Friday Night Robotics – Wild Thing

Posted by Erin, the RobotGrrl on Sunday, June 28th, 2009

This actually wasn’t on a Friday (Friday I was making an iPhone app), but rather Saturday.

Since the Sanguino requires too many female headers (which cost money, and I don’t have any), I decided to switch up to the Arduino MEGA. It fits in the box that is already there, so it is all good.

Originally I thought that the Wave Shield would work on the MEGA, but it turned out that it didn’t. What I ended up doing instead, though was using one of the MEGA’s extra Serial lines to send a command to another Arduino to start playing music (on the Wave Shield).

I used my iHome speaker thing that I bought at Walmart for $20. Pretty good value, and it’s purple.

It was pretty fun. However, I only used the motions that I created a while ago when MANOI’s knees were broken. A blog post is coming shortly about the previous FNR where I fixed the gears

I even attached a wild duck to MANOI’s head for the occasion:

Here is a video, it is not too good:

Friday Night Robotics – Wild Thing from RobotGrrl on Vimeo.

See, the problem in the video (when I had to shake it) was that the TX line to the SSC was loose. It does this from time to time. Especially after switching boards!

Posted in: MANOI, Programming, Projects, Robot.

Hockey MANOI – a summary

Posted by Erin, the RobotGrrl on Saturday, January 3rd, 2009

I made a pretty good summary of Hockey MANOI in this thread at Trossen Robotics forum. I figured I should post it on my blog because it is a good summary and I broke it down into easy to read parts, so it’s like a whole JOURNEY of awesome!

Hello TRC World!

My project is a hockey playing humanoid.

It uses a MANOI AT01 kit, controlled by an Arduino (with an ATmega328) with a Wave Shield, and a SSC-32.

Humanoids have always been associated with walking or running. This project focuses on a different action for humanoids, skating. The end result of this project yields an interesting vision of the possibilities of skating robots.

Introduction

The idea came around when I was trying to make my humanoid (MANOI AT01) walk. Instead of taking a “big bite”, I decided to take a smaller bite and make it slide its feet. However, I quickly realized that when it slides its feet, it looks exactly like a newbie Canadian hockey player!

A Canadian newbie hockey player begins to skate by almost walking. Although the skater doesn’t go far, he does move forward due to the friction between the blade of the skate and the ice.

When I did notice this, I quickly grabbed some lego to create MANOI’s own version of skates, which are similar to rollerskates. I mounted the lego onto the feet using velcro.

The hockey stick I just found laying around. I had to cut a bit of it off, as it was too tall. I use tape and tie wraps to keep it mounted to MANOI.

Development

Development on this project was mainly trial and error. To get all of the motions correct so they all balance together was critical.

Instead of using the controller board that is usually used to control the MANOI, I did a major transplant and substituted it for the Arduino and SSC-32. This allows me to have much more flexibility in terms of sensing and creating motions. The H2H software was too problematic.

Usually what would happen is I would draw out a motion, on paper, that I would want to create, and I would put it into MANOI. Sometimes I got it first try, other times I didn’t. However, the cool part is that a lot of the motions stemmed from the ideas of other motions.

For instance, in the video of MANOI Skating with music (seen below), the motion where MANOI is running is actually a faster version of the sway motion! That was really surprising.

The development for the Wii nunchuck part of the code was quite easy as I had already established all of the variables and settings of when the nunchuck is tilted left or right, forwards or backwards. Instead of using real numbers for it though, I just defined a “home position” of the nunchuck, and subtracted or added numbers to the accelerometer axis, x y and z.

The music part of the wave shield was quite fun and straight forward. I looked around for the songs, and put them on a SD card which plugs into the wave shield. From there, it was just a simple method call inside of the Arduino.

Once the above developments were done, I wanted to create a version of MANOI that could sense if a ball/puck/object was there. I did this by using LDRs and LEDs.

Rest assured, I would have used IR Sensors if I had any This was the best alternative I had, though!

On the left side of the sticks the LEDs are in a yellow casing, and on the right side they are in a clear casing. There is some effect on the reading, however their values change precisely the same when an object is in front of the stick.

The black construction paper enclosure around the LDRs was required to direct the reading. Otherwise, the light from the LEDs saturated the reading and no difference was seen when an object was present or not.

