Friday, December 30, 2016

BoB's mouth prototyped

So the standard 3D print for the BoB robot comes with eight 3mm holes for the robot's mouth.  I've got some flat topped 3mm leds that go perfectly in these holes, so I figured that's what I'd do with them.  I want to be able to make patterns on the array and so need to be able to individually light each led.  Doing this directly with the Arduino eats up all the available I/O, and doesn't leave any room for expansion, so I got some MCP23008 I/O expander chips.  I figured I'd be making a custom board to handle the leds, so I ordered the SOIC package from Digikey.  I got a chance to work with them today and using an Adafruit SMT breakout pcb for SOIC I breadboarded the circuit and used the Adafruit supplied MCP23008 library to write some Larson scanner software.

The next step is to design and fabricate a custom board to fit the chip, leds, resistors, and all the connections into BoB's head.  After that he gets "eyes" with an ultrasonic sensor.

Tuesday, December 27, 2016

Newest build

We are visiting family over the holidays, and my father in law has a collection of some pretty nice tools.  I typically come with a project in mind so I have something to do while we're here, and this is the project for this trip.  It's a custom designed RC flight box with space for my transmitter, parts, tools, batteries, and propellers.  I didn't want to spend a lot of effort on it, not knowing how I'd like the design, so the construction is dead simple 1/2 inch ply wood with glue and nailed butt joints.  As you can see I still need a dowel for the handle.

Saturday, December 24, 2016

Air boat on ice

Last summer I built an airboat out of pink insulation foam and scrap 1/8 plywood. With a -2 degree wind chill the pond is kind of "stiff" so I took the boat out onto the ice.  Turns out it runs pretty fast, but not really in a straight line for very long!

Newest Robot

On black Friday I got a great deal on a 3D printer.  One robot I've always liked that requires 3D printing is a BoB.  The design files for the mechanics are available on Thingiverse.  So not long after I got my printer set up and had a couple of prints under my belt my BoB came out.  Four 9-gram servos and some small screws later and the mechanics were done.  Everything went together without a hitch.

Then I added an Arduino Pro Mini, a boost regulator, a battery pack, a switch, and about an hour of programming.

I've got the 3mm leds for the mouth and the ultra-sonic sensor for the eyes, adding them is next, but that will have to wait until I get home from Christmas travels.

Thursday, December 1, 2016

Testing my new Mobius action camera

I got a Mobius action camera for my birthday the other day.  I plan to use it mostly to flying video, but recently the weather has not cooperated.  Wanting to see it work, I mounted it on Clifford the little red robot and shot some video from his point of view.

Monday, November 21, 2016

Clifford the little red robot has new code

When I build robots I typically concentrate on the hardware and only write enough code to test the hardware works as I'd like.  I initially built this robot about 4-5 years ago, and he never really did anything interesting because I never invested much time in the software.

In the past few weeks I've spent some time programming the little guy, and have him to a state I can show to folks...

I have the motors, wheel encoders, servo, and ultrasonic distance sensor all working in a pretty well integrated behavior.  I still have some more work to do to smooth out the motion.  He moves in discrete steps now because the wheel encoders don't handle overshoot and I can't let him build up much momentum.

He's controlled with a Microchip PIC16F684 micro-controller programmed in assembly language with Microchip's MPLABX IDE.  I designed, etched, and built the board myself.  His body was purchased from Sparkfun.

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.