Measure and detect the concentration of air pollutants in real-time with the PM2.5 Monitor with Portable Battery featuring the Renesas RL78/L12 microcontroller, ISL97656 integrated FET regulator and ISL6294 single cell battery charger.
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).
- Minimum instruction execution time: Can be changed from high speed (0.04167μs at 24MHz operation with high-speed on-chip oscillator) to ultra-low speed (30.5μs at 32.768kHz operation with subsystem clock)
- General-purpose registers: (8-bit register × 8) × 4 banks
- ROM: 8KB to 32KB, RAM: 1KB to 1.5KB
- Selectable high-speed on-chip oscillator clock: 24/16/12/8/6/4/3/2/1 MHz (TYP.)
- On-chip single power supply flash memory
- On-chip debug function
- On-chip power-on-reset (POR) circuit
- On-chip watchdog timer (operable with the dedicated low-speed on-chip oscillator)
- On-chip key interrupt function
- On-chip clock output/buzzer output controller
- On-chip BCD (binary-coded decimal) correction circuit
- I/O port: 20 to 47 (N-ch open drain I/O [EVDD with stand voltage]: 2)
- 16-bit timer: 8 channels
- 12-bit interval timer: 1 channel
- Real-time clock: 1 channel
- Serial interface
- CSI: 2 channels
- UART: 1 channel
- Simplified I2C communication: 1 channel
- 8/10-bit resolution A/D converter: 4 to 10 channels
- Standby function: HALT mode, STOP mode, SNOOZE mode
- Power supply voltage: VDD = 2.0V to 5.5V
- Operating ambient temperature: TA = -40 °C to +85 °C
Disclaimer: THIS MATERIAL IS PROVIDED “AS-IS” FOR EVALUATION PURPOSES ONLY. RENESAS ELECTRONICS CORPORATION AND ITS SUBSIDIARIES (collectively, “Renesas”) DISCLAIM ALL WARRANTIES, INCLUDING WITHOUT LIMITATION, FITNESS FOR A PARTICULAR PURPOSE AND MERCHANTABILITY. Renesas provides evaluation platforms and design proposals to help our customers to develop products. However, factors beyond Renesas' control, including without limitation, component variations, temperature changes and PCB layout, could significantly affect the product performance. It is the user’s responsibility to verify the actual circuit performance.