Let's Make Robots!

circuit

theory vs. soldering

Well...my robot is far from being able to be presented.

In fact I try to build/solder some parts on my own, which seems to be more challenging than expected. Actually I´m soldering a h bridge with its controller based on oddbots h bridge - without the current sensing part - and I just hat to face, that it doesnt work. I guess its not due to oddbots design, but to my soldering skills and or adapting to a simple board design, since I solder though-hole.

I hope I can figure out the problem soon...

question on a h-bridge circuit I found on this page

Hello everyone,

well, I´m pretty new to this community and I hope this post is not too dumb in your eyes. I´m more at home when it comes to computers but as soon as I get into contact with circuits and means to make a computer sense the "real world", I thought about giving it the opportunity to drive around next to other actions. In fact I´m trying my best to deal with microcontrollers and learn by doing.

Yellowbot, the circuit, or I love Fritzing.

While messing with my Arduino I found the circuit diagraming program Fritzing. I really love this program, it makes docummenting breadboard circuits increadibly easy.

You can get the software from their site: fritzing.org

Choosing a transistor

I've used two types of NPN transistors in the projects I've done so far and I've tried to investigate why, but my conclusion just doesn't seem to make sense (actually, I'm not sure if I've reached one...).

For use with an Arduino, I've used a PN2222 transistor:

 

Whereas, for BEAM solar bots, I've used the 2N3904:

 

Project Phoenix (ALAN's new look)

hello everybody! it's been a long time since i have updated ALAN, i've been busy for some events, and still am, but i have manage to fix some bugs.

i still haven't added his arms yet, and the battery died (must be a short, RIP), but i will buy a new one when i have time (and money).

so here are the updates:

CAUTION: what you are about to see can and will make you sick, i warned you about it, so prepair a bucket and a mop!

if you want to comment, don't comment here, comment on this link:

Comparator circuit question

I have been playing around with BEAM robotics and I have found answers to a lot of my questions but this one still persists. Why does there have to be a pull-up resistor? Can`t I interpret the signal without it? My first guess is that if Vin is smaller than Vref then V+ at the top of the pull-up circuit will be grounded through the op-amp so that Vo is grounded as well. In the other case, electricity flows through Vo and I can use the signal to activate a transistor.

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.

Capacitors

Hi y'all, just joined LMR, fantastic site, lovin' it already . . .

 

I am a bit of a beginner to robotics, I mean I can program and all that, and make these things, but I know not how or why they work.

One thing I have been wondering is about capacitors:

When designing a circuit, how does one know where to place capacitors, or why to have them, or how they function in that position?

With this circuit in particular (from here: http://letsmakerobots.com/node/2074), why the caps?

those two in the top-right, why do they both need to be there?

Pulsing circuit

Hi everybody. I have an idea for some wierd stuff (I don't want to say what it is untill it works), but I don't know how to make it and I don't know how to google it.

I need a circuit that uses one DC power source, and a capacitator, and it can't have any switches, it has to work all the time the power is conected. It needs to charge the capacitator and when it's full send all the electricity it to the "Parts"/electronics. But "Parts"/electronics shouldnt get any power while capacitator is charging.

My first robot..........

So I've decided to build my first robot which not the LMR "start here" one (that one is going to be my second one) and im using this circuit- http://costaricabeam.solarbotics.net/Circuits/Vores/555%20Photovore.png . I've tried about 10 different designs for the body but its just not working. When i cover the left photocell with my hand and the other one is exposed to light the speed of the motors is the same and same with the right photocell. has anyone tried the circuit? did it work?

Dual Y-Bridge (was One and a Half H-Bridge)

I had an idea tonight that is either inspired... or stupid. Please help me determine which. ; j

I was thinking about using one of my new Picaxe-08 processors for a project. They only have 5 I/O ports, three of which can be either an input or an output. However, for my project, I wanted to be able to control two motors and two sensors. Since traditional dual H-Bridge designs would require four processor outputs to control two motors with forward and reverse, that would leave only one I/O port left. Boo hoo.

