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Topic: Warning! One Million Ohms (Read 13510 times) previous topic - next topic


Maybe you could just have a couple of  ultra-brite diodes blinking and just say WARNING INFA-VIOLET RADIATION! or WARNING ULTRA-RED RADIATION!

Jack Christensen

I think if I were to make a couple mods for wearability, they'd be a slightly smaller size, a square of bare tinned space so the solder mask doesn't have to be sanded off for the clip, and a coin cell holder on the back, as the battery pack is a problem when you're wearing it. I'm just going to glue a coin cell holder to the back of this one and wire it in. But the joy of an open source design is, I need some more practice with Eagle. I can fire up the open files that are provided, and make those changes.

Sounds like a "Million Ohms Pro Mini" version ;)  Let us know if you do it!


Great kit.  I'd like to see a capacitive input connected to the Mega-Ohm so it "activates" when someone touches it. And maybe a piezo for some "shocking" sound effects.



Just wanted to post a little update. I think I mentioned my plan to go with a more wearable battery pack for this thing. I picked up a USB LiPo charger from Tindie with a nice JST connector on it. Works great with a LiPo pack I bought from SparkFun, but that pack was meant for a different project. So I dug around in my junk drawer and found an old bluetooth headset that never really worked right, and had been sitting around for at least 3 years. I pried it open and found a nice small LiPo pack inside. Some more digging in my junk drawer and I found some JST connectors at the end of some vibration motors from an old XBox controller that had died. Combine the JST pigtails with this little battery pack, and I was able to charge it with the USB charger. I swapped out the screw terminal on the Million Ohms board with a JST connector (polarity was backwards for the right angle connector I had, so I had to bend the pins all the way over and install it upside down. I was surprised they put up with it!). Conveniently enough, the LiPo pack had some doublestick tape on it that was still good, so I just stuck it to the back of the board and plugged it in. The extra voltage did wonders for the blue LED's. They're insanely bright now. :) Real attention grabber. Not sure of the capacity of this battery, maybe 150mAh?  But this unit seems to sleep when it's not blinking so I suspect the battery life will just fine.
Here are some pictures:

Jack Christensen

Sweet, thanks for the update. I'd seen those small LiPos and they look pretty nice. So you use the same charger that you would have for the bluetooth headset?


Maybe it should warn: "1 Megavolt / per Ampere" ;)
Check out my experiments http://blog.blinkenlight.net


I'm using the LiPoNano from Tindie to charge it (and my other LiPo packs).


How long will the batteries last? (2xAA) +/- ?

Jack Christensen

How long will the batteries last? (2xAA) +/- ?

Of course it depends on how much use it gets. The circuit goes into power-down mode after five minutes, but I'd guess at least several months with frequent use, could be a year or more with less use.  With the power-down logic disabled, i.e. running 7x24, it will run 2-3 weeks on a fresh pair of alkaline cells. (The power-down logic can be disabled by holding the button down while inserting the batteries.)

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