DIY Infrared Motion-Sensing Light with TM2291

If you're interested in DIY infrared motion-sensing lights, take a look at this article.

Based on the TM2291 (part number C81387), this infrared motion-sensing light integrates lithium battery charging, battery protection, breathable battery level indicator, boost constant current drive, and warm/white light switching.

There are plenty of motion-sensing lights on the market. The cheaper ones lack features or are poorly made, while the more expensive ones don't offer good value. So why not try DIY-ing one yourself?

Control Section: The TM2291 low-power infrared motion sensing chip standard application circuit. Repeat time, delay time, lockout time, and light sensitivity threshold are all adjustable.

Charging Section: TYPE-C input with TP4056 charging and lithium protection chip.

LED Driver: The SY7200 boost constant current driver with 8 LEDs in series, with warm/white light switching.

Battery Indicator: The ATTINY13A microcontroller is used for the red-green-blue mixed color breathing indicator (red/yellow/green/cyan/blue). The three buttons are also connected in parallel and act as a support bracket for the Fresnel lens-S9008. Press the button once to show the breathing light color, indicating the battery level. While charging, the light will continuously breathe, with the blue light staying on once fully charged to indicate completion.

Switch: A 2-position switch to toggle between warm and white light, and a 3-position switch for always-on/off/auto mode.

Performance Parameters:

· Power supply: 50x30mm lithium battery.

· Charging: TYPE-C interface, default charging current 580mA.

· Shutdown static current: <10uA.

· Auto-sensing static current: <70uA.

· Lighting power: 1W.

· PCB size: 50x50mm

· Housing size: 54x54x15mm + protruding lens

Note: The TM2291 chip without peripheral circuitry indeed has only a few microamperes of static current. After adding the peripheral circuits, the total static current can be controlled within 50uA. (The IB pin with a 1M resistor to ground increases the current consumption by about 25uA, the sensing head outputting to 47k to ground is about 10uA, and the light-sensitive section is 3uA.)

Charging breathing light effect is shown below:

3D preview image is shown below:

Static current test: Tests were conducted in both auto-sensing mode and shutdown mode. The shutdown current mainly consists of the static currents of the microcontroller, lithium protection chip, and constant current boost chip.

Lighting power: The preset power is 1W, thanks to the ultra-high efficiency of the SY7200. Essentially, all the 1W power is used by the LED, which makes it brighter than other motion-sensing lights of the same power. Additionally, the LED brightness remains consistent throughout the battery discharge process.

Light emission effect is shown below:

3D model of the housing, with two types of top covers to choose from: one requires an acrylic panel for the window, while the other requires a light-transmitting material for printing the top cover, which then directly serves as the lampshade.

Physical product image is shown below:

Completed.