Flying to Mexico City

When we got to Dallas Airport, we had a stopover of few hours, so we decided to have some Texan steak – or at least as Texan as we tried to get without leaving the airport.  We ended up at TGI Fridays.  It was the first steak that I’ve had in a long time, and I definitely could use another one.  The steak even came with “Jack Daniel’s Sauce”, which made it that much better.

After eating, we met up with two others on the team who had flown from San Jose and Toronto.  After a four hour flight to Dallas, and other few hours of stopover there, we had to fly for another two and a half hours to get to Mexico City.

As my friend said, “it’s like China happened”.  The Benito Juárez International Airport was probably the most disorganized airport I’ve ever seen.  It’s as if every single flight landed at the same time.  The lineup to grow through customs took at least forty-five minutes.  During this whole time, everyone was tired and wanted get their sleep.  A lot of the people on the team hadn’t slept the night before (rather than sleep 2 or 3 hours to wake up early for the flight right?).  While in this lineup, we saw a couple of other RoboCup teams landing as well (Skuba, MRL, among others).  After finally getting through customs and a security check, we got a ride to our hostel via transportation that we organized with the hostel prior to our departure.

Hostel Mundo Joven Catedral

The hostel we stayed had very nice staff that really cared about making its guests feel safe there.  It’s a common feeling among travelers to think that Mexico City is definitely not one of the safer places to travel to.  To combat that, the hostel had its own security guards, security cameras, and they even called legitimate taxi’s for its guests.  They even told us which direction to walk when leaving the hostel to avoid going to the shadier parts of town.  Furthermore, it was situated in the historic center of Mexico City, within walking distance of the Metropolitan Cathedral of the Assumption of Mary of Mexico City and the Plaza de la Constitución.  From some of the rooms at the hostel, there was a nice view of the cathedral.

Work Day

We spent the next day working on the robots to make sure none of the mechanical parts had been affected during the flight from Vancouver.  We had packed all the robots in a regular suitcase with packing foam all around it to protect it.  Looking over the mechanical parts, everything was in order.  The main things we had to fix were tightening screws, adjusting the wiring etc.  The software team had very little to do because they’ve written all the code they could, and just needed robots to test with.  The electrical team on the other hand, toiled tirelessly to troubleshoot all the boards and make sure they were all functioning properly.

RoboCup Begins!

We arrived at the competition venue, the World Trade Center at 8 AM to find a slew of other teams patiently waiting to register.  After probably an hour long wait, we all finally moved in and set up our work places.  When we looked at the field the robots would be playing on, we noticed that the organizers hadn’t yet set up the cameras yet (required for the robots to “see” where they’re going).  This meant that no teams could test.  Teams that were ready could only wait until the organizers got those set up.  Because of this delay, the games had to be delayed as well.  This gave us more time to get the robots ready.  For the next little while, we were the first team to arrive and the last team to leave everyday.  The electrical team needed all the time they could get to finish everything.

Because we had already finished most our maintenance work the day before, there wasn’t a whole lot we could do.  The electrical team had to continue working on their stuff to get as many robots ready as possible.  For the next day and a half, we let the electrical team do their work and we’d help them along the way by replacing parts that were broken (encoders and such).  Otherwise, there wasn’t much we could help with.

Food for the next Week

When we got hungry during the competition, we did a little bit of exploration to find food.  Eventually, all the teams wound up at the same shopping mall for food.  There was a supermarket downstairs to buy water and a food court upstairs with a variety of foods.  We went to this mall pretty much everyday for as long as we were at the World Trade Center.  One day we’d try Mexican food, other days we’d try plain-old hamburgers and other days we’d try even Chinese food (at least the white person’s interpretation of it).  It wasn’t really healthy for us, but we figured it was only for a week.

For dinner, most teams ended up ordering pizza from the nearby Domino’s.  We ate it so much that everybody got sick of having pizza.  Sometimes, we’d have dinner with other teams at our hostel restaurant so we could get to know them a little bit better.  After all, the competition is more about mutual learning and robotics advancement rather than about winning.

