ProtoCylon: Tell Me How You Feel

By Bobby Neal Winters

I’ve discovered that it’s been exactly two months to the day since I’ve blogged about my robots. There is an alphabet of reasons: HLC, PSU in PY, and NALM.  This is to day we had an accreditation visit at the university in early March; I took a trip to Paraguay in Mid-March; then in late March and early April I’ve been mowing the lawn and watching my beautiful, youngest daughter play soccer on the weekends. While I could whine a little about getting older and not bouncing back from the Paraguay trip as quickly as I would’ve liked, I will skip that.

Suffice it to say that this weekend, my beautiful, youngest daughter played soccer on Friday night; I mowed Saturday morning; then Saturday afternoon I began to play, er, work seriously on my robot once more. I decided I needed to know when it thought it was stuck so I put a couple of LEDs in the system to let me know what state it was in: trapped or not trapped.  I did this and promptly the robot ceased to function correctly.  

The robot is supposed to go straight until it encounters an object.  When it encounters an object, it goes into a trapped state and accesses its getFree function.  In its get free function, it turns alternately left and right in a struggle to get free.  

After I installed my upgrades, this no longer happened.  It seemed to simple act as if it were trapped all the time.  

I was confused.

I know what you are thinking: When I put in the LEDs, I messed something up.  That was the first thing I thought, so I inspected the program to look for conflicts and found none. (Remember this sentence verbatim because its important.)  Having dealt with the programming issues, I began to inspect my motor shield.  This is the special board I’ve got my motors hooked to the Arduino through.  I did a bit of experimenting, including changing how the motors were hooked to the motor shield.

This experimentation determined that the motors were both fine, but there seemed to be a problem with electrical connections for the right wheel motor.  I suspected a short.  I thought--briefly--about desoldering it to fix it.  I thought--longer--about buying a new motor shield.  Then today as I was playing, er, working on it seriously, I read the top of the motor shield.  It is quite an intricate little device with places to hoot in servos and what have you.

I was looking it over and saw that by Pin 9, to which I had hooked an LED, there was a label that read Brake A.  When I was sending current to Pin 9 to light that LED, I was applying Brake A which was (drum roll please) the right side. I moved the LED and the problem was solved.

It was a little thing, but it gave me such a RUSH!

It’s that childlike feeling of discovery. I hope I never lose it.

An Interlude: Confronting Demons and Skeletons

By Bobby Winters
I may have shared with you before the brain block I have with regard to soldering.  When I was a kid, I’d gotten a computer kit that required soldering.  I made a mess of it and it wouldn’t work. It cost a lot of money, and we didn’t have all that much.  So, in my shame, I put it aside.
Since I’ve begun playing with microcontrollers, it’s become clear to me that beyond a certain point I will need to know how to solder.  Breadboards are nice, but anything that’s not going to be taken apart eventually will need to be soldered together.  I’ve taken to a program of learning the manly skill of soldering.  I’ve confronted the soldering demon.
I will never be an artist.  Heck, I may never actually solder anything that works.  But I am beyond the “Oh my gosh, what a mess” stage.  It boils down to those three words people have been telling me all my life: “Take your time!” Yes, that’s it.  That’s the secret.  One must decide that soldering is a thing that one must do and then set out the preparations to do it.  
The first thing is to prepare a place.  You’ve got to have a place to do your work.  The second is to have all of your materials around you.  You need your soldering iron, its stand, a little wet sponge to clean your tip on, and--this helped me a lot--a desoldering iron complete with attached desoldering bulb.  I always do a better job writing when I have an eraser, so it figures I do a better job soldering when I have a desoldering iron.
All of that having been said, I’ve not been able to solder a heat sensor to the pc board yet.  I think that I’m frying them.  I hook them to my thermometer program and they read -196.6. I tried three times and got this result three times with three different ruined sensors--and I’ve tried using a alligator clip as a heat sink.  In the world of digital thermal sensors, I am now known as He-who-brings-hot-death.  I am now looking for conductive glue on Amazon.
On other news, I’ve gotten a skeleton for my ProtoCylon.  There’s a picture below.  My experience in opening the box and thinking about putting it together made me think of building the pyramids.  I knew it could be done, but thousands might die in the process. There were parts--nuts, bolts, wheels, motors, plates--but no directions.  I have got something screwed--such a versatile word--together, but it was interesting.  I suppose they thought it would be more interesting without the directions.