DIY Small Motion-Sensing LED Light Guide

If you're interested in DIY small motion-sensing lights, you might want to check out this article.

Before we start making a DIY small motion-sensing light, let's take a look at the two things in the picture below.

The two images above show a 24G (not 2.4G) human presence sensing module.

Advantages: It's very compact, has a light sensor, works with 5-12V power, can be directly configured via Bluetooth on your phone, or connected to a microcontroller via serial. The sensing distance is adjustable, the sensitivity is good, and it can detect someone sitting still within range. It's also directional, so if you place it under the side of a bed, it's quite suitable.

Disadvantages: The standby power consumption is a bit high (around 0.4W), so it's not ideal for battery power.

The other item is the small LED shown in the picture above. It has built-in constant current, so it doesn't matter which way it's connected. In tests, it works stably between 7-15V, emits soft light, and is small and convenient for DIY projects.

You need to design and draw your own schematic first, and then you can start printing.

As shown in the picture above, this is the lid of the case.

As shown in the picture above, it's powered by USB 5V, so you need to add a boost module to raise the voltage to 8V. This is within the normal operating range for both the radar module and the LED.

Next, you can start assembling. The radar module only outputs a logic signal, so you'll also need a transistor to control the LED. The 3D-printed case isn't perfectly precise, and with limited design experience, you'll inevitably need to file and adjust it a bit.

The finished product looks like the picture above.

The end.