- Anybody looking for a mini-sumo circuit?I am almost finished my second mini-sumo, using Grant McKee's L293D circuit
(http://www.solarbotics.com/BEAM/default.asp?INCLUDE=L293D_minisumo.shtm)Even tho the second, a mini-track, has far better pushing ability, my wheeled junkbot (see them both in earlier versions at http://junkbots.solarbotics.com/reader_projects.htm) beats out the track every time--simply because the scoop gets under the dozer blade, lifts it up, and triggers the reverse circuit!To get away from this, I replaced the mechanical edge detectors with an optic detector and an electric switch, the MAX314 from Maxim. This is a quad CMOS SPST with two normally open and two normally closed switches (attached) This worked so well when I first breadboarded it, using LEDs to indicate the open and closed circuits, that I spent an hour playing with it just to watch it work. A matched IR LED/Phototransistor pair with a 10K resistor will detect my fingers at 3 cm and a piece of aluminum at 8 cm; these became the 'white line' detectors. However, phototransistors from Andy Pang and some IR LEDs from the Shack were able to trip the switch for paper, aluminum, and IR other reflective objects as far away as 20 cm, so this combination may wind up becoming opponent or obstacle detectors! And I kept the LED indicators as BLFNAPs (Blinking Lights For No Apparent Purpose--I like that!)My variations on Grant's circuit are also attached. It's a fun project and worth a try. No resistor values are shown on my version because I am still tweaking...Keep BEAMing and dreaming
- Tom Gray wrote:
> Anybody looking for a mini-sumo circuit?I was not yet, but planning on doing so soon. I am working thru the
Junkbots book, and sadly only to the solarollers. Thanks for the
schematics. I cannot wait to try them out, and I will post my results
when I do.
J Wolfgang Goerlich