New domain name!

I finally have my own domain name,! My blog at will no longer be updated.

At first I tried to register, but they didn’t let me because I don’t live in Germany (.de). Oh well.

After some research, I decided to go with Namecheap as my registrar. They’ve reasonable prices and the UI isn’t horrible. I just tried their online live support—immediate response, and problem solved in 15 minutes! I’m happy so far.

I spent hours last night trying to get the domain name to point to my home server (i.e., my laptop). Only after the live support session did I find out that I had to enter my IP for both the www and @ fields in the host records. Additionally, changing host records is not an immediate process. The domain name will actually go down for a few minutes with each change.

Until I get a dedicated server set up at home (sometime this summer), I will host my website on the same server used by the robotics team.


Tricopter: Electronics

(Disclaimer: the photos are blurry because my cell phone camera can’t focus on anything closer than 3 feet.)

The underside of my Seeeduino Mega protoshield

This is the underside of my Seeeduino Mega protoshield that will hold most of my tricopter’s electronics together.

I wired up my accelerometer (BMA180) and gyro (ITG-3200) a few days ago without too much trouble using their respective datasheets. I also put together a basic integrator for the gyro outputs to calculate angles, although I discovered that since the gyro drifts at a variable rate depending on the chip’s temperature, I can’t use a constant calibration value. I’ll have to look at that later. For now, you can see my code on github.

SMD LEDs soldered to protoboard. Blurry, but they're there!

My little victory today was having successfully soldered surface-mount LEDs (1206) to the protoboard, resistors and all (they’re the four yellow smudges!). The lights will indicate power, RSSI, and data I/O. That was the easy half-hour.

I spent three hours figuring out the schematics of my XBee Explorer board from SparkFun so I could plug the XBee directly into my protoboard. I don’t want to wire the explorer board to the protoboard because 1) that would mean two boards to mount to the tricopter chassis and 2) I get higher current capacity on the protoboard that I will need when I eventually upgrade the 1mW XBees to the 100mW version.

Fail schematics

This is my rough draft of the circuitry before I started soldering. It’s evident I got confused. I also realize now that those schematics are full of errors, but it’s not like you can read the scribbles, anyway. BAH. I’ll post more helpful CADded schematics when I have everything finalized.

The XBee datasheet was of substantial help. The schematics and CAD files on SparkFun’s product page for the explorer board also helped.

At this point, I should make it clear that wireless communication through the protoboard is not yet working. Pretty good progress for three hours, though.

Fortunately, I didn’t fry any components, not even any of the rather delicate LEDs. I scavenged a diode off a scrap motherboard, though I realize I must have wired it in backwards, perhaps causing my data transmission (the lack thereof) woes. The RSSI lights turn on if I try to transmit data (using a USB Explorer board), so I think the XBees are fine. I must have messed something up between the XBee and Seeeduino, like the diode. It’s also possible that the LEDs are drawing too much current, though I don’t see how that could even be true since the data LEDs aren’t lighting up much anyway.

I probably shouldn’t have skipped the breadboarding stage.

Senior Skip Day?


Sigh.. I procrastinate so much that I even put off blog posts that would take me no more than half an hour if I’d actually tried. Now that I’ve burned a few hundred kilocalories trying to get my head around flight orientation, here’s another summary of an event days past.

May 20th, the second-to-last Friday, was CV’s senior skip day. But instead of going to the beach, I:

  • Attended NCIIA’s Invention to Venture workshop on technology entrepreneurship
  • Attended the OSU Engineering Expo
  • Set up field for Roboshock

Invention to Venture

Given my limited business experience, much of the entrepreneurship discussion was rather theoretical for me, although I nevertheless picked up some concrete ideas I hope I can put in practice in the very near future. As the talks were several hours long in total and covered many different topics, I will summarize what I learned in a separate post (link forthcoming).

I do remember coming away from the talk with the definite impression that entrepreneurship is going to be one hell of a sleep-depriving activity.

OSU Engineering Expo

I don’t know about the others, but the computer science and electrical engineering presentations I listened to did not impress me.

