Let's Make Robots!

3D Printer - What To Look For?

So I've been doing a bit of looking around, as a 3D printer might be on the cards for purchase soon.

To save myself a many hundred dollar mistake... can anyone recommend what to look for in a printer? Kit construction is fine, but I'm also seeing some $600 - $1000 dollar ones on eBay that look pretty good for a first time printer.

Main applications would be small custom parts for robotics.

Thanks for any opinions.

More code

What I am trying to do with this code is measure air temp and humidity inside a cooler and outside the building, if the cooler calls for cooling say its over 35F, and the outside air is less than 30F and humidity outside is under 65% I want to open and ehaust damper with an end switch, the end switch will close when damper opens, then turn on a fan that will blow that cold air into cooler, also would like to show values on an lcd for a bit of wow factor.




Expressions used with encoders


While I am reading and collecting information about rotary encoders , I faced some troubles about the meaning of some expressions concerned with encoder ,which make me to be confused and stray,  these expressions or words are :

Need help

For some reason gedit just stoped working on my BBB and is giving me the following error;

(gedit : 1072): Gtk-WARNING **: cannot open display

this occurs whether I'm ssl'd in or windowed.

I did an echo $DISPLAY and the value was blank.

So my question is what is this value supposed to be?

I changed it to :1 no luck, :0.0 and couldn't ssl in at all.


Mike the newbie

Yet another possible robot microcontroller...

Hello again!

Take a look at: http://geoffg.net/ 

Then: http://www.circuitgizmos.com/products/cgmmstick1/cgmmstick1.shtml   (I mention the "stick" because of it's size and format.)

These PIC-32 based modules can be used to make entire little 'old style' microcomputers or..... the stick looks GREAT for making a very nice robot controller.

Translation the shaft encoder data

Hi All ,

Have a nice day

Looking to build follow along golf caddy

I'm thinking about building as a winter project a motorized golf push cart. I know that I can just buy them but I can probably build it cheaper and it would be more fun. But I am completely new to this kind of stuff, electronics, I do have some experience in building r/c helicopters, and I am a software engineer. Here is what I would like the cart to do:

Arduino mega issue

Hi everyone, I'm new to this web site and also to robotics so please bare with me, I have a arduino mega 2560 and a mega sensor shield version 2. When I installed the sensor shield onto the arduino mega board the feet where the power selector has been soldered touched the outer casing on the USB connector and cased a short on the board which in turn burnt out the little component ( I'm guessing resistor) next to the USB connector. I have fixed the cause of the problem but would like to know if I can still use the arduino mega with this component issue. Thanks

Learning to use WiFly RN-XV module, any advice?

Recently I have started trying to add WiFi to my robots. The WiFly modules seem like a good choice. Reasonably priced and they fit in an XBee socket so that I can easily swap the hardware between Xbee and WiFly. For this reason I added an Xbee / WiFly socket on the ComMotion shield. Unfortunately I know nothing about networking so I have a steep learning curve ahead.

adding a second dht22

I am using a dfrobot lcd, http://tinyurl.com/kfgbkf9 , and a dht22 temp humidity sensor, http://www.adafruit.com/products/385 , I want to add a second sensor, inside, outside or upstairs, downstairs kinda thing, could I get some clues, I think I just don't get how to name the second sensor, would like to add it after the delay in the loop. Google was not a ton of help?



How to Make a Robot

I am totally new to this world and want to make my first robot Using pic or microcontroller.

I want to make with the parts i have.

Pic12f675,16f877,At89c51,At89c2051,LM339,ultrasonic rangefinding,Lcd,Breadboard ,motors with wheels and many more.

Can any One help me to make my first robo.

Cricket Chirps

Without the shoutbox it seems oddly quiet and lonely. How did we ever have LMR without it?  :-)

"Hello?......"   (echo's down the hallway)


quadcopter board for balancing robot - motor control assistance/ideas needed

I'm planning on using the Micro MWC Flight Control Board DSM2 ESC's X4 Brushed Integrated

Any propellor you want, as long as it's black

Today, on the IRC channel, 6677 posted this link:


where Parallax has open-sourced the Verilog code for their propellor chip.  This could be very interesting.

SRF04 vs. SRF05

I used the SRF05 on a previous robot I built a while back and it was pretty impressive. It was also a little expensive. I just got a deal on a box of SRF04's and got them but I can't really find the main difference between the two models.

Can someone illuminate me?

New to the site

Hi everyone I'm new to this site and would like to say hi it looks a very good site and lots of interesting stuff to do I am very new to electronics and would really like to learn about it and would like to know if any one knows of any good start up projects or information to learn the basics of electronics to progress me further on Thanks

sensing water flow in a pipe


I remember my dad yelling at my sister and I since we took long showers.  My sister had the hot water turned off more than once on her although I never did.

One motor is faster than the other?

Hi makers

Im trying to make my remote controlled robot working. Im using an Arduino UNO with the official motor shield R3. The controller is at this point a simple breadboard with 4 buttons on. The wireless communication is handled by RF links. Im using the Tamiya Twin Gear motors with the following DC motors. Im using the 203:1 gear ratio. Im powering both the shield and the Arduino using two seperated 9v batterys.