Friday Night Robotics – Gyro in MANOI’s Back

Posted by Erin, the RobotGrrl on Friday, June 11th, 2010

Friday, June 11th, I originally wanted to work on BubbleBoy and the swashplate, but it seems as though the axels that I bought ages ago were too big. They could only fit in the big servos, but BubbleBoy uses micro servos.

MANOI’s gyro and accelerometer were in need of being more securely mounted, and the area in MANOI’s back is a great place to mount them. You can hardly see them, but the gyro is mounted on the right wall, and the accelerometer is mounted on the back wall. There’s a piece of foam in there to protect them, and keep them more secure.

The Serial Servo Controller (SSC-32) is what is mounted on top of these, and it was previously only attached to MANOI by velcro. Now there’s some wire tied through its waist and through the SSC-32 to hold it in place!

That was about it for that Friday. The readings from the accelerometer and gyro are definitely less jumpy, and MANOI’s center of gravity is moving around less now.

Posted in: MANOI, Projects, Robot.

Grabbing MANOI’s Accelerometer and Gyro Data

Posted by Erin, the RobotGrrl on Wednesday, June 9th, 2010

Last FNR I embedded MANOI’s Accelerometer and Gyro into its back. Usually what people do first when they add these motion sensors is make their robot self balancing. For now, I’m going to see if I can do something a little cooler.

The idea stems from a Fast-Fourier Transform result for sound- where you can see the various volumes and such. (Check out my Processing Fancy FFT). What I’m aiming to create is a FFT for motion. Basically, if you move MANOI around, the algorithm will be able to detect a pattern and do stuff afterwards. Essentially what this is leading up to is an interesting dancing robot. =)

I’m starting off with a Processing program that will visualize and log the data (see above screenshot). I envision a split-view display with two cubes. One will be showing the live sensor input, the other will be showing the results of the pattern algorithm to the live data.

No idea yet how the algorithm will turn out. I’m probably going to start at a very basic level, and perhaps add complexities on later. It will be interesting to see how this will turn out!

Soon to be blogged…

• The FNR that I mentioned, but didn’t blog about
• RampageRobot!!!
• RoboGlyphs

Posted in: Programming, Projects.

Friday Night Robotics – RGB LEDs

Posted by Erin, the RobotGrrl on Saturday, August 8th, 2009

A few weeks ago, I added four RGB LEDs inside of ping-pong balls to MANOI’s head. The goal of this is to let MANOI express some colour. From colour, we gain meaning. The meaning we usually tie to colour is emotions! (and food, haha)

I also plan to give MANOI ears, so when they move in a certain way, we can tie emotions to their meaning.

In any case, controlling RGB LEDs is fun. In one LED you have four leads for red, green, blue and ground. This means a whopping 16 leads in my scenario! :O

What I did to organize this was I used 5 24″ servo extension cable, and 1 12″ cable. The 12″ and one of the 24″ are for ground, and the 4 others are for the RGB leads. Eventually I’ll combine all of the grounds together.

Since the Sanguino only has 6 PWM ports, two of the RGB LEDs have to be combined together. Later on, when I get shift out PWM chips, this will be a different story

So I coded in lots of funky functions, there is just one last function that I have to make… I want to be able to fade LEDs at the same time from different starting points to different ending points. I’m sure if I take the brightness value (which is 255), and map it to 100, I can come up with a math function that will let me do that. It will probably have something to do with jumping numbers and mod. I’m going to be thinking about that tomorrow It is a pretty easy problem to solve

Mounting the gyro was fun. I actually started this around the beginning of the week, but I got delayed a few days because I ran out of velcro… so I bought more velcro, and I added it to a stable DOF attached to the torso of MANOI.

The point of the gyro is that it measures movement. It doesn’t measure where you are relative to where it was. I actually got stumbled up with that at the beginning.

Though, in order to use the gyro effectively, MANOI has to be able to WALK! I spent sooooo much time this week trying to make MANOI walk, again. I’m no closer to the goal than I was ages ago. I think it will involve lots of patience and trial & error…

I’m still trying to think of the best way to make MANOI walk. Until I figure it out, I’ll be working on the extras I want to add in some sensors for the RGB LEDs, specifically an IR and an accelerometer. If MANOI is moving with nothing in front, the LEDs will behave differently than if MANOI is not moving with/without someone in front. ^_^

Posted in: MANOI, Programming, Projects, Robot.

