Custom Bed Frame – Part 8

In Part 8 I stain and apply polyurethane to the frame, make the under bed drawers and add the automatic LED night lights.

I used an ATtiny85 microcontroller with an LDR (Light Dependent Resistor) so I could have the nightlight turn on/off automatically based on light level. The LEDs run on 12v and require 1.8 amps of current (in my case given the length of strip/number of LEDs I used). A MOSFET was used to allow the ATtiny85 to turn the LEDs on/off and also allow it to control the brightness using PWM (Pulse Width Modulation).

Code and schematics (and rough Sketchup drawings of the frame) for the LED controller are available on GitHub.

Acurite 3N1TXCA1 Weather Station Teardown

Teardown of a decommissioned Acurite 3N1TXCA1 weather station. What kind of sensors and build quality do these inexpensive weather stations have?

The only two components of note are the outdoor temperature/humidity sensor and the pressure sensor (for barometric pressure readings). The most surprising thing is the piss-poor build quality of the unit.

SHT21 datasheet

DMP015A-1 datasheet

Similar (currently available) weather station

Disassembly/Inspection Of A Failed Cree LED Light Bulb

Disassembly/Inspection Of A Failed Cree LED Light Bulb
Very modular design. You could perform a non-destructive disassembly.

Disassembly/Inspection Of A Failed Cree LED Light Bulb

Disassembly/Inspection Of A Failed Cree LED Light Bulb
Yikes! Is that right? Turns out, it is.
Disassembly/Inspection Of A Failed Cree LED Light Bulb
This LED fell off during disassembly. They are not hard to get off but I wonder if this one was loose and could have been the cause/contributing to the issue the bulb was having.

Disassembly/Inspection Of A Failed Cree LED Light Bulb

Disassembly/Inspection Of A Failed Cree LED Light Bulb

Disassembly/Inspection Of A Failed Cree LED Light Bulb
Interestingly, no heat sink compound was used between the heat sink and the LED substrate.
Disassembly/Inspection Of A Failed Cree LED Light Bulb
This part was in the center of the heat sink. The bottom contacts made contact w/the driver board and the top contacts w/the LEDs.

Disassembly/Inspection Of A Failed Cree LED Light Bulb

Disassembly/Inspection Of A Failed Cree LED Light Bulb
Could the discoloration on the silk screen labeling be a sign the board was getting to hot?
Disassembly/Inspection Of A Failed Cree LED Light Bulb
Good quality, high temp rated CAPs
Disassembly/Inspection Of A Failed Cree LED Light Bulb
There was a lot more of these white cruddy spots on this inductor before this picture was taken… Not sure if this is an indication of an issue.
Disassembly/Inspection Of A Failed Cree LED Light Bulb
Some crud around the right lead of the primary capacitor. May just be left over from manufacturing. The cap looks fine, no bulging or signs of leaking.