The best of them, in my opinion, were the two seniors who had developed an automated AI class scheduling system for college courses. The system could use a database of courses from any university to organize a schedule for the four years of college around any specific course(s) the user flagged as a must-take, automatically taking care of all pre- and co-requisites. The vivacious senior to whom I talked presented me with a straightforward, working implementation and clearly stated goals. Not a novel idea, but well executed. It’s too bad that the system will not yet be available for use at OSU next year.

The others… had no sales plan (why should I care about your project?), had no obvious applications (you essentially made an RC toy; what are you going to do with it?), had no goals, no direction, lacked expertise (you developed this program; how do you not know what language it’s written in?), and/or was unoriginal (your project does exactly what Amazon does already). Or they just did a bad job of communicating their ideas to me.

I am not saying that OSU Engineering itself is bad. I just know that when I do my Senior Thesis Project, I’m going to do a lot better than that.

Roboshock field setup

The OSU Robotics Club hosts a full-scale FIRST Robotics scrimmage dubbed RoboShock every year. Our team is more or less in charge of the field, so some of our members helped set up the field at Gill Coliseum in the evening.

The actual competition was on the next day (a Saturday) from 10 am to 6 pm. Unfortunately, although our team was scheduled for 9 matches, we ended up doing only four or five due to WiFi interference issues (nearly every team started lagging).

At official competitions, there is a single router to which all teams connect their robots. OSU didn’t bother with that and had each team use their own router. Since the ClassMates are only capable of the 2.4 GHz band and there really are only three channels available for use (1, 6, and 11) for six FRC teams and who knows how many FTC teams (who had their own game going next to the FRC field), interference was inevitable. Hopefully that will change next year.

Things to do

In short, I’m not dead.

My job as co-captain of the team ended up being much more demanding than I presumed. I spent in excess of 600 hours during build season and several days away at two regionals.

Add to that the stress caused by college letters, changes in majors, AP testing, and a relentlessly growing list of unfinished tasks; I didn’t have the ease of mind to write anything.

My tasks in progress/on hold:

  • Kiwi drive robot
  • Tricopter
  • Mozart solo (concert in 10 days!)
  • Senior thesis project
  • Fix robot for OSU Engineering Expo and Roboshock next weekend
  • Two or three big emails I want to write to the robotics team
  • Robotics summer projects brainstorming/organization
  • Domain name registration/server setup
  • Job search

I took two AP tests last week and will take three more in the next two days. Tennis districts tournament runs from this Wednesday through Friday and orchestra state contest is this Friday. AP French make-up test this Thursday. AP Government make-up test this Friday. Concert next Tuesday.

Maybe I am dead.

Corvallis Camerata Wins 1st Place!

Although this is old news already (it happened last Saturday), our orchestra won 1st place in our division at the Northwest Orchestra Festival at Mt. Hood Community College in Gresham, OR! This is especially encouraging because we won despite having 9 of our 35 members missing due to the science fair.

We all played stupendously and totally blew away the competition with our quatro-quartet playlist:

  • Vivaldi: Largo and Allegro from Concerto in C Minor for Strings and Cembalo, F.XI., No. 8
  • Elgar: Allegro Piacevole from Serenade for String Orchestra, Op. 20
  • Shostakovich: Allegro Molto from String Quartet No. 8 in C Minor, Op. 110
  • Beethoven: Allegro from Quartet No. 4, Op. 18

I’ve already written several times (not necessarily on this blog) about how the Shostakovich Quartet No. 8 is the most awesome, raw, and honest piece of music I have ever played. This was the last piece we played in the final matchup with another orchestra for the first place prize. I went all out, as I hope all of our musicians did. The entire piece is blastissimo. This is music written with the blood and tears of all who have suffered.

The district competition is on the 15th. It should be a breeze.

Raiderbot X, 23 Days to Robot Ship: Lego Minibot!

Minibot proof of concept out of old Lego parts. The purple arms push against the pole, which angles the wheels into the pole to create a horizontal vector just strong enough to keep the bot on the pole. Took about two hours to make.

