Blogs

Hi LMR-people!

 We at Eggshell-robotics.com just passed our first birthday and we managed to make a "mini-competition". We want you to draw/animate/builb or whatever creative about something YOU love about robots. The winner will receive a free EggshellRobotics-T-Shirt. For all the rules, look here.

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I am busy with the tweaking and fine tuning of my plywood version of prototype #5. I had no idea this would turn into a different design I now call #6.

This photo shows #6 in its leftmost position. It just cannot reach the extreme. There are still several small bits of plywood touching that should not be touching. Again with the jig and with the saw!

 

I am sad to say that I do not get much time to build any robots these days.. However, every now & then I get a few moments in my workshop.

Thanks to OddBot I got myself some phototransistors a while back, and now I had some time to play. I was thinking of making 2 robots send little signals to each other via a light beam.

Unfortunatly it's winter time in Denmark, and so I had to work under indoor light bulbs. And as you may know; Working with pulsating light under a such can be a pain!

Continuing where I left off (after a stiff binary interruption)...

This picture compares prototype #2 with an angled profile version:

 

The angled "L-profile" introduces a new property in the design: chirality. All of a sudden, it matters which direction you want to fold the joints. Compare the symmetric #2 on the right:

I started tinkering with "Theo Jansen legs" again (follow the link first if you don't know what that means).

I am prototyping in corrugated cardboard and trying to come up with a design that could be produced in large numbers (six at least) in plywood.

I bought myself a new pc recently and as for most new pcs it was lacking either a parallel port or a serial port.  As i was using the parallel port to program my robot i had to find a usb programmer that i could use.  I use atmel chips and i found a circuit design for the USBasp programmer, which consists of another atmel chip that converts the usb data into data that can be used to program my robot.  I thought that this would be a good opportunity to try and build my own pcb.  I got some info from http://www.fullnet.com/~tomg/gooteepc

This is my very first line following robot that is built around ATMEGA8. Construction and circuit are quite simple. Such a name- GOOFY is given because robot movements are somewhat clumsy. But hey! Its still working and doing his job very well! :)

There is two geared DC motors that are controlled using PWM. Tyres are the ones that are used in RC cars. Besides-these have a nifty looking. 

Ok Listen to the pirate song forward first

 

Then Listen to the last one (backwards) with lyrics

 

LOL OR WHAT?

Heres a video of the little scamp in action.

Have any of you seen this little thing? I was looking at it at the store and it looks awesome. The arms and legs are flexible; you can move them around and there don't seem to be any gears. I wonder if there is some sort of "tendon" thing going on. I want to try to hack one, but at $60, that's a bit much.

Hi.

Thought i would introduce myself since im new here and to robots in general.

 

Im john im a 28 year old programmer, LAMP mainly but a little java here and there. im working on one main project at the moment, guilbot. He's been a great learning curve for me and im hoping i can expand on him, this site is going to come in very handy.  

 

Anyway im friendly so say hi :D 

Sensing the living LMR community since 2008w43.

So, you accidentally stick a regular clear bulb in your Christmas lights (fairy lights [US] ?) instead of a fuse bulb. Next time there's a bit of a surge, there's no discernable weak point in your circuit and it takes out more than one bulb. Where do you start debugging that?

Sure, you could sit with a multimeter and probe all the bulbs to find the duff ones. Have you ever tried to attach multimeter probes to a fairy light bulb?!?! It's a nightmare. Specially when you only have 8 fingers and two thumbs.

Now that I have the rotary encoders working properly, it's time to think about the motor control circuit.  I have an Atmel AVR ATmega32 with three PWM outputs, of which I'll use two for motor control.  I'm planning a differential drive robot, that is, one with two drive motors, one for the left side and one for the right side.  I'll need forward and reverse directional control of both motors, as well as speed control via PWM. I have a couple of L298 H-bridge chips, so they'll do nicely.

I posted some time ago that some friends and I were building a Semi-Autonomous Quad-rotor helicopter for our Masters' Project at uni. Well, we've been working hard, and have finally built the actual helicopter (using a kit found at http://www.mikrokopter.de ). After most people had left uni last night, we found a large open space to do some simple test flights. I would say that the flights were a partial success, in that we now have to calibrate all the controls and work out exactly what each control is doing (I crashed the helicopter on its second flight!)

Sensing the living LMR community since 2008w43.

This is a photo of the encoder disk that I'm working on for the Hitari Tumbler robot chassis modification.

I'm looking at a Hitari Tumbler radio-controlled car chassis.  It has four wheel drive, with front and rear wheels on each side geared together, and to the motor.  There are, of course, two motors, for left and right side drives.  It's old, and missing the bodywork, battery and radio transmitter -- but we won't be needing any radio!

Hey folks,

I thought I would give you a peek a what I do for a living. I just finished this built-in for a HAM radio guy. The bead-board on the back wall is poplar and all hand milled while the desk and shelves are 6/4 and 8/4 African Mahogany. The finish is a hand-rubbed tung oil.

#8-o

 

This is an attempt to record the very edge to which an LED can be driven. A failed attempt.

I tried to post this as a component page, but it would not take embedded video...

The LEDs I tried are rated at 30 mA maximum. The forward voltage is between 1.9 and 2.1 V. I used a power source of 8.1 V  and a variable resistor in series that could range from 5000 to 0 Ohm.

Today I finally got a proper MCU and programmer, the missus bought me a late birthday present, a PicKit2!

 

 I have it hooked up, and running the initial demo, but have yet to figure out... well, everything :)

It all seems pretty straight forward, but I haven't dug myself into it quite just yet...

 

 /Fer

Things are being put on hold for family and friends this week, being Turkey day for us in the states, and I've been thinking about what I'm thankful for.

I know i haven't been around here long, but I am GREATLY thankful for you guys here. For Frits making the yellow drum machine and encouraging other's to try it, which first got me interested, Rik for the distractions and adding more crazyness to my final project, and everyone else out there that gave me encouragement and wild ideas.

Check out today's score!

A colleague gave me this linksys WRT54. The dreamed version with the lotta-RAM and lotta-flash. For free.

Sensing the living LMR community since 2008w43.

Im off to buy An RC car to create a robot first basic things (pre defined movement) then logic

 

Im will use an arduino Duemilanove  

A few weeks ago, Frits posted a blog entry explaining that we were working with Pololu to integrate their product catalog into our Components section. It took longer than expected to wrestle Drupal into submission, but at last the integration is complete, and as you may have noticed on the front page, all of Pololu's 300+ products are now listed as Components. Feel free to browse around -- the cool thing about it is that all of those components remain editable by every LetsMakeRobots user, so you can post comments, tips, opinions, etc about any component you want.

Okay I am trying to hook up the gear pager motor to test it so I write the code as below:

main:

high portc 3

wait 1

low portc 3

wait 1

goto main

I used the lead to test it and it seem to work the lead turn on and off every second but when I try with the gear pager motor its does not have enough power to move the motor. well the motor move but very slow so its not able to make a sound when it hit something.

 

Question:

After reading the new sensor wiki, I'm reminded of a robot I've been planning, that relies on temperture measurments. Basically I want the robot to act like a photovore, only looking for heat instead of light. Is there a way to sense heat at a distance (6-10 feet)? 

A fresh catalog shipped from Digi-Key.

Pardon me if I don't post around here for a while. I'll be busy with the precious.