Let's Make Robots!

My two cents in memory of Lumi

Lumi meant a lot to me, and a whole lot more to this awesome community. Yesterday, I went rolling over past memories of Lumi - his time spent on LMR and other places around the world - and came up with a short tribute to this great person.

It's shocking, but life goes on. We all will miss you Lumi.

Noisy LM386 based audio amplifier

Inspired by this post from Salvage, I ordered a couple of gameDR Smack Talk for the XBOX units. The volume is way too low to drive a speaker directly, so I need an audio amplifier.

That led me to this post from Calculon320 on building an amplifier with an LM386. I breadboarded the audio amp, and it definitely amplified. However it also added a lot of noise. It could be cleaning it all up on a perf board would fix some of that, but it is very noticable.

Robotic Ants Farm

Well, Aniss1001 brought up in an other topic the idea of creating a swarm of robots. This reminded me of an idea I had 5 years ago, when I was in the States and building Lego Robots. Funny thing, a quick search on the net at that time revealed several similar projects. Also, my inexperience at that time with non Lego robots didn't let me put it in practice.

So, here's the idea:


Hi y'all, just joined LMR, fantastic site, lovin' it already . . .


I am a bit of a beginner to robotics, I mean I can program and all that, and make these things, but I know not how or why they work.

One thing I have been wondering is about capacitors:

When designing a circuit, how does one know where to place capacitors, or why to have them, or how they function in that position?

With this circuit in particular (from here: http://letsmakerobots.com/node/2074), why the caps?

those two in the top-right, why do they both need to be there?

Good Stuff to scavenge from a cell phone

I just ripped apart an old Samsung SGH-T739.

Picture of Samsung t739

I was planning on using the vibration motor that is used for silent mode. As long as I have this thing torn apart, I'm curious about your ideas for what else might be good to use.


Which Wireless Camera you Recommend?

Hello LMR!

I recently came up with the idea of making my own surveillance robot.

From what I´ve seen until now, all of them have a wireless camera built-in to allow remote control or just a view from the vehicle.

So after seeing some of you have used wireless cameras in your projects, what would you recommend?

I´ve done a little research and came up with this one (I don´t want to waste more than 30$ on one)

Multicopters building a wall


It'd be fairly simple to adapt the thinking to less hard to work with robots, I think it's inspiring :)

feasibility of DIY wireless headphone kit

So, I was searching the market for what my wireless headphone options were and got quite disappointed.

As it seems, wireless used is either IR, RF (on the FM/UHF band) and Bluetooth (also 2.4Ghz seemingly working in the router's norm).

IR ... needs line of sight, small range...
RF... prone to interferences
Bluetooth... small range
2.4GHz... some reviews said they interfered with the home wireless routers


solar powered robots

Hey guys I have a small problem I can't get my head around (I only have very basic electronics knowledge) and was hoping someone smarter than me could help.

I am looking to power a small robot by solar panels directly driven by the power generated from the solar cells. I understand to do that you generally need a few volts more than the battery that is usually powering said robot due to various reasons. 

Getting the most from an LED

Hi guys. I have recently written the walkthorugh on how to transmit serial data with an IR led and it works fine. Now to the next step: i want to achieve the highest range possible with my LED, without using external aids such as lenses. (that is: only with electronics).

Sensing servo feedback


I'm new to this forum, robotics, electronics and microcontrollers, however I have been programming a long time and I'm currently studying computer science.

I recently bought an Arduino board with the purpose of making robots for experimenting with my special interest: AI.

I wish to build a walking robot and experiment with varios ways of giving it a nervous system. So I will need to find a way to get feedback directly from the servos, thereby being able to read the amount of stress (load) they experience at a given time.

Navigation with (2) sonars Update 2 (with data)

*****Update 2.16.10*****

Got some data to start thinking about, guys. My thoughts of getting nice, even packs of 4 or 5 is a little out the window. To be honest, I tried to forget that I could see where the robot was facing and tried to make a decision where to go based on just the readings. I couldn't . Please note that I was seeing the readings on a LCD so left was above right not in a straight line. --Now that I think of it, I have no idea why I didn't line them up as it is a 16x2 display. Huh.

All readings were taken L to R

Thinking of XBee Communication, a few questions before I jump in

What I intend to do is create a wireless link between my robot and my laptop, for remote serial programming, and remote control.

I posess a PICAXE 28X1 project board that i wish to connect with an XBee module.

From what I've seen in http://www.rev-ed.co.uk/docs/axe210.pdf an AXE210 is suggested. On page 9 however, we find that the XBee is only connected to the AXE by three pins: two inputs and one output.

Maker Faire 2012

Let's go to Maker Faire!

Organization and volutneers

I plan to go to the New York event for certain.