Author Archives: Jim

Random colors with RGB LED

Posted on April 5, 2012 by Jim

Partly trying to have something fun to demo and get juices flowing for the kids in the new STEM Explorer Post 314 we’re trying to start up, I thought I’d try to make a smoothly randomly color changing RGB LED … Continue reading →

Posted in RGB LED stuff | Leave a comment

Major progress on LED display

Posted on March 30, 2012 by Jim

After another evening at W88, there’s some good progress on the display.  First, there are four boards running in the display that I didn’t have to make!  I did etch them, but Bill and Karl ground them down to size … Continue reading →

Posted in Scrolling LED, Workshop 88 Stuff | 1 Comment

6 more latch boards for scrolling LED display

Posted on March 21, 2012 by Jim

We have 6 more (working!) boards in the display.  The goals were to see whether it looked good enough to continue the project and to get scrolling code working a little better.  Made only partial progress on both. I tested … Continue reading →

Posted in Scrolling LED | 1 Comment

Battery tab welder has foot pedal and charger cutoff

Posted on March 17, 2012 by Jim

Faced with a potentially large number of welds for rebuilding a DeWalt battery, I finally integrated two improvements that have been waiting in the wings:  a MOSFET charger disconnect and a foot pedal to disconnect the charger and fire the … Continue reading →

Posted in Battery Tab Welder | 1 Comment

DeWalt battery rebuild

Posted on March 17, 2012 by Jim

What better birthday gift for my friend Ed than a handmade rebuilt 18V DeWalt battery made from recycled sub-C cells?  OK, especially when he provided 2 of the old packs I scavenged from. In addition to Ed’s donations, Mike D … Continue reading →

Posted in Battery Rebuilding | 2 Comments

Making your own printed circuit boards at Maker Faire

Posted on March 13, 2012 by Jim

I’ll be running a booth at Maker Faire Northside Chicago April 21, 2012.  This post will provide a little info about it. Rats.  I’m out of town that weekend.  I just wrote Christina to cancel the booth I just submitted … Continue reading →

Posted in PCB Etching | Leave a comment

Eric fixed the bad board!

Posted on March 9, 2012 by Jim

At the space Thursday evening 3/8 I hauled the display out to see if I could address what looked like lack of +5 to the 4th latch board from left.  I reheated the +5V bus to that board, but the … Continue reading →

Posted in Scrolling LED | 1 Comment

First “production” recorder

Posted on March 3, 2012 by Jim

A dance weekend finally inspired me to actually get the first model of the “final” design put together.  It’s almost all SMT (including a thru hole 3914 with its legs bent under), so I soldered most of the components on … Continue reading →

Posted in Recording preamp/limiter | Leave a comment

Balloon + coffee + vacuum gripper

Posted on February 27, 2012 by Jim

I’d watched with interest some clips of using a vacuum to “solidify” dry coffee grounds in a balloon to effect a robotic gripper, but was finally inspired to actually try to make one as an assistant counselor for a Robotics … Continue reading →

Posted in Robotics | 6 Comments

Bluetooth module breakout

Posted on February 23, 2012 by Jim

This is just a quickie to provide a way to connect to a Bluetooth module for Russ’ chording keyboard.  I found a datasheet and an Eagle lib with the footprint.  Unfortunately the pads didn’t provide enough area outside the “half … Continue reading →

Posted in Miscellaneous, Workshop 88 Stuff | 3 Comments