Eliminate bacterial transmission with the Automatic Liquid Dispenser featuring the Renesas RL78/G11 microcontroller and ISL9001A high performance low dropout linear regulator (LDO).
This Automatic Liquid Dispenser reference design is for hands-free dispensing of liquids such as soap, hand sanitizer, shampoos, or hand lotions. Automatic liquid dispensers are popular in public places and private institutions, as touch-free designs eliminate bacterial transmission. The dispenser only distributes a set amount of liquid per motion activation to minimize waste. When a hand is detected near the nozzle, the MCU triggers the pump motor and the dispenser emits liquid. The liquid is automatically dispensed without the hand touching any part of the nozzle, resulting in a more hygienic environment. When a hand comes close to the nozzle, it blocks the transfer of optics between the infrared LED and photo transistor. The MCU detects the change in the photo transistor status, and then activates the motor.
This solution features the RL78/G11 low pin and internally configurable analog MCU which operates the system clock with a medium-speed on-chip oscillator, achieving low-power consumption and a fast wake-up of 4μs.
The ISL9001A high performance low dropout linear regulator used for power management can source a current of up to 300mA. This regulator helps extend battery life as it supports a wide input voltage range (2.3V to 6.5V) while featuring extremely low quiescent current.
- 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 (66.6μs at 15kHz operation with low-speed on-chip oscillator clock)
- General-purpose registers: (8-bit register × 8) × 4 banks
- ROM: 16KB, RAM: 1.5KB, data flash: 2KB
- Selectable high-speed on-chip oscillator clock: 48/24/16/12/8/6/4/3/2/1 MHz (TYP.)
- Selectable middle-speed on-chip oscillator clock: 4/2/1 MHz (TYP.)
- On-chip debug function
- On-chip selectable power-on-reset (POR) circuit
- On-chip voltage detector (LVD)
- On-chip watchdog timer (operable with the dedicated low-speed on-chip oscillator)
- On-chip key interrupt function: 8 key interrupt input pins
- On-chip clock output/buzzer output controller
- On-chip BCD (binary-coded decimal) correction circuit
- I/O port: 17 to 21
- 16-bit timer (TAU): 4 channels
- TKB: 1 channel
- 12-bit interval timer: 1 channel
- 8-bit interval timer: 2 channels
- Serial interfaces
- CSI: 4 channels
- UART: 2 channels
- I2C/Simplified I2C communication: 4 channels
- Multimaster I2C: 2 channels
- 8/10-bit resolution A/D converter: 10 to 11 channels
- 8/10-bit resolution D/A converter: 2 channels
- Comparator: 2 channels
- Operating modes: Comparator high-speed mode, comparator low-speed mode, window mode
- PGA: 1 channel
- Data transfer controller (DTC)
- Event link controller (ELC)
- Standby function: HALT or STOP mode
- Power supply voltage: VDD = 1.6V 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.