Let's Make Robots!

Max713 NiCad/NiMH smart charger.

I made a battery charger with some free samples of the maxim max713 chip.

Maxim home page.

Chip details.


Search for samples.

Robot Localization - So a robot really knows where it is

Robot Localization

Making a Robot know where it is

I started looking into localization for use with sandbot but there have been many other things that conspired to prevent me progressing with it. I put it here as a placeholder and will come back to this when I have more time to think about it..

Homemade wheel encoder

Basically I just printed out one of these (laser printer recommended):


...And attached it to a wheel (double sided tape recommended).

Then I hooked up one of these (a 2$ IR sensor: QRB1134):


...And attached it to the motor pointing towards the wheel.

SSS - Servo Suspension System

This is my first experiment with the MakerBot. I am totally thrilled with this machine!!!

SSS (servo suspension system) is designed to support standard servo motors and act as a basic suspension. It is still a work in progress and has not been tested yet.

Will update results as soon as possible (still waiting to have my lab back).

I would like to know everyone's opinion on this  :)

Don't program your robot.. Teach it!

(Update: Some time after writing the below, I made this, that may interest people doing navigation with Picaxe)


How to make a robot do complicated tasks & "act alive".. With ease..

Here is one guys humble input - I am sure you all have your own ways of programming. Just take it for what it is; My personal thoughts, use what you can :)


Arduino Wavefront Algorithm

First Up... If you want to find out what Wavefront Mapping is all about head over to the Society of Robots Tutorial. It has a great wtite up and its where I first learnt about it.


Basic's done, So lets talk about Map size limits.....

The Arduino 2560 & 1280 both have 8k of SRAM (where the map is stored)

I'm using an array of Int's, each Int is 2 Bytes, so max size would be the square root of 8k / 2.

8192 / 2 = 4096

Sqaure Root of 4096 = 64

Free Range Robots (IR Beacon) **UPDATED**

**Update 4.14.09***

OK, when you watch the video... 

First of all, it is like, 5 minutes -sorry. There is a point though promise, and that point starts at about 3:40 or so. Now, I can't stress enough, the code is wicked chunky as it was written in about 10 min. It is all "bang-bang" and not proportional at all. The final code should be about 10x faster, much more accurate with a lot less trial and error. For now, this is just proof of concept and indeed it has been proven. 


A Simple Way To Give a Bot Motivations, Decision Making, Better Autonomy

Recently, I got to thinking...there must be a better way to program autonomous behavior (than my previous attempts).

I thought about people, people have various motivations, why shouldn't bots?  When people get hungry, they eat.  When they get curious, they look around.  When sleepy, they sleep.  Surely bots have needs and priorities that should influence their behavior.

Quadcopter begins


Well i finally went through with it and started on a quadcopter. I will probably just stick to doing RC with it but who knows, maybe one day i will make a quadcopter UAV.




LMR logo kit

Hi Folks,

You've all discovered the new LMR logo:



Fritsl had the very good idea of a logo kit, available to everybody.

Here it is http://letsmakerobots.com/files/LMR_logo_kit.zip

It contains various sizes of the logo, in color, grayscale, black/white   (biggest is 4000x1000pixel)

Swarm Robots - Brainstorming (Football robots)

This will be a note for my just started team project "Swarm Robots".

This project will take place in our hackerspace Shanghai "Xinchejian". it will be a team project where every member can join and contribute his/her skills, ideas etc.

In this blog I will ask questions and write down solutions, ideas, goals and everything else what is related to that project.

So far that's the initial idea:

RF link TX/RX 434 MHz = lessons learned and then some

I'm trying to build some sort of RC transmitter using the 434 MHz radio link set. Sometimes called Easy Radio, but not by SparkFun. Edit: because they're not the same thing!

I am setting this up on a breadboard with a Picaxe 08M and two potmeters as inputs. The two ADC bytes are combined into one byte. The one byte gets transmitted.

ATtiny servo control


After a brief discussion with fellow LMR member Maxhirez, about his Hedwig robot,
it seems as though there isn't much support for servos in the ATtiny family of
microcontrollers. After fighting with the 8-bit servo library I found HERE that was
supposed to make it as easy as a standard Arduino to add servos to an ATTiny project,

Arduino Shield for building robots

I've been asked by a few people from different places if there is a simple way to use an Arduino to build robots. I explained there are ready made boards like Roboduino, Romeo, Motoruino, etc. that can be used. Or a custom compatible board. I told them that I went both ways, mostly because Roboduino doesn't have an H-bridge onboard, so I designed my own customizable board, R-Dev-Ino. Usually people are puzzled with all that information, as they have heard about Arduino, some have used it in art projects or so, but did not hear about the other variants. Seems complicated...