Status Update 4/25
Long Overdue Update
I have been meaning to update the blog for several days now, and I had a huge, long winded post in the works going over my plans for what kind of parts I was going to buy, etc. It was just far too rambling and not really relevant, so I am just going to scrap it. Mostly because…
Shiny new parts have arrived!
My next step is to connect both motors to the lobotomized hexbug, replacing it’s old control system with the oh-so-sexeh Arduino. After talking to as many people who would listen to me about it, I got me one of these bad boys: Motor Driver 1A Dual TB6612FNG
I chose this particular model because a) it is small b) it seems to offer all the features I need to control the turning and the motion of the robot. From what I understand, it is just a neat wrapper for a pair of H-Bridges and some simple protection features so you don’t fry your board with Back EMF edit – This turned out to not be the best part for the job. I ended up having to buy a different, much easier to use one instead. See this post.
I also got a simple short-distance Sharp range finder which I will use to let the robot avoid obstacles. I will post more on that once I get into it a bit more, but it seems like your basic analog sensor, so I hope it will not be too hard to get it working. All I want to do with it is get the robot to avoid obstacles as it moves around. It should be fun, as it seems that once I get there, it is much more about programming and less about the hardware.
Oh Power Supply – Why are ye so tricky?!
My next challenge right now is power. I have had a huge amount of support from my friend Theodore at Tomorrow Lab. As of now I want to be able to power 2 micro motors, a motor driver logic board, and a IR rangefinder with one 9V battery attached to the 3.3v and the 5v power supplies that the Uno has to offer. From what I understand, doing it wrong can destroy the Arduino, and that would make me a saaaaad panda. I am hoping to start by powering the logic board on the driver and the rangefinder with the 5v and the two motors with teh 3.3v (which from what I understand they will split between the two motors – Anyone know if this is wrong? Holla in the comments!). If that works, but the 3.3 turns into 1.6v to each motor (which would be super wimpy) then I will switch the power supplies so that the motors share the 5v with the rangefinder and power the logic alone with the 3.3v. Alternately, I may wire up the motors so that they take their power from their own dedicated power supply, which could be just a coin cell.
I have some photos from my tests on the motors which I will upload soon (I just have to do a little retouching/resizing).
Getting it all together
I have got myself a teeny breadboard and a ProtoShield for the arduino which I will use to actually hook all this stuff up – I hope to solder that thing together tonight or tomorrow night!