This is the wiki page for a mini-sumo bot TP is building named 'Guard'.
Looking forward to our upcoming Mini SumoBot Competition - April 16th, 2011...
LVL1 in Louisville challenged Hive13 to join them in a Mini SumoBot competition (link needed), and from what I hear, the folks on the House Bot team put in quite a showing! This has inspired me to try to build a bot to 'play' with the House Bot. By play, I of course mean "provide as much competition as I can."
I really do intended to put some Mini Sumo background info here (really). I think the House Bot page has links to some background stuff.
For now, I'll just note that
- bot must be no larger than 10cm square
- bot must weigh no more than 500 grams
- bot must look cool
- bot must win (often)
(I added the last two for my own purposes - sue me)
- 2 Sharp 10-80cm IR range finders
- 4 Sharp 4cm IR proximity sensors
- 3 IR reflectance sensors
- 1 momentary push button (Start)
(8 digital, 2 analog)
Basically, two DC motors in a gear box driven with H-bridges. Each motor will require 3 outputs (A,B,pulse).
- Motors: Brushed DC Motor: 130-Size, 6V, 11.5kRPM, 800mA Stall
- Driver: TB6612FNG Dual Motor Driver Carrier
- Gearbox: Tamiya 70097 Twin-Motor Gearbox Kit
- Wheels: Tamiya 70111 Sports Tires
I saw somewhere that the tires and gearbox drive shafts will need to be modified to get it to fit within the 10cm bounding box. I am just going to believe that is true and hope I can manage it - shouldn't be too big of a deal.
Also, yes I know that the gearbox comes with a set of motors, but they need to be replaced to match up with the driver.
For my controller, as usual, I will be using a PIC16F688. "But wait, TP! That thing only has 12 I/O pins!" (10 sensor inputs + 6 motor outputs + ? feedback LEDs >> 12) Huh. Well, that's what they make shift registers for. I just love these little PICs too much. Irony Not Missed: adding the shift registers will take up more space that using a larger PIC with sufficient I/O pins.
Current Status - Active
- Parts ordered - prototyping of control system continues
Nov 8, 2010
I have actually been rolling this around in my head since the announcement of the LVL1 competition in Louisville. Finally got started with breadboarding the control system over the weekend. I have a box full of parts picked out on www.pololu.com that I plan to order some time late next week. Hopeful I can get this bot into the ring before the year is out.
Jan 23, 2011
So much for the plan back from November!
- Basic shift I/O of the control system functional
- Parts have been ordered and should arrive mid week!
I have been kicking around ideas for wrapping the bot with a fiberglass shell. Still a thought in progress...
Jan 24, 2011
Or maybe already Jan 25...
In anticipation of the arrival of my parts order, on Sunday night (yesterday for me, right?) I decided to screw around with the control code I wrote a couple months ago, seeing as how it's in assembly and everything. Ya know, dust off the breadboarded circuit that's been patiently waiting all this time and make sure none of the wires have been accidently pulled out (several resistors were missing, actually): and my usually flaky PIC programmer just refused to work at all. I mean... really? Now? Flaky was annoying, but at least it worked more often than not. Well, it did work sometimes :)
It's always something, isn't it? I need to get one of those "I void warranties" t-shirts...
After many, many hours of combing websites and trying every combination of (computer / OS / IDE / complier / programmer software) I could cobble together without spending any money, I decided to take the programmer apart and look at the under side (bye bye warranty seal). No dice. Not sure what I was hoping to find. ANYWAY - at some point, for reasons not quite clear to me, I took apart the ZIF connector (woah - two screws and no sticker) and upon re-assembly I found that it held the chip much tighter, and of course now works...
So, hours wasted on a loose-gripping ZIF connector... but at least now my PIC programmer fires every single time!
I am SO glad I sprang the extra 5 bucks for the two-day shipping - I can't wait!
- Did I forgot how to use the ADC in these PICs? It sure feels like it...
- Complete control system prototype
- Begin assembly
- Solder perf-board version of control system
- Ring test down at the Hive
- Tweak decision rountines
- Consider, then completely abandon, possibility of soldering a REAL circuit board
- Build chassis cover
- Kick butt in sumo ring