Let's Make Robots!


add.pngSubmit Something else Did you make something else? Show us


How to post photo in blog?


Brand new member here.  I'm working on the first blog post, but how do you include a pboto, it says to enter a url?  I tried uploading to tinyurl and using tbe links but they didn't appear.   I also tried uploading the photos from my phone to the My Stuff page but if I select them from there nothing appears in the blog.


Mosfet motor driver?

Dear: LMR

Just to let you know I want to use a two mosfets to control two 9 volt motors. I managed to find this circuit online for controlling a motor with a single mosfet and they say it can move the motor both directions. I looked at the circuit from my knowledge it can only move one direction. InA controls both directions of the motor. Can I please have some help? Thank you.

From: Noah

1 second delay with NRF24L01 servo control


I am building a Project which targets to:

Driving the Car with Steering Wheel connected to PC.

PC connected to Arduino which will transmit the Steering wheel commands to other Arduino via NRF24L01 modul.

On Car Side:

connecting a lazer rangefinder to a liner actuator

I am trying to see if its possible to connect a lazer range finder to a liner actuator maybe  via something like an arduino and be able to preset positions on the actuator that relate to the distance the lazer is reading. I am looking for fresh talent to take on this challenge and claim the prize at the end of the project, that is if it can even be done. Any interested parties please feel free to contact me and I will answer any questions you may have. Thank you.  Leo  Masters               cambodiaman1@yahoo.com

Cutting Acrylic sheet

I've been asked how to cut acrylic with a hot wire cutter - I made my own and there are a few plans for how to do this on instructables etc. This was my take on the idea which I find works OK for me... - see the file attached

getting started with nRF24L01

Hello guys I'm trying to send message from arduino due to arduino duemilanove atmega328 using nRF24L01 

arduino due is the transmitter and the code is


Cliff Sensors

Hi, im looking to incorporate cliff sensors into my robot similar to the ones used on those robotic vaccume cleaners. I am using the picaxe 28 pin project board given in this tutorial http://letsmakerobots.com/node/17. Would i be able to use 4 infared proximity sensors https://www.sparkfun.com/products/12728 to achive this or is there something better i could use.



CAD software


i was asking peeps earlier today (last night? its all blurring together) about the best CAD packages for 3D design and was pointed in the direction of inkscape...a bit of playing around and you tube research and i came to the conclusion its a cool program but a bit more like gimp or corel for my needs.


a little more research and i happened across google sketchup - and my god its amazing -

Botboarduino drivers

Ok guys it's been a while since I've been on I'm glad everything is picking back up.

I recently had to wipe my computer after getting a virus. Which means I lost all my drivers and code and etc. I managed to get arduino up and running but my botboarduino needs drivers to work. I'm kinda freaked out about catching another virus and I can't seem to find the correct drivers for ft232 uart. I tried one place but it keeps asking me for a password to open it. And when I point the device manager it refuses to see the zip file.

Need help with basic electronics

Hi again,

I was hoping someone might help me out with an electronics thing.  I've got a small camera with a button to turn it on etc.  I've soldered 2 wires around the button, so when I touch them together it "presses" the button - this works as expected.

New LMR Slogan!


We've tallied the votes, and the new LMR slogan is LEARN.BUILD.SHARE.

Thank you to everyone that suggested slogans and everyone that voted. A special thanks to OrionBot for proposing the winning slogan! In order to thank you OrionBot, you'll get a small token of our appreciation via e-mail soon. Enjoy!


Construction design help

Im trying to build a machine that would be carried by a drone and drop balls at an interval.  Ive done a lot of research but Im still new to this, Im planning on using arduino nano to control the 2 servos I need to operate the dropper.  My question is, can I power the arduino and the servos with the same 7.4 volt Lipo battery?  It looks like the arduino itself can take the 7.4v with the onboard voltage regulator, but it looks like that it will only output 5v which is not enough to power my serovs (need 6v-7.4v).

Good Motor Controller?

I've been looking for a motor controller that I can use for my Arduino. I've been over multiple stores, but I'm not sure which would work best for an Arduino Uno. I'm also looking for a Triple h bridge or higher so I can control more than 2 DC motors. Range needed is at least 5v- 12v. Anyone have any good suggestions, first time using a controller that doesn't have motor controls built in.

For the tl:dr; version:
*I need a motor controller that fits on an ardunino uno
*Works at least in the 5v min range
*Needs to control 3 or more DC motors if possible

Problems with TowerPro SG90 servos and Pololu Mini Maestro 24

Hi all,

I am in the process of connecting up 18 Tower Pro SG90 servos to a Pololu Mini Maestro 24 controller to complete my build of a Plen 2 (Custom redesigned to fit the above servos and allow space to carry the controller).

I am using an adjustable power supply that has voltages of 3, 4.5, 6, 7.5, 9 and 12vdc.  The label says that the output is 300mA 3.6 VA max.  I am suspicious this could be my problem detailed below.

What questions to ask during an interview

More and more I find myself interviewing new staff for our company, with the remit being - find another you. I am currently overloaded justnow because i am multidicplinary, but i cannot seem to find anyone else who is - they are either, mechanics, programmers, electronic engineers or mechanical engineers. What kind of questions can i ask to dig up the real interviewee? The boss wont let me base my decision to hire on the ' do you own a raspberry pi? Or have you ever wanted to build a lifesize dalek?

Powering SG90 servos with lipo and BEC

Hi there,

I'm building a robot with 15+ SG90 micro servo's.

To power it, I've bought a 2C lipo battery, and a 5/6 volt BEC.

I've hooked up the BEC's 5v (red) to all the servo's red, and the BEC's ground to the servo's ground, as well as some arduino grounds (that control the servo).

The BEC has an on/off switch.  When the BEC is switched to off, and I plug the battery into the BEC, a surge of current flows through to the motors.  They all "twitch" very rapidly, and I've had some wires melt/smoke.

My questions are:

Trouble getting Redbot to turn using encoders

I am trying to turn a redbot precisely (relative) 90° using the encoders but I cannot figure out how to do this using the encoder tutorial. Any thoughts on how to do this?

I think i am getting lost in the serial side of things. Pretty much i want the robot to drive straight turn 90° drive the same disrance back and end up back at the start. 

Wha are the basics of robotics that I've to start learning

Hi, I'm a biginner in robotics, so I don't know what are the basics that I should learn, or start with, so please can you guide.