Robot Dialogs

A few months before Maker Faire KC a friend started working on a Mini Sumo Bot and in passing I said I could probably get a bot ready for that...well those months slipped away and two weeks prior to the faire I had no bot (and had been constantly hounded by said friend). So I did a grand total of 30 minutes of research on the internets and ordered some parts (not recommended). I ordered everything from Canada (Fingertech and Solarbotics) so I had to wait almost another week to get started. Here's the parts list I ended up with: Chassis/Motors/Tires/Line Sensors: FingerTech "Cobra" Mini-Sumo Robot 4WD Kit Motor Controller: 2x Sparkfun's Motor Driver 1A Dual TB6612FNG Micro-controller: Arduino Pro Mini 328 - 5V Proximity Sensors: BittyBot 3-Way Object Sensor Battery: Venom 10C 2S 1250mAh 7.4V LiPO Line Sensors (Included w/ chassis kit): Phototransistor - QRD1114 More Stats below...  The first thing I did was construct the BittyBoty 3-Way Object Se...

Quick post of some old video of Spin Cycle ...just now got around to uploading it.

This post is a retrospective look at the first robot I built solely for myself (back in 2008). I had only helped build one robot before this. It's clear I got a very late start into robotics. Although school did prepare me formally to dive right in, I wish I had been more focused on it when I was younger, I would have really flourished in college. This robot was designed mostly on a whim, but has turned out to be a nice solid prototype, and it is very useful for testing sensors and AVR code... The Parts List: Aluminum Chassis, Motor Mounts & Tire hubs - Machined while I was still at RIT when I had access to their machine shop. No original designs are available, I just went in and used what scrap I could find...I'd be embarrassed by providing the true measurements :). Stepper Motors - From Sparkfun ...I may replace these some day with cheaper gear motors so I can use these steppers in a CNC/Drill Press. EasyDriver Stepper Motor Driver - Also from Sparkfun...sim...

Well unfortunately I was the only person to enter the competition officially, so it was canceled . To appease the robot gods' thirst for robotic mayhem Sparkfun morphed the events this weekend into a robot building/hacking/soccer match shindig . Making the 8 hr drive (one-way) was totally worth it even without the competition. I was able to demo "Spin Cycle" to those attending. Most of the day was spent on a class detailing the steps necessary to build an Ardubot for several people who had never made their own robot before. I've been a loyal customer and follower of Sparkfun.com for at least 3 years. It was great to finally meet some of the people behind the handles . I'm frazzled so no more text. Here is a video of my bot in action, and some pics from the trip. "Spin Cycle" The view from not even a mile away from SparkFun's building. (So...jealous) The fancy sign. Some nifty robot tracking (webcam+IR LEDs+ projector+codes=awesome). Th...

Time for the code... The software portion of this robot was fairly straight forward compared to the electrical and hardware designs. I had several previous robots and experiences to pull from when writing the code. As a result the code is very clean and well documented. There are two languages required to understand the code: JAVA and C ( AVR Libc to be precise). JAVA: I used JAVA to create a user interface which would take keyboard input and translate it into serial commands. The UI is very simple. It uses a KeyListener (which is added to all visible components of the UI) to pick up key strokes from the user. When a key is "typed" a string of characters is sent via GiovynetSerialPort1.3 to the XBee Module attached to the PC. The XBee acts a transparent serial cable with the XBee on the robot as the other end of the cable. Any serial data coming from the robot is displayed in the text area... I used Giovynet's serial port library for two reasons; first, Sun (JAVA)...

Well I managed to get all the parts purchased, designed and/or fabricated before the weekend of the event. As is often the case with project like this, my designs changed as I searched for parts. You will see below the final designs created in SketchUp (they really are final, based on the bot I took this weekend). I put a great deal of effort into getting exact dimensions in every place I could. In fact the only blatant differences between the drawings and the real robot are in the purchased parts(drill and batteries) which have too many curves to replicate. SketchUp Model I'm pretty certain no one will want to duplicate this exact design (anyone capable would probably find that boring) ; however, some of the components may be useful. The motors , motor drivers , wheels and hubs are all precisely measured, and could easily be copied into another drawing. I've decided on a name: "Spin Cycle" (a suggestion from my older brother). The name stems directly from the...

Well it seems that every attempt I make to reduce cost on this robot just comes back to bite me in the end. I think I've learned my lesson...buy new shit and don't try to cut corners. I'm referring to the motors and the motor controller... While investigations into the motor controller resulted in a good design (based on that of the Open Source Motor Controller ) the cost and time needed is prohibitive at least for the motors I'm going to use. So I've ended up purchasing two 9A motor controllers (one for each drive motor). They work very well for these motors (they are way bigger than necessary). One issue came up when I mounted these to the chassis though... Two of the controller's mounting holes are attached to OUT A on the PCB as you can see in the picture. So when I bolted the things to the bot and started using them, a full 15V was applied to the chassis. This burnt out two cheap sensors (fortunately I had enough replacements on hand) and it wouldn't l...

Update: This circuit doesn't work (thanks Sparkfun Forums folks) revised version will be in next post. So I've worked out the motor controller circuit I'll be using. I've ordered the components too. Hopefully when I get them it will work as planned without too much modification. Or the Google Doc The major components: Power MOSFET NPN Switching Transistors Opto-isolator/Photocoupler It's less complicated than the circuit makes it look... It's really 4 identical circuits (which I show in lower part of schematic) attached to the MOSFETs of an H bridge. The optoisolators ( PS2501 ) are also a single package so wiring won't be as complicated either. Please feel free to comment or suggest changes... I've never built a circuit for high voltage/current motors like this before and could really use another set of eyes on this. (Especially if it looks correct, I need positive reinforcement as much as criticism :)

Okay so the main reason for this new website/blog (for the time being) is to chronicle the build of a super sumo style robot for Sparkfun's RoboJoust competition on December 6, 2009. As I'm currently at my childhood home in nowhere's-ville Kansas I'm near enough to the competition site (Boulder, CO) to actually participate. I'm looking forward to touring Sparkfun's building and meet other robotics folks. Info on the competition is here . The basic idea is to have two robots start at opposite ends of the track (below) , meet in the middle, undergo epic battle conditions and finally limp to the opponents starting point. First prize for the event is $100 so I'm considering that to be my budget for materials. With that budget in mind I'll be trying to locate old cordless drill motors (for locomotion and weaponization). For now I'm still sketching and brain storming, but due to the budget I'm going to be keeping things very simple: heavy - (battery/...