Don’t go towards the light! Why bother when the light will go towards you? At least that is how things work with hardware hacker Ravi Singh’s latest project called AmbiSense, which is probably the coolest nightlight you have ever seen. Singh designed a strip of lights that will follow a person and illuminate their path using a few simple and inexpensive components. It is intended for use on staircases and in hallways, but AmbiSense is perfect for getting anywhere you need to go at night without turning on a bright light that will disrupt your sleep schedule.
AmbiSense is built around an ESP32-C3 Super Mini microcontroller development board. This board is wired up to a LD2410C human presence sensor that operates using millimeter-wave radar, which conveniently works under any lighting conditions. For illumination, the device uses a strip of individually addressable WS2812B RGB LEDs, perhaps better known as NeoPixels. The hardware is all powered via 5V DC supplied by a standard USB cable, and the driving hardware was fitted into a tiny, custom 3D-printed case to keep things nice and neat.
The circuit diagram (📷: Ravi Singh)
The method of operation is simple — the person sensor reports when and where someone is present, and that information is used to light up a subset of the LED strip in the vicinity of their location. As they move, the LEDs follow them. When they move away, the lights all turn off. This effect causes a lighted path to appear before any passersby that provides only the light they need, no more and no less.
Firmware for the system was developed using Arduino IDE. In addition to the basic functionality, Singh also developed a web-based management application. This tool allows users to specify how long of a light trail AmbiSense should produce, the colors that should be displayed, and much more. No Wi-Fi connection is required for use of the nightlight in general. But when managing AmbiSense, a user connects to it as an access point then loads an IP address on the local network in a web browser.
Assembling the hardware (📷: Ravi Singh)
The parts for the build only cost about $20 to $30, with the length of the light strip being the main determining factor. If you want to light up an airport runway, you will naturally have to adjust your budget. The build process itself is very simple, and should take no more than a couple hours, so you can be feeling light on your feet in no time. Singh has provided instructions in the video, and the firmware is available on GitHub, so that will shave a lot of time off of reproducing AmbiSense.
Be sure to check out the video — this is one that you have to see to fully appreciate.
