Let's Make Robots!

quadcopter board for balancing robot - motor control assistance/ideas needed

I'm planning on using the Micro MWC Flight Control Board DSM2 ESC's X4 Brushed Integrated

Any propellor you want, as long as it's black

Today, on the IRC channel, 6677 posted this link:


where Parallax has open-sourced the Verilog code for their propellor chip.  This could be very interesting.

SRF04 vs. SRF05

I used the SRF05 on a previous robot I built a while back and it was pretty impressive. It was also a little expensive. I just got a deal on a box of SRF04's and got them but I can't really find the main difference between the two models.

Can someone illuminate me?

New to the site

Hi everyone I'm new to this site and would like to say hi it looks a very good site and lots of interesting stuff to do I am very new to electronics and would really like to learn about it and would like to know if any one knows of any good start up projects or information to learn the basics of electronics to progress me further on Thanks

sensing water flow in a pipe


I remember my dad yelling at my sister and I since we took long showers.  My sister had the hot water turned off more than once on her although I never did.

One motor is faster than the other?

Hi makers

Im trying to make my remote controlled robot working. Im using an Arduino UNO with the official motor shield R3. The controller is at this point a simple breadboard with 4 buttons on. The wireless communication is handled by RF links. Im using the Tamiya Twin Gear motors with the following DC motors. Im using the 203:1 gear ratio. Im powering both the shield and the Arduino using two seperated 9v batterys. 

Device signature 0x000000 while burning bootloader


So I bought 7 Atmega328's and burned bootloader's into 5 of them.However for 2 of them I get the following error:

avrdude: Device signature = 0x000000
avrdude: Yikes!  Invalid device signature.
         Double check connections and try again, or use -F to override
         this check.

I'm using Arduino Duemilanove as ISP and got the com settings,board selection and programmer settings correct.

Attiny Interrupts and communication

Hi everyone!

For the past few days I have been working on a "smart" servo. Basically, I want the precision of a standard servo combined with continuous rotation and low costs. 

The plan is: Put two brightness sensors on one of the inner gears and use them as a quadrature encoder to calculate the angle. This value is then sent to an arduino or directly used to reach a set position. 

What I have done so far:

I decided to use a HK15138 Servo from Hobbyking because they are about the cheapest servos you can find at this size.

Practical Uses of Artificial Neural Nets?

I have read over the theory behind neural networks and found open source code to help implement them in various ways.

I was wondering if any LMR users out there had put neural nets to any practical uses on their projects?  What kind of neural net did you implement?  For what purposes?  Was it worth the effort?  What problems in robotics do you think are well suited to neural nets?

Any interest in a temporary IRC Channel?

You all remember IRC right? No? It's basically the godfather of the shoutbox. Yes, it's still around. Since I'm probably the one who broke the SB I feel like it's up to me to do something about it. First step, admit you have a problem: we're a bunch of Shout addicts. Or we could all just go to the hang out. What is the level of interest here?

A small update on a project.

Hi guys o/

It feels like an eternity since I talked to you all :D But LMR is up and sadly I don't see the SB! Anyways, it should be up anytime soon as frits and blue and everyone are indeed working super hard on addressing the issue.

Max did it!!

he final broke the SB with MR speedo,:


picaxe and Sparkfun COM-11644

I am trying to get a Sparkfun COM-11644 working using a serial connection from a Picaxe 08m2.  I have tried every combination of 08m2 pins and commands and the display responds to nothing.

The connections from the 08m2 are Vcc, Gnd and c.4 as the serial pin.  I also have this post on the Picaxe forum and have gotten several replies all of which I have tried with no success and I have sent an email to Sparkfun technical support (no response yet).

The current code is here:

#picaxe 08m2


#com 3

setfreq m8


LMRnet AKA LMR IoT (Internet of Things) Data Service


AKA LMR IoT (Internet of Things) Data Service

Some days ago I saw in sparkfun news this particular one about their new Data Service (https://www.sparkfun.com/news/1527).
After that I asked Frits and Matt if we could host something similar on LMR's servers.

Get $10 Back for 3D Printer DIY Kit For Reprap Prusa Mendel i3

ICStation is into the 3D printer market now. And the first DIY kits is online for sell. We had provided with detailed installation info and debugging tips for learner/ hobbyists.

Help with Beaglebone Black balancing robot

Hello everyone, I want to start by saying this question post might become long and I hope you guys hang on and are able to help me. So here we go :)

First of all the robot is barely able to balance. Here is a video of the robot trying to balance. The problem seems to be that the robot is not able to reach the setpoint fast enough. This is a speculation so you guys give me your ideas on what the problem is also.


Right now I'm not really concerned with understanding the sound, but more with localizing it so I can point the bot's head at the speaker.

I was thinking of two cheap microphones with something behind them that would absorb sound. Then I could just focus on anything I could hear with both mikes and point the head until the sound is the loudest in both ears. If the sound is directly behind the bot, it should be possible to determine this by a very small microphone in the rear of the head.

Has anybody used a scheme like this?

Just a quick note

I know I've said this before in different ways. I know it's gushing, and I know it's kind of mutual admiration society stuff, but I don't care.

Ladies and Gentlemen of The Letsmakerobots.com community, you are the finest human beings I have ever been exposed to.

Thank you all for your continued participation here, from sharing your brilliant or modest or silly ideas and creations to teaching n00bs to lmgtfy or rtfm, or just goofing around in the shoutbox.