I observed the change between the readings of when there was an object present, and when there was not an object present.

From this, I created a simple neuron, where if the input values succeed a predefined threshold, it will perform an action. In this case, the action would be to shoot the object.

I had to tweak the threshold a little to make it work with smaller objects, such as a roll of electrical tape.

In the video below, you will observe that it does work with a roll of electrical tape, a ball, and a spool of lead solder (the LEAD solder isn’t mine, it’s my DAD’s because he can’t use non-lead solder like the rest of us -_-;). The spool is white, which proves that the theory does work, meaning that the light that is reflected from the LEDs back into the same LDR board does not obscure the readings.

Results

Here are the videos that you can look at!

This is the first video, where I was just getting the motions down.

The program is basically a sequence of movements:

- Forward 6 times
- Shoot 3 times
- Backward 6 times
- Shoot 3 times

As you can see, the forward and backward movements both result in MANOI moving backwards. As I later found out, through trial and error, it was due to the Arduino and power cords limiting the movement of MANOI! Once they were mounted properly, it worked much better.

This is the second video, where MANOI is controlled by the Wii nunchuck!

You press Z to shoot, and you hold C and tilt to move it. MANOI can move forwards, backwards, left, right, and home.

This is there third video, where MANOI is playing a little game of hockey by himself while listening to some music. The song that you first hear is the Hockey Night in Canada theme song!

This is the last video, where MANOI can autonomously decide if he should shoot or not.

(The quality in that video is quite yucky, please check out the video on [URL="http://vimeo.com/2641041?pg=embed&sec=2641041"]vimeo[/URL] if you’d like to see it in better quality)

Conclusion

In conclusion, this project was SO much fun! The only time I didn’t enjoy it was when I was trying to hold MANOI, who was whacking me with its stick, with one hand and trying to type in some code with my other hand.

My favourite part was watching people play with the Wii version of the code. They really enjoyed it!

I also liked making the AI part too, that was pretty fun.

Next Steps

The next steps would include coding a modified version of the Bayes filter algorithm to predict if an object is in front of the stick or not.

More sensors would be fun, like three proximity sensors mounted on the front, left and right. This way MANOI could avoid opponents trying to take the ball off of it.

I would also add two more servos in the leg that would allow rotation. This would then allow me to create a more realistic skating humanoid, where there would actually be a stride.

Perhaps I could also add a camera to the head so that it could track where the ball/puck/object is.

That’s my project, I hope you like it! ^_^
You can see more of everything I mentioned at robotgrrl.com

Posted in: MANOI, Programming, Projects, Robot.

All Coding Ahead

Posted by Erin, the RobotGrrl on Saturday, September 27th, 2008

Woohoo! I fixed my soldering iron – it’s FANTABULOUS now! All I did was file it with an Xacto, and sanded it a bit. Now I can finally tin the tip (before I couldn’t) ^_^ It’s amazing!

My two WiiChuck adapters are finished – I tried to make it work this afternoon, but for some reason the WiiChuck header file by Tom Igoe isn’t working!!! :S I’m confused… maybe it’s because I’m using Arduino 0012. I’ll be playing around with it more tonight.

The WaveShield is all soldered up I’m thinking about which song I should put on my SD card to test it out… hmmm

There’s so many fun things to do eeeeee all of them are now at the coding stage yay!

Posted in: Programming, Projects, Robot.

Stuff!!

Posted by Erin, the RobotGrrl on Wednesday, August 20th, 2008

^_^ Thanks to very kind people, I had a $200 gift certificate at Adafruit and was able to buy stuff!

• Arduino
• 2 ProtoShields
• Arduino bootloader
• Multimeter
• Boarduino
• Motor Shield
• Wave Shield

All of these are going to be extremely helpful @_@ In fact, the old multimeter broke just the other day ^^;

What’s a little cool is that the Arduino now has Italy on the back! Someone who had the Arduino at Stanford also had this style, so I guess it’s kind of cool that I had one of the Arduino Dicemilas without the map The motor shield sounds a lot of fun… as does the wave shield! I’m not sure which ones I’ll put together and test first…

Either way, I now have lots of interesting stuff to keep me entertained for a while longer

Thanks Ron & Evelyn!!!
(and I hope I won’t blow any of them up)

Posted in: Other, Projects, Robot.