The bot is climbing up a 40 inch metal pole that is embedded in the concrete floor of our garage (for reasons beyond my imagination). Climb speed is about 6 in/s. Power is provided by a 13-year-old 9V Lego motor that is the wimpiest of the wimpiest Lego motors out there. It is being run on 12V.

The TETRIX motor we will be using in our actual minibot has 21.7 kg-cm of torque. This motor exerts no more than 200 g-cm of torque.

This is the first time in six or seven years I’ve put anything together with Legos. I think I’ve lost one of my tubs—I made this robot out of what few parts I could find. I need more gears!

Credits to my mother for taking the videos!

Raiderbot X, 26 Days to Robot Ship

This is an email I sent to the Raiderbot mailing list. I think it sums up everything that is going on.

Hello Raiderbot,

The bad news:

We are still a week behind largely due to delayed shipping of supplies and bad planning on my part. We have no driving robot, nor do we have a fully functional arm. If we add up all the hours, we have little over 60 hours (2.5 days) of work time left in the season. Also significant is the fact that too few people have been showing up.

The good news:

We have the aluminum tubing required for the chassis and have enough already cut for one chassis, ready to be welded using the jig constructed last week. HyTek has donated more plastic to us than we’ll ever need this year. We received the materials for the arm today and should be ready to start building tomorrow.

The roller claw beta prototype (demonstrated last week) looks very promising. Great job to everyone who helped design and fabricate it!

We have located a machine shop (Viper) that has the capabilities and is willing to manufacture our swerve modules (for the drive base). Spencer Hedrick is currently waiting to hear back from them regarding the cost and time of fabrication. We will know by Friday what the decision is. If the price is affordable, we hope to have the modules (and one robot) finished by the end of next week.

The scary stuff:

We need our first robot finished by the end of next week and our second robot by Wednesday of the following week. Please realize that although next week is only Week 4, it is already Week 4. It was our original plan to have the swerve modules finished first, but because the machine shops will not finish fabricating the swerve modules by the end of next week, we need to have everything else finished and nearly perfected by that time. This includes the:

  • Roller claw,
  • Four-bar linkage lifting mechanism (with milled aluminum tower),
  • Electronics board, and
  • The attachment of every necessary motor, sprocket, wire, belt, chain, pneumatic, and pulley we need on each of the two robots.

If all 46 members of our team meet and work consistently, this is entirely possible to accomplish in less than a week. At the current rate of attendance, however, this will not happen. Please also consider the fact that I haven’t even begun to describe what we need to do regarding the business plan, T-shirt design, battery cart, robot cart, scouting, pit build, pit panels design, minibot design, etc. There are too many jobs and too few people who come to meetings!

I am fairly happy about the attendance of the longer (Monday/Friday/Saturday) meetings; we got a lot done last weekend. However, attendance of the shorter meetings has been disappointing at best and unproductive at worst. Because we end two hours earlier, we need more people and dedication to maximize the use of our time in the shop.

It is our (me and Lipi) job as program managers to keep track of what resources we have to work with and keep the team on track for a successful season. Here, a “successful season” means we have completed the following (among other things) by Monday, 2/21, which is 26 days away:

  • 2 Robots
  • 2 Minibots
  • New website
  • Pit
  • Battery cart
  • Robot cart

The request:

We hope we are doing a decent job, but in being effective leaders, we depend on each of you. Regardless of your individual jobs, regardless of how small it is, regardless of how much it may or may not seem related to robots at all, everything you put into the team brings us closer to success.

We would like to go to every meeting knowing everyone will be there, but this has not been happening. We completely understand if you have other commitments (we do, too), but please let us know (by email, word of mouth, phone call) if you will not be there—then at least we can plan things accordingly so we aren’t caught short at the end.

Currently, the programming subteam is the only subteam that is (far) ahead of schedule. (Mechies, are you seriously going to let the proggies outdo you?) Congratulations. :)

Again, the roller claw is looking great. Please be there tomorrow to help finish building the arm and test it on the kitbot.


Lipi Gupta/Soo-Hyun Yoo