Let's Make Robots!

TLC5940 anyone?

Allthough these chips are actually called LED drivers they are apparently capable of controlling servos...up to 16 of them :) There is even an Arduino library available for doing so. Pretty cool stuff. But I was wondering if anyone has any experiences with this? If yes then I'd like to know more about it. If not well then consider this a tip to keep in mind the next time you run out of servo pins ;)

Basic electronics explained in cool informative way (Schematic and IR Light Update)

Basic electronics explained in cool informative way by Colin of Makezine, including simple electronic experiments.

Videos as follows:- (links are URL)

PWM Question with PICAXE 40x1

The 40x1 has 2 PWM pins. I have the code pwm 1, b2, 1 but I think I need to tell the picaxe that I want to use the pin as PWM since it can also be an output or input pin. Any ideas?

The "Uncanny Valley" of robotic appearance

I came across this Wikipedia article about how humans can have a negative reaction to robot's appearance as it begins to approach a human realistic level.

laser pointer and a 38khz sensor

would it be possible to make a laser flicker at 38khz?

I was thinking; if I had a modified laser that gave me a red dot that pulsed at 38Khz. If a robot was made to go towards a 38Khz beacon...

I thought this might function as a intuitive remote control.

The robot is programmed to do whatever, map its surrounding, search for metal or filming the girls gymn locker room. But when the laser is pointed anywhere in its vicinity it'll start following the red dot until the laser is switched of again. then it will continioue its original task.

A few 130 size 6v motors to swap, direct replacement for tamiya 130 size 6v motors

I have a few size 130 6-12v motors to trade. If you are using tamiya products that use the 130s, and want to use a L293D or it's equivalent. I'm looking for all kinds of things to trade. Email me offline to discuss things. If you don't want to trade they are $2usd each + $5usd domestic only. International orders please email for shipping quote.

 

Mech 

servos, ir, or proc speed causing issues with serout on a picaxe?

I'm a little confounded with an issue that I'm having. The setup I'm using is a Picaxe 08M with the following components connected, BT tranciever(uses two pins for i/o), a servo, an ir receiver, and the latest addition, a serial lcd display(connected to pin 0). 

Basically all of the components work except for some funkyness with the serial lcd. It appears to get garbled data when I use it on the axe with the above mentioned components.

NiCad vs NiMH batteries

I wanna buy a charger and some batteries so I've been doing a bit of research on the different types. However the information I found is somewhat confusing and outright contradictory. And in any case I'd like to hear about the experiences you guys have had using NiHM and/or NiCad batteries...

Which would be the better choice? Pros and cons?

Need help "translating" a C program to work in Arduino

I need an expert in C/C++ programming to help me translate a fairly complex piece of C code into Arduino specific code, perhaps even create a library. The original author of the code can't do it, but we have his permission to do it, as the code is released for hobby use only.

 The code is very interesting for many Arduino based robots, lots of people will benefit if we can make it work.

Please reply here or PM me if you're interested. Thanks. 

LMR Planned Downtime

LMR will be down Wednesday 11 Nov. 2009 at 9pm PST (Pacific Standard Time, GMT -8) for some updates. Expected downtime is about half an hour.

Yes, this has been changed already ;) Due to the

Mr. Basic Challenge 2 ( autumn 2009)

challenge ending tonight, I don't want to mess up anybody's contest entry.

UPDATE: Done

Sharp GP2D120 vs SRF05

Hi everyone,

I just completed the "Start Here" robot. I used a Sharp GP2D120 for the eyes and I used Fritsl's programming for the "Start Here" robot. I do not have any experience with programming but once I get this robot done then I will be able to learn more.

I have noticed that the robot is very slow, i.e.: It drives a little forward, then stops, and takes a reading, repeat. I assume this is because the robot is stopping to take a reading. If that is correct, then the SRF05 is better because it can take readings without having to stop the motors?

Where to put clamp diodes in a SN754410 motor controller circuit?

After a quick Google search, I couldn't find a schematic for the SN754410 with the clamping diodes. Instead I found this document which uses the L293. Could I use it to build the motor controller with the SN754410? What changes would I need to do to use one motor per IC to double the max continuous current? I have some 1N4006 diodes, could I use them in this circuit?

 

motor_1A.jpg

 

Salvage from a CRT TV and its remote.

A TV has just died (too dramatic a wording?) in my family where it went funny colours leading up to its not turning on. I'll need to check the plug fuse for them but it sounds like the CRT died after many years use. Rip it open time!

How can i measure the thickness of ice

How can i measure the thickness of ice.

Is there an easy way either with IR or Laser to do this.

Why :-  It would be far safer to send a robotic car across an ice lake to test if the ice is thick enough for skating - or even in a rescue type operation.

Any answers however lateral and crazy welcome.......

Encoders for servo mounted wheels

Picture_004.jpg
 
 
I have 2 questions, 
 
- First, when using a C-stamp (programmed using MPlab) is it possible to track the movement of a continus rotating servo so that I dont need to add encoders to know how  much the wheel has turned?  
 
This is an example of coding that makes 2 servos turn(if it helps):
 
void goforth(BYTE lp, BYTE rp, WORD t)
{
  WORD i;

Conflict with PWM2 output and osc input (PIC)

this is some data i got from the datasheet of the 18f252:

RC1/T1OSI/CCP2 

RC1 

Digital I/O. 

Power toool motors - worth scavenging?

It's been a while since I spent any serious time at LMR, or indeed building robots. A pressing need to totoally renovate a Victorian house has taken priority so that I can generate enough money top pay the mortgage interest when rates rise again !