Let's Make Robots!


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?

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.


Stepper Driver V3 (draft)

Hi all,

I've been working on the driver for the next CNC, V3.

This one should be able to drive bigger motors up to about 2.5 Amps per coil, while providing current limiting.

It's features shold be the following:

- wave, full and halfstepping selectable in software

- I2C and step/dir/enable interface available on board

- home sensors connectors

Below is an iamge of the PCB I layed out:







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.