Let's Make Robots!


RF shielding

The encoder wires on my Rover 5 seem a little short.  The ground wire seems to be a shield around the other three conductors.  Also, I notice that the pin groupings on my 4 channel motor controller have a ground.  Makes me think a little.

Acoustic Noise Reduction

So in another forum I explained how I was using power screwdriver motors to move my rocker bogie suspension system. So I was wondering if you guys had any ideas on how to dampen the acoustic noise(not the electrical noise) coming from these motors. They use planetary gearboxes which I know are notorious for being loud but I need the torque that they provide. I was planning on using some sound proofing material to dampen the sound but I was wondering if you had any ideas. I know it is kind of a weird topic but thanks for your help. 

Stepper motor holds at full current and makes noise, smooth otherwise


I have the following:

EasyDriver stepper motor driver

Bi-Polar stepper motor 6 wire

I am using Red/White and Yellow/Black, which means I'm using half coil.  My understanding is this allows me to use the full current (and presumably have more holding strength).

Lots of strange Sharp IR Noise…?

Hey everyone. So, I just finished my first robot in a few years, my first being 2 1/2 years ago. This one is a lot more complicated in terms of hardware since I made my own boards and all, and have 5 ICs in one circuit. I'm done with programming and everything runs well but there's one ongoing problem with my Sharp IR GP2D120 sensor.

Filtering Sharp IR sensor's noise on power rail

I have some problems with Sharp GP2D120 IR distance sensor on my next robot, Hammer. Sharp seems to cause noise on the power rail and the noise gets to LM386N-1 audio amplifier making really annoying "ringing" from speaker. Or at least this is what I suspect. Check the embedded video for a sample of that noise (or go here: http://www.youtube.com/watch?v=WIQ0qY6gFpQ). The video starts with Sharp disconnected and then I connect and disconnect it couple of times.

Emits bright light and loud noises =D
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How to reduce servo noise?

So it has come to my attention that like motors, servos too need capacitors over the power and signal lines. Well my question is exactly what value capacitor and on what servo pin. I looked online and could not exactly find it, maybe you have a link. I dont know if it is specific to what servo you have but here is the link to mine http://www.hobbypartz.com/topromisesg9.html

Practical question about servos and capacitors

I have read in many places on this site about using capacitors to reduce motor and servo noise. I am now using 0.1 uF capacitors across the leads of my motors as standard practice. I'm also using 470 uF and 0.1 uF capacitors around both sides of my voltage regulator. As yet I haven't tried applying a cap to a servo, and I have a quick question.

Speaker Noise

Greetings fellows,

Still plugging away on my big project. All goes well, except my 8ohm speaker is giving off a trememdous amount of noise while it's on. It works fine, but there is always a high-pitched "white" noise.

In addition, my project uses small servos, and i've noticed a "click" sound come out of the speaker whenever I turn the servo off (low 1). I assume the problems are related.

Is there too much power going to the speaker? Do I need some sort of voltage regulation or supressive diodes or who knows what?