Let's Make Robots!

DC motors from DAGU

I'm putting together an order at DAGU. But I need to be sure about one thing. The DC motors (items 12 and 13 in the LMR price list), are they GEARED motors? I presumed they were, but then I mailed Claudia and I asked: "Item 13 (dc motor) in the list: Are these motors WITH gears?" and got this answer: "The DC motor will not come with gears". However I think she may have misunderstood my question cause they do look like geared motors....

Regarding Robots which uses GPS tracking...


I am new to this forum, and I want to submit a project to school on Robots.

Aim: To feed the destination address like NMEA code to the controller and it uses GPS receiver to know its present position and compare with the destination address and move to the destination address specified by using stepper motors..

 Can u pls guide onthese..

How to decide about stepper motors and controllers I thought of using ARM7 whether its OK or not..???

PLease guide me...

Looking for a LCD counter

Hi people, does anyone know where i can find a cheap lcd counter (as described on page 19 of the 3rd picaxe manual)? Ideally with backlight 'cause the goal is using it at night...

(and yes, i searched on google but with no luck...)






Join the LMR CAD Team! We (Krumlink and -Gary) are a group of Experienced CAD users capable of designing stuff in CAD! We use the STEP file types to share files between all (Autodesk and SolidWorks) software. Put your name in below, and begin collaborative CAD design!


This post will be improved upon later, but we will post our collaborated CAD drawings, etc

LCD pin names

We have this LCD and we are trying to connect it to the Arduino. We are having problems with the pin names. Here's what we have so far:

Vss - ground

Vcc - voltage (+)

VLc / Vee - we believe this one is for contrast - confirmed

RS : register select

R/W :read / write


D0-D7 : data pins

VB+ : LED positive

VB- : LED negative


LCD - V.Smile Pocket

Would it be possible to make this thing work with a microcontroller? It is from a V.Smile Pocket (handheld brainwash learning station). The V-Tec site says it's a "full-color LCD screen with 320 x 240 resolution". That's all I have.

The white cable is what connects it to the main circuit. It has like 25 metal points/pins. 

[My cell phone camera is not so good]...



splitting voltage

Greetings Earthlings,

Calculon's current project involves 2 12v motors (he's in the big-time now :)) but he'll probably have to use an 18v battery. He wonders what is the best way to power the brains AND the wheels from this.

Should he use a 12v voltage regulator and a 6v regulator at the same time? Or is there a better way to divide up the voltage?

Microservos from DAGU?

I was just wondering..does anyone have experiences with the 8g microservos from DAGU? I'm talking about item 19 in the PDF found on this page. How do they perform compared to other generic servos of similar size like HXT900 or TowerPro SG90?

How to connect SPDT relays to control a motor's direction?

I have two SPDT relays, but I don't have much info about them: [a: side label] & [b: top label]

a) 8A - 250VAC

    10A - 28VDC

    DC - 5V

b) Coil: DC 6 9 12 24V

    Capacity: 5 8 10 15A 250VAC

I also have some transistors like this one, some old circuits with various types of resistors, and some diodes too.

How should I connect these things to make a motor change its direction?

Trouble when counting encoder pulses

I have a pair of surplus Faulhaber gear motors with built-in quadrature encoders. I have a motor controller with Arduino and a SN754410 H-bridge. The channel A of the encoder is connected to an external interrupt on Arduino (INT0 and INT1) and the channel B is connected to a regular digital pin. The interrupt is set as Change and the ISR checks the logic level of the interrupt pin and then the level of the digital pin to determine if the counter should be incremented or decremented (depending on the direction of rotation).

Serial oscilloscope

Hi guys,

I'm currently programming a software oscilloscope based on C++ and DirectX, thus the performance is very good. It works directly off the serial/COM ports. I was just wondering..is anyone else interested in such a thing?

I'm programming it for my Arduino BUT it should be able to work with Picaxe(or anything else) too. It's not gonna be a fancy pro application, but it works pretty damn well :) For now it's rather limited since it only accepts 8 bit values...well for now...

Virtual Keyboard (Reads ASCII data from COM port)

Here is a program that reads Serial data, ASCII, and turns that into keyboard strokes. Works with the Serial.print command in the Arduino IDE. (Not sure how it works for Picaxe!)


About halfway down.. kind of hard to see the download link.

Using GPS via Serial Connection!

Well, I found out that Maplin had a really cheap GPS module that supports UART (Serial) at 38400 BPS. I'm still waiting for it, but here's what I have so far!

Here's the unit, and specs: (unit was JUST discontinued, so won't be able to find much info on the device itself)


How to click a relay with a low signal?

I need to click a relay when a signal goes low. I have a couple relays on Walter, but they all click when signal goes high. These are pretty straight-forward, just a simple 5v relay, and a 2n222 NPN transistor to click it when a data-level signal goes high. --No Problem

xmos progess anyone?

Calculon recieved a note from his lovely postman indicating that he will get it on monday. :)

From what he's been able to read, he gets the impression that almost all mechanics/electronics (motor control, LED control, adc, sensor-type switches, and so on) must be handled by other ICs that communicate to/from the xmos board with serial ...

Is that right, or is there something he doesn't understand yet?

LMR's search engine

As everyone here is well aware the LMR search engine is fu^H^H broken. I am working on figuring out a replacement that works with what we already use, (PHP, MySQL) doesn't require me learning another langauge (Java), and could actually be suited to providing additional functionality (faceted search of components). Fun stuff, and it is my main LMR priority right now. That doesn't help you guys much though, so I figured I'd make a post about other workable options in the meantime.

My ICS28 IC Sockets: For you!

Well, I accidentally ordered the wrong 28 pin IC sockets. These are the wide type, shown here: http://www.futurlec.com/Sockets/ICS28.shtml . What I need are 28 pin narrow sockets! Woops. I don't use any chips of the 28-pin wider configuration. I'm in the UAE so I can trade with anyone in Europe or Asia at a pretty low cost I think. Anyone up for tradesies? I've got 30 or so of these guys. If you have some extra 28 pin narrow sockets, fantastic, if not, whatever!

 So who wants 'em? :)


Voltage Regulator

when i use the lm7805 oddbot's voltage regulator...the motor runs slow and the servo jitters...i test my voltage regulator it says 5.02V .85A...i used a 9v battery...how come its slower when i add V2??and cant run other programs that i coded

voice recognition robot

hi  i am planning to do an robot controlled by voice..can any one help how do i start with..its enough if i can able to control with some 5 or 6  voice commands..pls suggest me..