Thursday, July 7, 2016

Long time no post - making new boards

For the past couple years I've been building and flying RC airplanes.  Recently I've been thinking about getting into night flying.  Doing so would take lots of LEDs on a plane, so I've been building an LED driver circuit.  I just got the parts in the mail today and put together the driver above.  It will drive 11 different led circuits and is the size of a 24 pin 0.6 inch DIP.  I chemically etched the board using toner transfer and hand soldered all the SMD parts.  The Eagle files are up on Google drive if you're interested.

Monday, December 30, 2013

Holiday Hacking Bender - Day 6 - Project 2

I've been thinking about this project for a long time.  Many years ago (mid to late nineties) I took a lot art classes just for fun.  I explored a lot of media including drawing, ceramics, photography (we used a thing called "film" back then), but my favorite was jewelry.  I did mostly fabrication, and specialized in lockets and other enclosures.  One enclosure I've always been fascinated by is the reliquary. I'm not sure of the Webster's definition, but I see them as a small secure places to keep something ancient and treasured.  Now, one of the things I've always held with that group of ancient and treasured objects are stones containing carved petroglyphs.  I'm thinking a stone bearing a personal totem encased in a wearable reliquary would be a brilliant piece of jewelry.

Jump forward to today, or at least the recent past, when I finish putting my ShapeOko together, and the first thing that occurs to me is "I wonder if I can get it to carve petroglyphs?".  Today's project is the beginning of that exploration. I don't want the glyphs to look machined, so I'm attempting to build a vibratory hammer type thing.  This version is a simple electromagnet with a hardened steel plunger retracted with a rubber band.  After playing with this today, I'm not sure I can get this design to go fast enough.  I might need to go to active position control of the plunger.  Right now the control circuit is a 555 driving a TIP120 - pretty simple.

Holiday Hacking Bender - Day 6 - Project 1

The first project of the day was pretty simple, but meant a lot.  A couple of months ago my son Nathan spent his allowance on a Raspberry Pi.  He mostly got it because he heard he could learn to program Minecraft on it, but he's also into Snap-Circuits, and other geek stuff, so for Christmas I got him a pi case, cobbler, and getting started book from Adafruit.  He also got his own soldering kit, so this morning I helped him through putting together his cobbler and getting his pi into the case.  The he wrote some python to make Das Blinken Lite Machine.

Holiday Hacking Bender - Day 5

Not Such a Good Day

I had planned another wood working project for the day, but couldn't stand the idea of doing it with the state my shop was in.  I spent a great deal of the day cleaning and organizing the shop, and ran out of energy before I got anything made.  Yes - things were quite the mess, and still not completely straight.  I need to build some tool cabinets before I'll be able to organize everything the way I'd like.  I will make up for the lapse by making two projects today, day six.

Saturday, December 28, 2013

Holiday Hacking Bender - Day 4

What you see is the result of today's efforts from the electronics department. Things went pretty well there, and I feel pretty good about the build. The brown board on the left is obviously an Arduino clone. I build the little "micro shield" to provide a robust plug in for an I2C interface. The little green board on the right holds an MLX90614ESF-AAA Infrared Temperature Sensor. It's connected to the micro shield with an upcycled USB cable, so the sensor can be some distance from the Arduino.  Right now it's just running an example sketch I shamelessly stole from  Then, not being satisfied with stealing only a little I went out to an Australian Robotics site I found through ThingSpeak and stole some more code to post the temperature data to a channel on ThingSpeak.

So, the electronics department delivered, and the software department, after having been abused by assembly language programming all day yesterday, lost all sense of moral direction and stole everything, so in a way they delivered.  The manufacturing guys though, just couldn't pull it off today.  I had intended to build a desk lamp like articulated arm to hold the temperature sensor in varying places and orientations.  I got the design done, the g-code is even available, but my CNC just would not cut the parts.  After two attempts, each of which took more than an hour of cutting time. I decided to just give up.  I think the machine has a problem with static build up or is haunted, because on longer cuts it just intermittently looses its mind.

Anyway, that's all for day four, see you again tomorrow.

Friday, December 27, 2013

Holiday Hacking Bender - Day Three

Today was a lot more fun than yesterday.  I installed new sensors and software on my little red robot.  I read a definition for what a robot is the other day that I really liked more than any other definition I've ever heard.  The definition didn't have anything to do with technology or autonomy, it simply said that any machine with enough personality to be given it's own name is a robot.  I care for and watch over many small machines others might call robots, but only a select few have earned names.

I bought this red magician chassis just to see what a fifteen dollar robot chassis would look like.  I'm kind of stuck on the red now, and I keep tinkering with the little guy trying to coax something really endearing out of him.  I made some progress today, and with the new sensors opened some new paths for him.  Maybe someday he'll earn a name.

Thursday, December 26, 2013

Holiday Hacking Bender - Day 2

For today's project, I wanted to get up from my electronics desk, and get into the wood shop.  My wife has been asking for a jewelry box, so I decided to try to do it in a single day using a technique called a "band saw box".  This technique takes all the complex design and joinery out of building a box with drawers.  I drew my design free hand directly on the wood, then made all the cuts on my band saw, again free hand.
Even though it's a lot easier than flat panel construction, it's still wood working, and demands a certain precision.  I took some shortcuts here and there and paid for it later when I screwed up the bottom half of the box so badly I had to cut it off and throw it away.  Yes, the original design had four drawers.  I made the decision to take this drastic step about 5:00 pm this evening, and I was about ready to bag the whole project and call today a fail.  I'm glad I didn't give up, because even as it is the box brought a smile to my wife's face.  Although her first comment was "You do realize it's not big enough, right?"
Well, that's all for tonight.  Tomorrow I pick the soldering iron back up.