Journal buffer-overflowed's Journal: Wii DIY - Wireless Sensor Bar. 4
So, we have a projector right, which means the Wii sensor bar cable is wayyyy too short.
New cables/extenders don't come out until January. Unacceptable says I! But unlike Tycho over at Penny Arcade, I decided to do something about it. Little digging into the Wii reveals that all the Wii provides to the Sensor Bar is power. The Warnings in the manual and various info online, plus the fact that calibration picks up tungsten bulbs, means we know it's IR, and the sensor is in the Remote. A few pics of it taken apart and boom, know how it works. Junior High-School shop class level project.
So, we need a new sensor bar that's independant from the Wii, and i don't want to have to change batteries or deal with any of that, so I browse Radio Shack's online store for IR sensors. Find a 1.2V 100mA High-Power IR LED they sell. The sensor bar pics I've seen show 2 sets of 3 LEDs, seperated by a foot. So we need 6 LEDs. Our power supply needs to be able to supply 600mA. We dig around in the boxes of geekdom, where all old AC-DC converters go to rot and find a 5.7W 1000mA AC-DC Adapter. Score!
So, now it's just a question of figuring out how much resistance we need. It's an easy formula, R = (V - FV)/FC in Ohms(V is the adapter voltage, FV is the LED, FC is the mA in amps). Quick calc R = (5.7 - 1.2) /
One hour later, we have a working sensor bar that actually works better than the stock one, and isn't tied to the console. Awesome. Total cost: $10.
So for anyone else complaining about this, it's not too hard to whip one up. Of course my electronics knowledge isn't so hot, but the thing barely gets warm so far(only been 3 hours though), and it works like a dream.
I'm not sure I follow your math (Score:2)
If you have connected the LEDs in series, and you are applying 1.2 V to each, you would need a power supply of at least 7.2V. However, if you wired them in parallel, you would be drawing 600ma at 1.2V. Therefore your resistor network would need to be R=V/I=4.5/.6=7.5 Ohms.
From your description, it sounds like you are actually delivering about 50mA to the diodes, running them just a little above their turn-on point of roughly 0.6V.
Re: (Score:1)
Re: (Score:1)
So it's parallel, + -> Resistors -> LEDs -> Resistors -> -. I'm going to redo it, I just wanted to toss a proof of concept together, so doing it properly would be nice.
well (Score:2)
i watched the video that pa linked on youtube about how the sensor bar works-- pretty cool.