Motion nightlight

Motion Nightlight

This is one of my first self designed PCBs in KiCad. It's a very simple circuit which can be utilized to create a motion nightlight with a few low power LED strips. See some examples at the bottom.

Credits

Shoutout to Quindor from QuinLED.info, the LED master himself. He tought me a lot about KiCad, PCB design and some more electrical engineering fundamentals! While I'm still miles away from being perfect, with his help I really feel confident in what I'm doing here!

KiCad dependencies

It might happen that KiCad is missing my custom footprints. You can find and download them here and then add them to KiCad: https://github.com/ezcGman/andys-footprints

Parts list

All these parts can be easily found on AliExpress (except the PCBs ;) ):

• 1x The PCB in this folder, printed e.g. at PCBWay
• 1x 3.2V LiFePO4 battery in AA form factor
• 1x AA battery holder for THT mounting
• The HC-SR501 PIR sensor. And because this also would act at day time, we also need:
• An LDR, a light-dependent resistor, which can be installed into the HC-SR501 to make it only act at night time. See that great video of Clive: https://www.youtube.com/watch?v=2dxhbXHYEG0
• 1x MOSFET. Probably most FETs (ha ha, MOSt FETs... ha ha) are fine, just pay attention that the thermal pad is connected to drain, as the MOSFET bed on the PCB is connected to drain! But I suggest the IRL3803 which has perfect specs for this application:
  • Max Drain-Source Voltage of 30V
  • Gate Threshold Voltage already of 1V
• 1x 0805 SMD capacitor of 10µF or bigger. But 0805 SMD caps are usually limited to ~40µF. So whatever u have around
• 1x 0805 SMD resistor of 10kΩ
• 4x 2.54mm double row pin headers. I chose angled headers, as it makes the whole thing more flat, so you can hide it behind something

Tools list

Required

• A soldering iron
• Soldering tin

Optional

• For SMD components:
  • A hot air soldering/reflow station. However, it's only two and u have space around them, so they can be done with a soldering iron. Also the MOSFET can be technically soldered with an iron.
  • Solder paste
  • Tweezers

Example installation: