Let's Make Robots!

Blogs

Update on my status with BeagleBone Black delivery

Well, almost a month ago, Mukund showed me the BeagleBone Black over on facebook. Then, I was considering buying a Raspberry Pi and a Freeduino Uno, and since the company was located just 30kms from my home and had next day shipping facility, I was pretty happy with it. But Black had an appeal to me. It was both a Raspberry Pi and an Arduino Uno and better at it than the combination of both. All this and the fact that it was cheaper at that time, I persuaded both myself and my parents to buy it. Then started the problems

Sad story about Chopstick Junior and Campus Party Berlin 2012

Well, let me begin with an introduction of the robot and the event but you need to promise me to read it to the end...or just the end if you don't have time.

Beginnings

 

May 19, 2013

I am building a robot controller board using a Zilog Z-80 processor.  For those who don't know, the Z-80 was one of two major CPU chips in the late 70s and early 80s, before the IBM PC ruined ruled the world. The other was the 6502.  I hope you will follow along as the project progresses.  It will be fun.  Why on earth would I want to do such a thing?  Glad you asked.

Help with steering linkages (Not a robot)

Hey guys, I know this is not a robot but I could really use a second set of eyes on this one...

Variable Power Regulator Mystery DAMMITDAMMITDAMMIT!!!!

I suppose I shouldn't be complaining.  After all, the circuit works:

...and more or less this (the cap straddles the gutter on my board  but Fritzing is limited...)

There's no connection to pin 3, which is "output" supposedly.  Yet it works as a voltage controller-from 18v to 3v-12v (range.)

Raspberry Pi is not a pc :) And neither does BBB or Olinuxino

Hi all!

OK so this is not a rant or maybe it is but here we go. 

Raspberry PI is not your common PC (and this applies to all little ARM based boards popping up lately).

Try running a fullfleged linux distro on it and it will crawl to a slow moving beast, and by fullfleged Linux distro I do mean all those things like Raspbian, Archlinuxarm etc. These things are just normal distros recompiled for ARM.

Optimizing the Jansen Linkage

 

Still tweaking my optimizer for Jansen (Klann) walking linkages. I started posting some of the more promising optimizations at http://boim.com/Jansen/Favorites

Flat, optimized Jansen Linkage

Mini Robotic Shield

 

Make your first robot is a fun thing. Forces you to use creativity to solve those small problems. But not everyone has the space, tools (simple as it may be) available or sufficient knowledge to make your first robot from scratch, it makes some people give up in the early days ... fair will then prevent them to have fun as we make our robots? NO.

A silly really small co-operative kernel ... in case you need one :o)

 

so ... one of my friend needed a little help with concurrency so last weekend I chopped out one silly little co-operative kernel for his arduino applications...

I built many of those little kernels for different cpu over the years.

they are usually simple ( not time sliced ) and they work fine with ucontroller and few cooperative tasks.

this silly one is as much thin you can go, only simple tasks( with their own stack) and semaphore (with P and V) , all in C, and using for context switching setjump() and longjump().

Looking into Klann linkage

Started looking at Klann linkage.  Reversed some dimensions from the patent.  They seemed overly "symetric", likely suboptimal.  I may want to look at running an optimizer on that basic linkage.  Here is an animation of the Klann cycle, done similar to what I have done for Jansen.Animation of a step period with a proposed Klann-like linkage

Would you ARM yourself? (Or, Who wants a slice of Badj-berry Pi?)

While the parts for what I'm considering aren't here yet, they're definitely a possibility. With all the chatter about the new Beagle and with everyone already having an RPi in hand it seems, to me one of the next logical steps (if we are to take PicAxe and Arduino as a template) is the hobbiest making his/her own Linux SBC. I suppose if you're Patrick McCabe and have a reflowster, it's not out of the question. However, God what a pain in the ass that would be.

Issues with Jansen Linkage

There are two main concerns I have with the Theo Jansen linkages, which have shown up in rough prototypes.

basic drawing and node naming for main linkage

Theo Jansen Walker

I'm starting work on a Theo Jansen linkage walker.  I'm keeping a copy of my project notes here

My prototype has a vulnerability with the knee collapsing toward the fixed center node. Has anybody else experienced this? Any suggestions? I have code for solving linkage geometry, plotting, and .scad models for prototype 3d-printed linkages.

Here is an animation of one side of my proposed 8-leg walker, animation of Jansen trotting motion

My trip to Xinjiang China

My Company was invited to the city of Karamay in Xinjiang China to demonstrate our robots at a Science Festival. Xinjiang is in the North West corner of China and borders a number of other countries. We had a 5 hour flight from Guangzhou (formerly Cantong) to Urmaqi and then another 1 hour flight to Karamay Where we were met by a lovely lady who's English name was Jenny.

Click on the map below for a hi-resolution image.

Codemotion Berlin 2013 conference

On 10-11 May 2013 there will be a Codemotion conference in Berlin. Citing their web-site: "Codemotion is an innovative tech event engaging developers of all languages and technologies in presentations & conversations about: mobile, web, Makers, startup ideas, sustainability, game development and creative coding."