Let the Games Begin

Because our team wasn’t that ready to begin with, we had to forfeit our first game against the Immortals from Iran.  By the time we got three robots up and running, we played against the RoboJackets from Georgia Tech.  They only fielded five robots out of the total six.  For most of the game, both teams played pretty evenly, despite their two-robot advantage.  All was going well until one of the opponent’s robots chipped the ball that hit the top of one of our robots, bounced off and rolled into the goal.  In that particular situation, the referee had called an “indirect free kick”, meaning the shot, even if it went in the net, would not count.  But unfortunately, that rule was not applicable because it hit off of another robot.  It was an unlucky goal for us, and we definitely could not score a goal to tie up the game.  We ended up losing one-nil.  For the next few days, we kept complaining about that goal.

In our third game, we played against RoboFEI from Brazil.  There were so many good scoring chances in this game from both our teams that made this game so intense.  Even though we were only watching machines play, everybody cheered them on.  We had four robots on the field this game and they all worked like a charm.  The mechanical system, electrical system, and the artificial intelligence worked so well together.  It was a great feeling for everyone on our team – to see our design work.  After almost a year of hard work, this was it.  We saw our robots move, intercept balls, shoot on the goal, etc.  A lot of the robot shortcomings from the North American Open were also dealt with, such as the problem of the break beam sensors not working, and the robot not moving accurately on the field.  When we scored, we cheered so loud that every single person in the room could hear us (there were probably about 1000 people in that room).  We all got an immense feeling of satisfaction in seeing our working robots score their first goal.  A few minutes later, the other team scored a goal.  It didn’t matter to us, we were still high in the clouds in terms of our mood.  The game ended 1-1.  Despite the tie game, everyone on the team was so happy in seeing our robots work, it didn’t matter what the result was.

This was a great morale boost for the team because for our forth and last game, we played against BRocks from Turkey.  This time, we had our full fleet of robots.  We played our first six on six game.  Yet again, we saw our robots work.  Nothing broke down during the game and everything just worked.  It was quite rare for us to just put our robots on the field and have nothing go wrong.  At one point, our robot shot the ball into the opposing robot and a piece fell off of it.  We knew our design worked when stuff like this happens.  This game was less intense for us than our previous game, but we did end up winning.  That put our record at 1 win, 1 tie, and 2 losses – a total of 4 points.  Unfortunately, this wasn’t enough for us to advance to the next round of the competition and as a result we finished 13th out of 20 teams in the league.  Not so bad for having zero working robots when we got to Mexico.

After the official games, we played a couple friendly games with other teams.  The first game we played was against the Mannheim Tigers.  The game was going well, until we found problems where some of the screws on the robot weren’t tightened sufficiently.  As a result, things well off the robot when we played.  It was quite embarrassing to see.  At least it was only  something minor like putting in a screw, and not something major like a design problem.  In our second friendly game, this time against ER-Force from Erlangen, we found some electrical parts frying randomly on the board, which wasn’t good either.  Out of six working robots, we now had three – still a net gain I guess.

After we were done playing, we watched the other teams play for first place.  From watching their games, it was clear that they played on a way higher level than we did.  Everything that their robots did were way better than ours.  Shooting was faster, chipping went further, robots moved faster, kicks were more accurate, etc.  Everything about their robots was just better.  There is definitely a lot we could learn from these teams.  The final winner of this year’s competition ended up being Skuba from Thailand, who beat ZJUNLict from China.  Both teams analyzed each others strategies for days, but only one team could come out on top.  And now for the fourth year in a row, Skuba remains the undefeated winner of the competition.

Other Leagues in RoboCup

During our idle time, we walked around the other rooms to see how the other teams were working.  RoboCup has many different competitions under its name, while our Small Size League competition is only one small part of it.  Leagues range from soccer robots, rescue, simulation, to even home care robotics.  In the home care robotics league, the competition involved a robotic navigating through a mock house to perform certain chores such as picking up objects to hand to people, speaking and hearing instructions, etc.  It was an admittedly difficult task to do for these robots, but many teams were quite successful at it.

