DIY Night Light with NSA3182 FT100 Processor

If you're interested in disassembling and modifying a night light based on the NSA3182 FT100 infrared pyroelectric processor, take a look at this article.

The night light is shown in the image below, with a warm color scheme.

Model Number on the Bottom of the Night Light:

The internal structure of the night light includes infrared pyroelectric triggering, a MicroUSB charging port, and six warm color LEDs.

The pyroelectric processor used is the NSA3182FT100, which is not the commonly used BISS0001.

About the NSA3182:

The NSA3182 is a highly integrated control chip designed for pyroelectric infrared sensors (PIR). It combines all the essential components for passive infrared motion detection in a single chip. The analog front-end can be directly connected to an analog PIR sensor using a capacitor, and it includes a built-in 3V LDO to power the PIR sensor. It also features a high-precision analog-to-digital converter (ADC) to convert the sensor signal into a digital signal. The motion detection unit uses algorithms to identify moving heat sources and supports relay output to improve system resistance to interference. The sensor sensitivity threshold and alarm duration can be adjusted using external resistors.

Key Features:

· Analog PIR signal input

· Digital signal processing with human proximity alarm

· Wide voltage range (3.1V~12V)

· Output capable of driving relays and LEDs

· Adjustable sensitivity with 128-level switch time adjustment

· Ultra-low power consumption

· Built-in 3V LDO output

The LTH7/4054 is used to charge the built-in battery.

The night light's battery is a 14500 from HONGLI.

When triggered, the light stays on for about 20 seconds. If you feel the lighting duration is too short, you can modify it to extend the duration to about 30 seconds. The R4 resistor controls the lighting duration, and adjusting this resistor will change how long the light stays on.

R4 Pull-Down Resistor Value Table:

The pin 6 (OnTime pin) of the FT100 is directly connected to the pull-down resistor. You can use a multimeter's continuity setting to find it, and then simply replace the resistor to modify the lighting duration.

Pinout of NSA3182FT100:

You can use a 224/220K 0603 resistor for the modification.

Solder it onto R4, and after modification, the lighting duration will be adjusted to your preference.

It's worth mentioning that the warm-colored night light uses the FT100 solution, while another variant with a cool white light uses an unknown main control solution (unmarked chip, likely not a mainstream control solution).

The light looks like this when it's on:

Modification Complete!