Multiple BlinkM MaxM Blasters on one Master

BlinkM MaxMs will be back in stock soon. Over on our GetSatisfaction area, there’s a question on how to use multiple BlinkM MaxM “Blaster” LED boards with one MaxM “Master” driver board. It’s possible and only just a little tricky. The Blaster board is powered by the 5V voltage regulator built-in to the Master board. That regulator is designed to power just one Master and one Blaster. If you try to drive multiple Blasters with it, it might work, but we don’t recommended it and could blow up your Master board.

Instead, it’s better to drive the MaxM with an external 5VDC power supply. This isn’t officially within the operating range of input voltage for the Master, but for this application it’s okay. To drive multiple Blasters, you then run that external 5VDC supply, available from the “V+” socket to the “5V” pin of each Blaster. And do not connect the Master’s “5V” to anything. Here’s a wiring diagram (click to enlarge):

maxm_multi_blasters

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permalink April 12th, 2009 | Category: blinkm | 7 comments

Tiny Servos as Continuous Rotation Gearmotors

I’ve been exploring various types of gearmotors. DC motors by themselves spin too fast and have low torque. Gearmotors are motors with a gearbox that slows down the high speed of the motor and produces higher torque. Most gearmotors are pretty expensive though. I want a really cheap, almost throw-away, source of gearmotors. It turns out cheap servos can be made into continuous rotation gearmotors.

Modding servos for continuous rotation is not a new hack. You can find many examples of it. You can even buy a nice continuous servo made by Parallax. But I wanted a micro servo version. I’ve been getting cheap servo motors from Hobby City, and they have several super-tiny servos for less than $4. The ones I use here are the Hextronic HXT500 available for $3.49 each.

Here’s how to modify one of those servos to make it into a tiny little gearmotor.
Continue reading Tiny Servos as Continuous Rotation Gearmotors

permalink April 11th, 2009 | Category: arduino, hardware-hacking, toys | 34 comments