Robot Dialogs

The Maker Faire has come and gone and was a pretty big success. We had a news crew in the morning and then a whole slew of people showed up. I had the RC Nerf Turret and other robots on display. It was a long day with a lot of interested people and a ton of kids. The turret got most of the face time, even got on the news and a mention on the Make Magazine blog . There's a bunch of pictures here and here . I bought a LoL Sheild and Diavolino and got it up and running this week. I'm pausing progress on the Gameboy project so I can fix and upgrade the software in the turret before I take it into the office. Note to anyone reading: We are going to have another Maker Faire next year. We don't know if it will be mini or full sized. It all depends on how many exhibitors we get...but... WE NEED MORE ARTISTS . A Maker Faire shouldn't be confused with science fairs (which this one was...far too often for our liking). So carpenters, welders, sculptors, photographers, n...

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

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 :)

I've visited about 15 local hardware/hobby/auto parts/tool stores in the last 3-4 day looking for ideas and ways to turn these drill motors into drive motors for the robot. I've also logged about 8 hours of research into gears, gear types, gear ratios, and speed/torque conversions. I've decided to scrap the idea of using these motors as drive motors. The two main reasons are cost and unknowns. It costs as much to buy geared motors as it does to buy the gears to get these working. These motors are terrible as far as documentation goes. There's no way to find out their intended voltages, current draw, stall current stall torque and on and on... Because of this I don't know how far they need to be geared down. It would take some trial and error at my cost. I don't have the time or funds to do it. The other reason is complexity...It would take a fair amount of machining to create mounts for all the hardware in a custom gearing solution. Don't believe me? Have a...