Let's Make Robots!

Sharp IR and voltage drops in large systems

I don't know why I decided to put a Sharp IR (GP2Y0A21) in K-9.  Probably because it's smaller than the HC-SR04 that I'm so much more used to.  In any case, I got a general system assembled and decided to test it using essentially the same branching that I used on Maus.  It seems to go into its obstacle avoidance routine at random.  It definitely reacts when it "sees" something, but also often when there's nothing in front of it.  What I'm wondering is could the "Analogness" of the sensor be what's killing me?

Hakko 888 review (Do I really need to?)

This is more of a follow-up to my review of the "9936" soldering iron that disappointed me so badly in my last blog entry.  Let me begin by saying that the problem with the iPad is that it makes it way to easy to buy things while you're taking a crap.

Linux voice recognition

Allright Tux lovers-I'm looking for a GNU voice recognition system that works as well as Mac's (or Siri, I guess.) Wifi dependent or embedded, whichever, for a SBC (Beagle/Raspberry/Panda, you get the idea. Any suggestions?

9936 Soldering Iron Review

I kind of got on the "I need a better iron" bandwagon and picked out this one off of eBay for around US $35.00:

It's basically a Hakko/Aoyue/Atten style 907 pencil and an electronic control unit somewhat like what Gareth reviewed a whiile ago.  This has a built-in AC line and the read out is oriented the other way.

Conductive rubber as a sensor

Found this recipe at instructables: http://www.instructables.com/id/Conductive-Rubber-Make-Touch-Sensitive-Robot-Skin/ Has anyone played with this as a sensor? Any pointers or insights? I don't really want to make a "skin" but an odd shaped bumper or two might be useful on an open ADC pin-think a custom FSR...
Navigates via sound (as a contact switch) or IR for obstacle avoidance
Using a
A while back, JAX and I got to chatting about our first robots.  Mine was a "Movit Peppy Mouse:" Read more

More H-bridge drama

I'm playing with the idea of a BeagleBone based bot. GPIO on that board is all 3.3v and there aren't a lot of ready made "capes" (the BeagleBone version of a shield because that's what Underdog wore.) I've had the best luck with L298 based shields (way more amperage than even a 754410) so looked up the data sheet: http://content.solarbotics.com/products/datasheets/sgs_l298_motor_driver_ic.pdf The way I'm reading this is that a 3.3v signal would be just dandy-even a 1.8 v should show up as a logic high.

"How It's Made" for Us!

I thought this was pretty cool.  A weekend worth of bringing together the parts for Adafruit's Photoduino compiled into a 3 minute music video.


I think its for "trick photography."

More L293 Problems-Any Ideas?

Here's the idea-to use the L293 as a one direction speed control with PWM on the enable.  Theoretically I could do something like this:

With a pull-up and a pull-down to the logic pins respectively to keep one high and one low.  The problem is when I tried it, this happened:

The motor never moved and the chip and the board are one now, I'm afraid.  Luckilly I bought about 8 of these.