1-Wire Twilight Sensor
The twilight sensor provides a means for my
Home Control System to know whether it is dark or light outside. This is needed to decide when to open or close curtains and to decide if security lights need to be enabled. It is mounted on the side of my house under the roofline and is north facing.
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I've looked several ways to achieve this function but, decided to use a pre-built module from Maplin to provide the basic functionality. I'm not sure they still sell them though. The module is a Kemo M122  and it is has a low current relay within it, which is interfaced to a DS2405 device. It requires a 12V power supply and is fed from my 1-Wire Network directly.
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Wiring
The PIR is wired up using burglar alam wire to a 4-pin PCB connector (Maplin part no. HB58N). This plugs in to my
1-Wire PIR board. The wiring to the pins are:
- Pin 1 (red) = +12V
- Pin 2 (black) = 0V
- Pin 3 (blue) = Signal (+12V = dark, 0V = light)