A stumbling bumbling attempt at a 3D printer

Well this is my attempt a building a 3d printer, I am blaming TinHead for the whole thing, perhaps with some blame beeing focused on CtC as well and let me state here Chris and Tinhead were both a great source of encouragement and help in this on going project. The whole journey started with my seeing Tinheads build of bumble bee  http://letsmakerobots.com/node/32879

Wireless/Zigbee for PIC Micros

Back in 2009, my professional work involved leading the firmware project of a low power wireless network of sensors collecting temperature and humidity data. Wireless gateways accumulated the information and sent to a data center over the internet. During that project, I fancied my own Zigbee network for my robots and setting up a network of home monitoring sensors. I eventually bought some Microchip MRF24J40MA modules (which is a completely different platform than my professional work).

A hexapod for my son to ride on - a big experiment

After seeing the weblink by bdk6 "inspiration for Hexapod builders" I was inspired. The video is of the "Mantis" turbo diesel all terrain hexapod.

Ok, I cannot afford to build a 2 tonne turbo diesel hexapod but I can build one big enough for my 8 year old son Shi Sen to ride on. My plan is to have almost the entire robot laser cut from 6mm plywood.

Why we don't want to be sucked into another universe!

Well, it's about time that somebody (me) stopps the danger of the words found in kariloy's posts. 

As some LMRians already mentioned, we get sucked into another dimension or universe by spelling out them loud.

Now...kariloy, step forward, be a man and give us some evidence that we are all wrong and there is no danger to say those words loud. 

We want a video, you saying the word which is found in your last post...

YAPBATOINTMBISHABOWIS AIWPEURITJOS

YellowBot Source Code

I have not put togethger documentation for my Bots code. The code is evolving too quickly for detailed up front documentation. I would like tos tate that a primary goal of doing this Bot was to help me learn Object Oreinted Programming, as well as get me used to programming again. it's been 20 years since I've written something more than a simple shell. python or Perl script.

Thus I will warn you this code is chocked full of redundancies and inefficiencies. Bear with me, an old dog is learning new tricks, it's just taking time :) 

Mini Maker Faire ShenZhen 2013

Maker Faire has once again come to ShenZhen, China thanks to Seeed Studio. Unfortunately I was only there for about 9 hours on the first day. I'm sorry I have not documented this very well, I was at the DAGU table most of the day. I have now added photos from my friends camera's as well.

I think Maker Faires, even Mini Maker Faires are something that cannot be explained with a few photos and videos. You really need to be there to truely appreciate them.

IR Sensor Info

IR Sensor Info

IR distance sensor - Sharp GP2YOA21YKOF
This sensor has a range of 10cm - 80cm. Approximately 4" - 32".
The sensor outputs an analog voltage based on the object distance. The
voltage ranges from 3v for a near object to .4v for a distant object.


The IR sensor is mounted on a a servo that sits on the rotating base.
This gives both an X and Y axis movement to the IR sensor. The base
rotation will sweep the sensor back and forth, across the width of the

arduino code

im working on the ankle servos, so im just using the example sweep, an i have them zeroed at 90 deg. I can get it from 90 to 180 an back but i cant get it to go 90 - 0.   

 

 

 

#include <Servo.h> 

 

Servo myservo;  // create servo object to control a servo 

 

 

int pos = 90;   

 

void setup() 

  myservo.attach(9);  

 

 

void loop() 

Everything you never wanted to know about two wheel drive.

Platform Drive Control.

This platform is driven by two wheels mounted so that the wheel axis
is just off center. There is a small caster wheel mounted in the 'rear'.

At this time there is no speed control feedback.

Maneuvers are accomplished by independent but coordinated control of
each wheel motor.

The drive motors are servos that have been hacked to continuous rotation.
The servo hack involved pulling the feedback control board and pot as
well as cutting the stop on the main gear. Thus the servos are converted

Yellowbot, the circuit, or I love Fritzing.

While messing with my Arduino I found the circuit diagraming program Fritzing. I really love this program, it makes docummenting breadboard circuits increadibly easy.

You can get the software from their site: fritzing.org

YellowBot, project overview.


The platform should be able to independently navigate our normal household
without getting stuck in/under something or falling down the stairwell.

This project has been down using previously purchased kits and very little
additional hardware. All of this is done using an ArduinoUno.

The platform drive system is a two wheel setup using a frewheeling cater wheel
at the rear.

The platform has been setup with a breadboard and mounting for the Arduino.

The Arduino is powered by a 9v battery.

About a weeks worth of content

Since bird and Kariloy have both come up with automated solutions to the shoutbox image posting process, I've decided to join the flood of efficiency and just funnel a week's worth of stuff into one link. Someone created the gallery for me, so why not? There are some old favorites and plenty of new shakes. Enjoy the Knock knocks! (Oss, you might just want to bookmark this page in case I get sick again.)

Need help controlling Traxxas ESC and Servo with Arduino

I'm working on an autonomous ground vehicle, guided by a U-BLOX Neo 6m GPS Module, and HMC5883l compass.

The ESC connects to the 7.2 NiMH Battery pack and is supposed to be connected to a RC receiver with a standard 3 wire servo cable, it also provides 6 volt regulated power from the same cable. Because the power is too high for an Arduino, I used a separate 5 volt power supply for the rest of the electronics, except the steering servo. Using a separate power supply makes the ESC and servo uncontrollable, creating a lot of jitter.