Setting up a QRB1134?

Does anyone know how to set up one of these things:

qrb.jpg

I can't seem to get it working.

Someone made a quick "tutorial" on LMR but I just don't get it.

I found a diagram here that just doesn't make sense. The wire colors are all messed up.

Then I found this:

My 1st non-breadboard circuit :)

I know..a lot of you good folks could solder before you could walk and probably sleep with a soldering iron under your pillow (hope you remember to turn it off :), so here is this guy in his 30s bragging about his first circuit. Pathetic.

However soldering is a major challenge to me and actually the main reason I didn't get started with robotics years ago. It's just not easy for my unsteady hands. So I'm very happy to declare that I just finished my 1st working non-breadboard circuit. It's a motor+servo shield for my Arduino.

Other electronics (not necessarily robotic)

A place for the discussion TofuRobot brought up regarding other electronic projects. Instead of being lost to the shoutbox nether regions,here's a screenshot of the beginning.

shoutbox-electronics-section.png

Personally, I think tip/walkthrough would be the right place for stuff that can also apply to robotics. Non-robotics (like the carduino example) would go in a blog.

 

Photocell to motor circuit not working. :(

Ok, to make sure I would not mess up I got a little help reading the circuit from Instructables. After following this word for word, I found that my circuit simply did not work, and when I touched the transistor it was extremely hot.

 Photocell_Motor.jpg

Here is what I put together following the instructions:

 3608357805_52820f6085.jpg?v=0

[Honestly, that's the best photo I got.]

 

NEED HELP! with my motor controller


Hello guys. I'm creating a RF controlled 2.5kg sumo bot. I'm a mechanical engg. student and so don't have much knowledge in electronics.

Basically I need to create a 10Amp motor driver for driving 2 12V dc motors,10A each using relays.
Buttons on remote control:

      1
2           3
      4

1-Move Forward
2-Rotate Anticlockwise
3-Rotate Clockwise
4-Reverse


I'm planning to use these schematics for radio controlling

Fat Man and Circuit Girl

Nerd TV done right. Two people in their respective "labs" video chatting live for all to watch. Recorded shows on Vimeo.


254711512_200.jpg

Impresive geek biographies for the both of them.

click

breadUino

This came up with the need of having the arduino permanently installed on the robots, I´m tired of having to remove the arduino from one bot to the other, and then rewire everything, and then reupload the code everytime I have a new idea, or everytime I want to show the bot to someone.
I followed the ITP Physical Computing tutorial, and it works like a charm, no I want to try to upload code with the FTDI cable, and If I have success on this I can start making my custom Arduino boards. :D

Line follower "GOOFY"

This is my very first line following robot that is built around ATMEGA8. Construction and circuit are quite simple. Such a name- GOOFY is given because robot movements are somewhat clumsy. But hey! Its still working and doing his job very well! :)

1.jpg

There is two geared DC motors that are controlled using PWM. Tyres are the ones that are used in RC cars. Besides-these have a nifty looking. 

NPN vs PNP, a fundamental or just a mental difference

Like many here, I were in need of a bit of amplification of a weak signal. This signal had "low impedance", I suppose. The supplied circuit diagram shows two different ways of meeting my need.

The left circuit uses a NPN transistor. The right hand circuit uses a PNP transistor. I chose the one with PNP. Quite "arbitrarily". The BP103B is also known as FA300.

Suggestions for a Book on Circuit Design

I have a fairly strong background in code development, but I would like to build a stronger knowledge in curcuit design. I can read a datasheet and learn how to hook up a certain component, but when it comes to using a specific component for a use other than it is designed for I lack the knowledge to know when to use a capacitor, flyback diodes, etc.

Schematic design software

I'm not positive this is the right place to post this.  Admins please move it if I'm asking in the wrong place.

A Circuit I cannot understand

I have a circuit digram but i cannot understand it. can anyone help me explain?

 

Pjnai123