Cool Gear from Honours Program

Posted by Erin, the RobotGrrl on Monday, July 13th, 2009

In Clarkson’s Honours Program, for summer research you get $300 for anything related to your research.

In the hobby robotics world, $300 can do a lot of damage!

I just wanted to mention here some of the super cool gear I have gotten from the Honours Program this summer, and how I plan to use it:

Purchase #1 (Sparkfun.com)

• Arduino MEGA ($64.95)
• 2 XBee 1mW Chip Antenna ($45.90)
• 2 XBee Explorer Regulated Boards ($19.90)

Total: $134.65
Remaining: $165.35

So the Purchase #1 was from Sparkfun, and it came in a nice-sized box. I love the Sparkfun boxes because of their colour and ruggedness. It’s like a super cardboard box!

The Arduino MEGA was just something that was needed. Originally, I intended for it to be used with the computer, attached to Processing, but it is being used for the control of MANOI’s servos. I remember I blogged about why I changed, it was a combination of the space, the fact that it fit in the box, and the way the headers are. It is even more better with the new soap boxes!

Two XBees and adapter boards, well that one is hard to figure out (lol). They are going to be used to transmit data from the computer (Processing) to the Arduino MEGA. I really like these boards because of their red colour and surface-mount LEDs, but the fact that it doesn’t work witht he FTDI cable sort of makes me want to use adafruit’s boards. However, I can use adafruit’s boards to program the XBee and use the sparkfun boards for the actual stuff.

Purchase #2A (Pololu.com)

• 0.100″ Breakaway Male Header ($0.99)
• 0.100″ Breakaway Double-sided Male Header ($1.49)
• Power HD Sub-Micro Servo ($9.95)

Total: $17.38
Remaining: $147.97

The normal male headers are needed for just about anything, especially when you are making the proto-boards (which I plan to do for the RGB LEDs). However, the double-sided headers are quite different. These I can use in jumpers to instantly make them male jumpers. It’s much cheaper to do this rather than just buying male headers!

I was supposed to get two servos, but there was a communication malfunction so I only got one. The servos are going to be for ears on MANOI. Ears are a simple, yet effective, way to make a robot show emotions & actions. I don’t really know where this stems from originally, but it feels like Mickey Mouse cartoons really make this evident as he has big ears, bigger than his own head!

Purchase #2B (Sparkfun.com)

• 2 Breakaway female headers ($3.00)
• Gyro Breakout Board – MLX90609 – 300 degree/sec ($59.95)

Total: $69.17
Remaining: $78.00

This has not arrived yet… but I am so PSYCHED to get my hands on a GYRO! Gyro sensors measure rotation. So, I could put this on MANOI and attach/make an interrupt loop so that if it senses that it is falling, it will try to not fall OR maybe I could get it so that a capacitor holds reset low for 5 seconds so the MEGA & SSC-32 would not be on when MANOI falls and bounces. THIS IS SO AWESOME!! I’M GETTING A GYRO!! WOOT! I know you are all jealous!

The two breakaway female headers are also useful to have when proto-ing boards.

So I still have $78.00 left to spend. I still have to buy that second servo, and while I’m at Pololu.com I’ll probably also buy some servo extension cables.

If I have enough money left, I’ll probably buy a second gyro so that I could mount both of them on MANOI’s knees to tell if one leg is falling faster than another.

This is so exciting!!

UPDATE: Purchase #3 was just made

Purchase #3 (Pololu.com)

• Power HD Sub-Micro Servo ($9.95)
• 5 x #780 Servo Extension Cable 12″ Female-Female ($14.95)
• 5 x #785 Servo Extension Cable 24″ Female-Female ($18.75)

Total: $59.60
Remaining: $18.40

Purchase #3 will get me my 2nd servo that I need for the ears, and will give me some servo extension cables that I need for the lights. I wish the servo extension cables cost less, but what can you do.

Posted in: Projects, Robot, School.