Let's Make Robots!

Parts Prices (In US Dollars)

Here is the analysis I have done so far. I didn't look everywhere, but I did learn 2 things.

  1. You can't buy everything from 1 place
  2. It is cheaper if you buy from outside of the US on some parts

Here goes my summary: (For all intents and purposes, when priced in £ double it for US dollars. It is a bit less than double, but after your credit card company charges a fee to convert the purchase it will be close to double given the current rate of exchange on 5/7/2008)

Starter Pack (Picaxe 28 with USB cable)

Servo problems

My Picaxe 228x1 arrived today with the servo upgrade pack. I have followed all instructions but can't get the servo command to work. It appears to be trying to turn clockwise past the stop - i.e. it turns all the way and then buzzes. I can get it to move ok with pulsout commands so I don't think that the servo or any connection is fundamentally broken. The following is my program - the servo 0,150 is the command that isn't working as expected (any position I give seems to give the same result)

Anybody got any ideas what I've missed?

 

Advice - PICAXE to PICAXE IR

Guys-

The goal is to allow 2 PICAXE chips to speak with each other via IR.

What receiver and transmitter have you all had success with. Where can I purchase? (links?)

Thanks all.

Software PWM

I was hoping to avoid wrighting my own software pwm for the pic but it looks like i've arrived there.  the motors and tracks I hot glued toghther don't drive straigh so the only way I can think of fixing it is to use PWM to slow down one motor.  I know I could use the one hardware pwm to slow down just one motor but thats going to be used in the future for somthing else so I have to create the pwm myself in software.

Help with 555 circuit.

Well, I have got the 38khz distance sensor working in picaxe form.

Here

Here

Now I am trying to wire-up a stand-alone unit with a 556. Now I know this is a RTF(data sheet) moment and I know the resistor/resistor*cap/2 (or whatever) equation, but the final circuit is still above my head. Are there any of you circuit guys out there that can do a little drawing for me? Maybe with a couple pots for fine adjustment? I plan on the final output going into a picaxe using the pulse-in command.

Thanks in advance.

n/a

TENET TECHNETRONICS is now an official Distributor in INDIA for Arduino Boards

TENET TECHNETRONICS is now an official Distributor in INDIA for Arduino Boards an open source Electronic Prototyping/Development Board, an easy way to procure boards in INDIA. These boards will help your  electronic ideas to become a reality. We also host a range of electronic boards - Micro Controller, VLSI and Embedded boards. We host a wide range of electronic components to cater your needs.

Boards we currently distribute
    Arduino Mega
    Arduino USB/Arduino Duemilanove
Arduino Pro
Ethernet Shield for Ardunio

Picaxe PWM and servos

I have tried using picaxes PWM outputs on 2 robots now with limitted success. The biggest problem I have is that the PWM frequency although adjustable is very high (typically 16KHz with a 16MHz resonator). This causes the windings of the motor to have a much higher impedance resulting in poor torque. When I use the setfreq command to drop the clock speed very low (500KHz) then I get good torque even with a low dutycyle but the processor is so slow it is almost asleep.

Big choice of servos in Europe

Hi,

I'm making a robot arm, and I need 1 shop to buy all my servos from (legal reasons).

Problem is, the shop has to have all the range from powerful and durable high-torque servos with full ball bearings (about 25 - 30 kg/cm), to lighter standard, to even some very lightweight mini servos.

So far the shop with the best choice is http://www.active-robots.com/products/motorsandwheels/servo-index.shtml, but I would be very happy if someone coined me some more or better options :)

Hello! I'm new here

 

Hi there. I have seen a few videos from this website. I've even been told a few time to sign up, so here I am! :) Glad to meet you all! Lots of fun projects on here. I've been looking through the Robots and Blog area, some real neat stuff.

I'm a robot builder also, sorta, kinda. I spit out new ones often, so I may not have time to post them in the Robots section. But I really like the active forum here! I'll probably be around often. 

Here's a few links to some of my robots if you're interested:

Bring Back the Challenges

As you all looked at LMRs home ribbon some new things have been added. However, SOMETHING IS MISSING. take a guess. If you guess challenges you are correct. What ever happened to that? Why did they take it away? Who knows. I think the challenged brung out the true creativity that makes this sight AMAZING! Sure the prizes where nice, but nothing beat the thrill of either winning or judging other peoples robots. Should they bring the challenges back? Give me your thoughts.

pretty cool fountain

Found this while surfing the interwebs. Thought it was interesting and I'd share it with ya's folks

It uses some common components(well, aside from the uv leds that aren't available at your local hobby shop)and a pic.

 Now just makes me wonder how to do something like this...code wise.

http://cre.ations.net/creation/the-time-fountain

Mini Makers Faire - ShenZhen, China - LMR will be there!!!

Much to my surprise and delight, DAGU will be attending the Mini Makers Faire in ShenZhen. We will also try and setup an LMR stand. I know this is short notice as the Faire is only 1 month away but I would like to invite LMR members to attend or at least send in one of their robots.

Links to photos and videos will also be welcome. I will get the photos printed and use them as a backdrop. I will have at least one large computer monitor playing LMR videos.

Optical Encoder giving variety of results

Hello,
I have a QRB 1114 and have done a little experimenting with electrical tape on my wheels.  I "thought" that I had this working before in a different setup, but maybe it was not working "correctly" before.

Nano v2 Digital Storage Oscilloscope

 

Anybody got experience with this mini Nano v2 Digital Storage Oscilloscope?

 

http://www.seeedstudio.com/depot/dso-nano-v2-p-681.html