I chose an Arduino Uno<\/a> as the controller. \u00a0I have a few of them around and have wanted to find an appropriate project to give them a try.<\/p>\n I hardwired a segment of LED strip to a 12V wall wart and taped them inside the clock to get a sense for how many LEDs I would need to achieve the desired effect. \u00a0I used a bit of tape to hold them in place during testing. \u00a0Two strips of 9 LEDs each did the trick. \u00a0One is placed on the top of the door frame, facing down. \u00a0This nicely illuminates the clock face. \u00a0The second is on a cross member just below the clock face. \u00a0This one faces inward and cast a great light on the mechanism and pendulum. I knew I would not be able to control the LED light strips directly. \u00a0 Each group of 3 LEDs draw 20mA under full brightness. \u00a0The configuration I settled on has 18 or 6 segments of 3. \u00a0The total current draw will be 6 x 20mA or 120mA total. \u00a0Arduinos have a max. draw of 40mA per pin so I’ll have to use a transistor with a higher current capacity. \u00a0I had a few TIP120<\/a>‘s in the parts bin so I went with those. \u00a0I’m hoping that I can run them without a heatsink.<\/p>\n A simple photo-resistor<\/a> will determine the ambient light in the room. \u00a0I’ll use this to determine when it is ‘night’ and enable the lights.<\/p>\n For the ‘people sensor’ I’m using a PIR motion sensor<\/a>. \u00a0It will run off the +5V rail of the Arduino and provides a simple digital high\/low signal to indicate motion.<\/p>\n I’m planning on mounting the on\/off button out of sight so I needed a big target to make it easy to find by touch. \u00a0I choose a momentary arcade style button<\/a>. \u00a0The control will simply toggle the lights on\/off when pressed. \u00a0I opted not to have a power switch to turn it off completely; I’ll just unplug the wall wart for the few times I’ll want to disable it.<\/p>\n The first step will be to breadboard the parts so that I can start on the software. \u00a0I’ll cover that next time.<\/p>\n","protected":false},"excerpt":{"rendered":" I had several goals in mind for the project: Light is active only at night Must have manual on\/off switch Only active if there are people present Light source not visible when the light is off I chose an Arduino Uno as the controller. \u00a0I have a few of them around and have wanted to … Continue reading Grandfather Floor Clock Interior Lighting \u2013 Design Choices<\/span> ![\"IMG_3009\"](\"http:\/\/www.streamingmeemee.com\/wp-content\/uploads\/2015\/02\/IMG_3009-300x214.jpg\")
<\/a>![\"IMG_3011\"](\"http:\/\/www.streamingmeemee.com\/wp-content\/uploads\/2015\/02\/IMG_3011-300x226.jpg\")
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