Let's Make Robots!

elp-hay me on my sensor network

Hair brained plans galore! I am planning on flooding my house with environmental sensors. Temperature for starters. All over the place. And of course I want my readings to be gathered on a central machine. Live. So, no data logging on separate memory chips. I need some sort of network. With wires and stuff, because I do not trust the airwaves for this sort of thing. Also, I am a cheap skate.

Spam avoidance

You may not remember from way back when, but since March 2010 new members have to pass a tiny little quiz before we will allow them onto LMR. The main reason for this was the onslaught of spam on the site.

And it helped a lot! The number of spammers that get through have dropped dramatically! I guess they choose to move along and pester some other poor blogger.

Xbee Live Conference

Call for conference guests

Who is interested in the upcoming Skype Conference on the advanced features of Xbees? The conference will be broadcast as a special live episode of the video (help-) show.

We are looking for a suitable and practical time slot. Hopefully some time this weekend. Can I hear some suggestions?

picaxe 08M and servo/servopos - frequency problems?

Is this true? I am a total newb on the 08M, so the manual is full of surprises to me.

It states: "The servo command will function correctly at 4MHz on all parts (except X2, which only function at 8 or 32MHz).  16MHz  is also supported on X1 parts. No other frequency will work correctly".

Does that mean that I will have to underclock my 08M from 8 MHz to 4 MHz in order to use the servo command?

Xbee conference notes

Gareth, David, Glen, Chris and I discussed Xbee radio modems. Here are some notes I took.

Watch part I  here.  Watch part II here.

TAG all your Xbee related content with the tag "xbee", please.


CtC Bingo

For the upcoming episode of the Friday night video show, I propose a game of "CtC Bingo". We create bingo cards with up to 25 typical "Chrisisms". Whenever you hear on of them being used live in the show, you cross it off your card. When you crossed off five in a row, you shout BINGO.

Prizes to be determined.

PCB design software (EDA) for Linux users

I am using my Ubuntu laptop more and more often. And today I found myself wanting to throw together a simple schematic for posting on LMR. So I needed to find a CAD program for that. One that works on Linux.

Shouting in the shoutbox is fun and all, but valuable info gets lost. So please everyone, use this thread to post your experiences and recommendations.

So far I discovered in my Ubuntu (10.04) repository:

google them for links or downloads. I will post my experiences with them here as I gather them.

SparkFun goes bonkers - no even more bonkerers than usual

Sparkfun is having a new contest: "Antimov".

The robot that violates two out of three Laws of Robotics in the most spectacular and creative and funny and effective way wins $300.

picaxe 28x1 input/output direction


I am using a picaxe 28x1 and I am developing new code like crazy. In one of my sub routines, I need to reconfigure one of the input pins (pin 7 in port C) to output mode. Then pull it low. Then wait a bit. Then make it high impedance again. That is to say, it must become an input again.

Suicidal Picaxe Program

Here's what happens on a Picaxe 28x1 in a project board when you connect pin C.7 to the Reset pin. Check out areas F and H in this photo.

The reset function in a Pic(axe) is made so that when it is pulled low, the chip resets. An on-board 4700 Ω resistor keeps the pin high during normal operation. The little button pulls it down.

This Picaxe really is stuck in a moment and refuses to believe: