The PM2. 5 Monitor is a portable device that can measure and detect the concentration of atmospheric particulate matter (PM) of less than 2. 5 micrometers in real-time. The density is displayed on an LCD panel with LED indicators to show the air quality. It also has a charging and power supply function as a mobile battery, and displays battery capacity with four LEDs. If the preset concentration threshold is exceeded or the battery voltage drops below 2. 8V, it will inform you with a buzzer.
This solution features the RL78/L12 low power consumption, compact LCD MCU which includes functions such as I/O port, A/D converter, buzzer, LCD controller, STOP mode, etc. The device is best suited for small home appliances. In addition, the ISL97656 (DC/DC converter IC) controls battery discharge and the ISL6294 (battery charger IC) controls charging. The threshold value and PM2. 5 concentration data are saved in EEPROM (if the data amount is less than 2KB, you may also use the data flash built in RL78/L12).
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- Demo board includes the RL78/L12 MCU
- When the outside PM2.5 concentration value is larger than the pre-set value, the buzzer (about 80dB) will sound at 1s intervals
- When the battery is low, the buzzer (about 80dB) will sound at 2s intervals
- Charge indicator:
- If the battery is charging, the charge indicator light will stay on and the battery remaining indicator light will steadily blink
- If the charging is complete, the charge indicator light will stay off and the battery remaining indicator will display normally
- Battery remaining indicator:
- Different status of the 4 LED lights show the remaining battery amount