Accidents Happen

Just like in the North American Open, there was yet again another accident involving batteries.  Except this time, nobody noticed and the whole battery lit up in flames.  Somebody just yelled “fire, fire!” and started trying to pat it down with something.  Knowing that I was too far away to do anything, I just took out my camera and snapped a picture of the whole thing.  Eventually, someone just poured lots of water over it to put our the fire.  In retrospect, that might not have been a good idea since water in an electrical fire is not really a good thing.  Nobody got hurt though, which is good.  Afterward, the organizers didn’t let us charge batteries nearby our work space anymore.

Some Design Shortcomings

Knowing that our ball kicker would be able to withstand impacts of the ball, what we had forgotten to analyze was how well the kicker would hold up if it hit a object fixed to the ground.  We found out the hard way at the competition after a few games when we discovered that our robot kicker head was bent out of shape.  We also had a lot of turf buildup inside the robot that was enough to slow down the wheel during the game.  This turf had to be cleaned out after every match.

For the kicking mechanism, the robot uses a solenoid/plunger mechanism.  Activating the coil would cause the plunger inside the core to move quickly to hit the ball.  A rubber band secured to the end of it would allow the plunger to return to its initial position.  The problem with this setup was that the rubber band would easily break and had to be replaced after every game.  When we took out the rubber band, we could always see cut marks along it.  In another instance, a chipper solenoid on a robot almost popped out.  It’s not really clear why this happened at all, but it could have been a screw that was not very tight to begin with.

RoboCup Closing

To close the competition, there was a soccer game where humans played against the middle size league robots.  It was pretty funny to see the robots struggle to take the ball away from people who could handle the ball way better.  At the same time, the humans were really scared of the robots since if a human ever got hit by the kicker head from the robot, it would break bones.  The robot goalie however, proved quite competent in blocking shots – better than the human goal from what I saw.  Or maybe the human goalie wasn’t trying very hard.  I’m not sure who won the game since I didn’t watch the whole thing, but it was still really interesting to see.

Afterward, all the teams packed up their things and waited for the closing banquet.  At the closing banquet, they served a standard meal for everyone.  It was a really good chance for teams to celebrate their achievements and finally relax a little bit after the competition.  Everyone deserved a rest after all of that.

First Real Tour of Mexico – Teotihuacan

After the competitions ended, most teams stayed an extra day or two to see the sights in Mexico City.  The organizers of the Small Size League were nice enough to organize a tour for everyone the day after the competition ended.  Most of the SSL teams went with us to the Aztec pyramids in Teotihuacan.  The tour first showed us how their predecessors used different plants and minerals to make tools such as knives and sewing thread.  That part was interesting at first, but I think what a lot of us really wanted to see were the pyramids.  Afterward, the tour guide led us to the gift shop.  For some reason, most of the people were so interested there, it took about an hour for everyone to finish so that we could move on with the tour.  After the gift shop, we finally made it to the pyramids.

After walking up and down the pyramids, we had lunch and went back to Mexico City to see the Basilica of Our Lady of Guadalupe.  This was one of the most visited Catholic shrines in the world.  But because I had already visited so many churchs and cathedrals from my tour around Europe, this part of the tour was less interesting for me.

Historic City Center

The team would fly back to Vancouver on the day after visiting the pyramids.  But before leaving, we made sure to visit the Metropolitan Cathedral of the Assumption of Mary of Mexico City and the Plaza de la Constitución.  In the plaza, hung a giant flag of Mexico.  This is where the city center used to be, at least during the 19th century.

Going Home

After 10 days in Mexico, we all longed to go home.  It had been a long week – full of stress, adrenaline pumping excitement and overall a good experience.  But after all that, we were ready to go.  We flew out in the afternoon from Mexico City.  Apparently, at around the same time that we were at the airport in Mexico City, three cops had been shot to death.  While we were there though, we didn’t hear anything of it.  We safely arrived in Dallas for a brief stopover and arrived back in Vancouver at about 8:30 PM, just in time to go home, wash up and go to bed.

