Alan numitron clock
SNES Pi Webserver
USB Volume/USB toys
SNES Arcade cabinet
Game boy projects
Home Presence Detector
Rand Nerd Tut
Carnet du maker (fr)
ATmel blog (defunct)
home presence detector
Upon detection of a movement nearby, turn on the light ... yes, my living room is dark and messy.
Not complicated project at all, however special care must be payed since we'll be playing with the big boys and the AC wall power. If careless, at least magical smoke, at worse a fire or frying your myocard.
20101130: well, the 2 babies I made months ago (10 months ago for the 1st version) are still perfectly working with not a single issue. Mine is still in the entrance of my appartment turning on light when I walk in, and the other one at my gf appartment turning on the light when she goes to the bathroom. Quite happy to see there are some projects I can build and have it run for months.
20111101: for the record, the version 1 made in January 2010 (soon 2 years ago) is still running just fine in my entrance. I'm quite proud yes. 2 years of electronics later, I notice that yeah, the diode before the SSR could be spared, but it would have been safer to add a resistor or better, to have a transistor drive the SSR (extensively used in Clapclap 2313). Anyway, still working so colclusion the baby has internal resistance and does not require much more than 20mA otherwise the uC would have fried long ago... lucky me!
Total : around 3,000 jpy. Work time : 10 days. Time to build a new one : about 1 day with the casing I would say.
On detection of a movement, the ALARM pin goes low (after a 1-2 sec of initial configuration). Since the pin goes DOWN, one must pull it UP to make sure to have appropriate reading. And by the way, beware of your pull up: make it 5v and not 9v to not fry the uC.
Another thing to remember is that even if it says "works from 5v to 12v", it seems that the device works better in the 9-12 v range (according peoples comment here and there). So the circuit will have a 9v rail (wallwart direct) and a 5v (LM7805 managed).
According documentation don't forget a 10 uF condensator right near the sensor, seems it likes to make waves.
Wiring colors (according my cable delivered with the baby so read your own doc if you're unsure):
NOTABENE : put the pull up to the 9v or the 5v depends on your needs ! In my case it will be 5v.
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