This Infrared Human Sensor reference design detects human presence/absence using an infrared sensor, and turns on/off a high brightness LED automatically. It can be applied to a wide range of applications including office lights and automatic doors.
The infrared LED sending signal is controlled by Renesas' RL78/G10 MCU's timer array unit (TAU01), and the receiving signal is controlled by the timer array unit (TAU00) and external interrupt terminal (INTP0). When a person is detected, the high brightness LED will light up. Once the person leaves the detection area after 10 seconds, the LED will go off and the system will enter an infrared receiving signal STOP mode. RL78/G10 offers the lowest current consumption in the industry and is ideal for human sensing.
The Infrared Human Sensor solution features the RL78/G10 10-pin LSSOP general purpose microcontroller. The sensor is inexpensive and provides energy savings. It is ideal for temporary lighting in entrances, porches, stairs, and bathrooms. For example, when people approach, the bulb lights up, when they leave, the bulb goes out automatically.
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.
- Demo board includes the RL78/G10 MCU
- Infrared detection function includes an infrared signal emitting circuit and an infrared receiving detection circuit
- In infrared detection status, the system executes the infrared signal emitting task and the infrared receiving detection task at the same time
- If a human body is detected, LED lighting is turned on for 10s; when the LED is ON, infrared detection stops. After 10s, the LED goes out. The system continues to detect whether the human body comes close or not according to the interval time controlled by a watchdog timer interrupt
- The system uses a 40kHz infrared carrier wave signal, to reduce interference
- When the system is idle, it enters infrared detection status every 400ms