Let's Make Robots!


motor driver suggestions - 6v 6a stall

I am looking for suggestions on how best to drive my Pololulu motors on my MopBot.  This bot is basically a swiffer mop attached to the bot which it pushes around so it requires more torque than the usual small bot I have done before.  These motors are rated 450 ma @6v with no load and 6 A stall.  I am using 6 NiMH AA batteries in series for about 7.2V - 7.5V although could go higher if needed.

L297 and L298 problems

Hi LMRians!

I do not know how should i chose the amount of resistors needed for the currents sense pin of both L297 and L298! It seems that they control the amount of current flows through the winds of the connected stepper motor. right? but how much resistance they need? Surley, it is related to the stepper motor. how is it related mathematically?

L298 problem

I'm making a robot and I'm using an L298 to drive 2 DC hobby motors (specifically, the tamiya twin gearbox). For some reason, the L298 give out 3.4V on its outputs when applying logic low to the corresponding input. Does anyone know why this is? I am going by the example schematic in the datasheet, using 5V for logic power supply and 9V for motor power supply.

This is modullo, one of my first elaborated robotic platforms. It hasn't got an actual purpose yet, I'm at the stage of adding various sensors and integrating them … Read more
Navigate by commands from android device or computer
Using a
Update #2 10th June, 2011 Added another video showing the robot doing tight pirouettes on a small kitechen scale. Update 10th June, 2011 Added new pictures, which … Read more

CNC Machine V2 with RepRap Controller

I finally finished my Fireball V90 CNC build.  In May, I got the frame, and I planned to use the motors and electronics I purchased for upgrading the Valkyrie-clone CNC.  So I made some NEMA-17 to NEMA-23 adapter plates from CD-R disks, and got it all up and running.  It's running off 12V for now, with 24V planned in the future.


This is my second attempt at a robot, and my first more or less blind since I basically followed the start here tutorial for my first one. My goals here were … Read more

RepRap Stepper Driver v1.2 and Next Gen CNC

In the picture from top-left, clockwise to bottom-left: the terminal block (24V power up to 13A), the 2 X-axis drivers, the Y-axis driver (blue heat sink), and the Z-axis driver (blue heat sink), the Arduino controller (direction x3/enable x3/step x3), and just below the terminal block there is a small 9V regulator board to shift 24V down to 9V for the Arduino.  Everything is mounted on an MDF board, and the board is mounted with baling wire.


Old pic: http://letsmakerobots.com/files/clone_cnc_closeup_1500px.jpg TinHead's Original: http://letsmakerobots.com/node/9006 Vector Drawings: … Read more

HaBot photo

Habot v1.1

Function work now, trying to do funny thing.

1. tank can go forward, backward, turn right and left.

2. Detect the object distance

3. stepper motor can turn to absolute angle.

4. detect distance on every angle of stepper motor and find the shortest distance of every angle.



Help with connecting Arduino clone to L298 based motor driver

I am quite new to the world of robotics, but have years of experience with basic passive components (caps, resistors, etc) so I thought this would be a fun way to start learning more.

 To start myself off, I picked up a handful of arduino clones, mostly seeeduinos.   I built some motor shields and got those programmed, and working successfully with some cheap hobby motors, I've also successfully managed to get some servo's running without a problem as well.

My First BatchPCB, er batch

So I finally got my first home designed PCBs back from BatchPCB.  As a bonus, I got double the parts I ordered.


My L298 Motor shield:


My Q1114 sensor board (for line following/wheel encoders)  The mounting holes will need some rework.


  Update: 13, April, 09 This time I added the Solarbotics L298 Compact Driver Kit, the car is now much more powerfull and it is very cool to drive.   Read more