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Speed control of L298 controller

I'm hoping the fcan help me identify what needs to be done to implement speed control of the robot motors. This is the section of the code for speed control. 
The right motor speed can be controlled, however the left motor does not turn at all.
I'm new to Aurduino progamming so I'm sure its a simple problem. My goal is to implement blurtooth control in this code.
I need to implement speed control in the Android app. I've not come accross any Android apps that offers speed control, 
just directional control.

Help with collision avoidance code

I finally got my robot to avoid obstacles! I thank those that help me identify the problem Now I need to vary the speed of the
motors. I've commented the code I wrote to accomplish this. The sketch compiles without errors, however the int motorspeed does not vary 
not vary the motor speed. I'm new to Aurduino programming and sure its a simple problem.

Help with collision avoidance code


I'm hoping someone can help me with is code. The motors on the robot never turn, no matter the distance at which an obstacle is encountered. The ultrasonic sensor, servo and motors have been verified and our functional. I've also ran several other similuar sketches with the same results. The battery is fully charged. Any help is appreciated.

//Since we are using servos and ultrasonic sensors in the robot we will include some libraries written to make their use easier
#include <Servo.h>
#include <NewPing.h>

Help Choosing a 3D Printer

I have been looking at the Ultimaker range, the original Ultimaker is available for about £900 (I am in the UK).

I found a Tech Rader Top 10 3D printers here but the only Ultimaker that was listed was the Ultimaker 2 Go but this only has a small print size and is restricted to PLA only.

How to interface with PC

I'm a beginner at robotics, but I do have a background in programming and some artificial intelligence and I'm planning to build an autonomous robot with an onboard computer. I may be able to use a Rasberry Pi, but I'm leaning towards a more powerful PC running (perhaps) Ubuntu. What would be a pragmatic (hopefully quick and easy) way to interface the PC with the inputs and outputs? Inputs would be ultrasonic sensors and probably either an infra-red camera or (inexpensive) laser scanner. Outputs would just be various motors to control wheels and an arm etc.

Can i change the servo sweep like this (picture attached)?

Hi All,

I want to change the sweep of a servo so it behaves like this (see below picture).  

Does anyone have any clues how i can do this?  Do i just rotate the potentiometer, output gear, and any other gear with the mechanical stop by 90 degrees?  I really hope the potentiometer is not glued on because that is going to make it difficult.

Servo motor power source

For a project I need to make my teacher advised me on using a servo from parallax


According to the datasheet I shouldn't connect it to the Vdd and Vss from the microcontroller.

Would it be ok if I would it on the same power source (being my batteries) but my controller gets 5V from a regulator and my servo would be getting 7.2V directly from the batteries. (could also lower it to 6V)

Android Robt controller app Rocketbot

I am seeking the Rocketbot Android app. It no longer appears to be avaiable. Does anyone have knowledge where I could get this app, or a suitable app. I need a controller app that has speed control, its difficult to find such an app.


Any help is appreciated.





Funding Expensive Robotics Projects

Hi all,

I have this really big idea in mind for a robotics project. I'm not going to release details about what it is yet, but whatever it is, there are two problems that keep it from becoming a reality:

The MeccaNoid Android App. is frustrating to use and buggy

MeccaNoid does- The Hokey Pokey SONG


I did this with the Android App., it was frustrating to use and buggy. It took me about 25 tries to get it close to right, the ending is not correct, but funny. I changed the voice to +30% pitch to sound more like MeccaNoid.

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.