More photos here

After about three years or more of laptop use, one of the components that is likely to break is something in the LCD assembly.  The LCD assembly is a collection of components that allows the laptop to display things on the screen.  The following is a list of the primary components and their purpose:

• LCD Panel – the part of the assembly that displays the images and is what people are looking at when using the laptop
• CCFL Tube/Lamp – provides the light on the display.  The LCD panel provides the image, and the lamp provides the light required to see the image.
• LCD Inverter – transfers power to the CCFL lamp

The following instructions are general and do not pertain to one specific model of laptops.  The theory still applies however.

Problem Symptoms

In problems regarding a laptop display, these are the common problems among others that are quite prevalent among laptop users.

• Black corner – on one corner of the screen, a black triangle can be seen. The mouse can be moved under it, which shows that the LCD is just not displaying that part of the screen. The black corner is also hot to the touch. In some cases, the black triangle can change size over time (on the order of a few minutes or hours).

• Dim screen – the LCD is still displaying a picture, but it cannot be seen because there is no backlight.  Shining a bright light (such as a desk lamp) illuminates the screen slightly, but not to the brightness that the screen was at before.

The first problem tends to lead to the second one.  The CCFL tube burns out and leaves a dim display.

Determining the Cause

In general, if one experiences at least one of the problems above, there is a clear hardware issue.  Some exceptions are when one has turned the brightness all the way down, but this usually isn’t the case for people.

If one simply sees a dim display, it is due to either the CCFL tube or the Inverter.  It is not possible to to determine which part is the culprit without opening up the laptop.  Refer to instructions specific to the laptop in question to open up the screen assembly.  During disassembly, take note of what screws go where.  Different sized screws get used for different places and it is very easy to forget which ones go where.

The first image shows the laptop with the cover taken off.  The second image shows the disassembled LCD assembly with the CCFL tube lying on top.

CCFL Tube

Finding the CCFL Tube on the laptop is a lot more involved than finding the Inverter.  It involves opening the LCD panel (see this website for instructions for a Dell Inspiron 1520).  Visual inspection of this part can sometimes show clear signs of damage.  Burn marks should be apparent.

If burn marks are not apparent, then the cause is likely due to the Inverter.  One can also test the CCFL Tube, by turning on the computer with everything still plugged in (but disassembled).  If the CCFL Tube lights up, then there is nothing wrong with the CCFL Tube.

LCD Inverter

It isn’t possible to test this part directly without the proper tools.  However, if one has a dim display but has checked whether the CCFL works, one can be more certain that the Inverter is the culprit by process of elimination.

The Inverter is the part in orange in the top photo.  The bottom picture shows the Inverter by itself.

Solution

Once the cause has been determined, the next step is to replace the part.  However, one has a choice:

• Replace the entire LCD assembly – costs more (~$100), but the labour is easier
• Replace the problematic parts individually – costs less (~$5 – $20), but more difficult labour

One source for parts is Ebay, but it might take around three weeks for the part to arrive.  This is cheaper than the $300 that Dell charges for shipping the laptop, buying the components and the labour.  Replacing these parts is an involved process will take at least one hour.

Here are some things to watch out for when replacing the CCFL Tube:

• It is difficult to take the part out of the LCD panel
• Watch out for dust that could get in between the layers in the LCD (will show up as black specs under the screen
• It is hard to lay out the layers flat again when the CCFL Tube is replaced so there might be some uneven lighting after the CCFL Tube is replaced

After replacing the parts, turn on the computer again and the screen should be bright again.

