional environmental warnings were also configured, including alerts for high temperature and high humidity.
Now, I can ventilate the room before feeling sleepy!