• Intel Core i3-370M Processor (2.4 GHz)
• Nvidia G310M Graphics Engine with 1 GB DDR3 Dedicated VRAM and Optimus Technology
• 4 GB of DDR3 1066MHz DRAM (2 GB x 2 slots)
• Intel Wireless 802.11 b/g/n + WiDi
• 500 GB Hard Drive (5400 RPM)
• Windows 7 Home Premium (64 bit) Operating System (which I upgraded to Pro)
• 13.3-Inch HD (1366×768) LED Display
• HDMI Port
• USB 3.0 port
• Bluetooth
• 8 cell 5600 mAh battery

The one thing it doesn’t have that I realized just now is that the computer doesn’t have an optical drive. I didn’t know that before. I guess I assumed that all computers except for netbooks have them. It’s not really a big deal though.Since my laptop kind of died on me earlier, there weren’t many things I could do to solve the problem. I pretty much only had three options: get my laptop repaired, buy/borrow a monitor for the duration of my stay, or buy a new laptop.

Repairing my laptop was definitely the first thing I tried. I researched on how to fix it, but I couldn’t even get the screws out to even peek at the insides. Right now, I still think that the problem inside the computer is just a loose connection. Unfortunately, I can’t confirm that. I could let Dell fix the computer, but my warranty expired a long time ago. I also bought the computer from Canada and would have to go through lots of red tape just to get it repaired by Dell Europe.

The next thing I tried was to find someone who had an extra monitor I could borrow. Since all my friends in Germany are all interns or thesis students, they all had only a laptop and not an extra display. Although, I did manage to borrow one for like a week until I had to return it. I could have bought a new monitor, but then it would have been really been difficult to bring home a 20 something inch screen (if I’m buying a monitor to keep then I wouldn’t buy anything smaller). I didn’t feel like buying a cheap one and just leaving it behind when I leave Germany either.

In the end, I ended up buying a new laptop (with much financial assistance from my parents). I figure my old laptop is getting old anyways (2007), and for the past year and a half it had been failing to keep up with my intense computer usage habits. When I return to Vancouver, I’ll get this laptop repaired and then my parents could use it (or my brother if he decides that he needs to bring a laptop somewhere).

After almost four years of using my Inspiron 1520, its age finally caught up with it and its light literally went out.  The backlight refuses to turn on now.  I came back from Berlin last Monday and found my computer in this state.  I left it off during that time too.  During this time, I had trouble doing any blogging and uploading any photos.

Google told me that the problem lay with either a loose connection, the inverter or the lamp.  I tried to check this out myself and open the computer case, but the screws refused to budge.  People online somehow got theirs open, but I couldn’t.

Unfortunately, my warranty expired so I’d have to pay to get this computer fixed.  I looked at my options on the Dell site and the North American Dell Support refused to help me and kept referring me to the European side even though I bought my computer in Canada (I really don’t know what these guys at the call centers are doing).  After about three calls to the support line, I finally found someone helpful and she told me that I had to change my laptop registration such that it showed a European location before I could get it fixed.  An alternative option would have been to send the computer back to Canada to get it fixed.

What I did instead was just buy a new laptop.  My laptop is already super old and already can’t really keep up with my tasks anyway, so I suppose it’s time for an upgrade.  What surprised me was that laptops in Germany (from their Best Buy/Future Shop equivalents anyway) cost so much more than in North America.  In fact, it was cheaper for me to buy my computer in Canada and get my parents to ship it to me rather than buying it locally.  I’m sure there are cheaper places, but I don’t exactly know how to look through all these German websites.  Another added advantage in buying from Canada is that I’d have a computer with the US Keyboard layout rather than the German one.  And in the future when my laptop needs repairs, it’ll be easy.

In the meantime, I’m using a 17 inch LCD screen that I borrowed from a friend.  This will suffice until my new computer arrives.  No more shining a lamp at my computer screen and squinting my eyes to see the screen anymore.  I also don’t need to be using my phone to go on the internet at home either.

• Nominal Size
• Thread Form Type
• Major Diameter
• Pitch
• Root Radius
• Pitch Diameter
• Minor Diameter (Male Thread)
• Minor Diameter (Female Thread)
• Thread Height (Male Thread)
• Thread Height (Female Thread)
• Tap Drill Diameter

Link: http://www.newmantools.com/tech/threadm.htm

Update 24 Sept 2011: Added info about screw head dimensions
http://www.csgnetwork.com/screwsochdcaptable.html