Linux Stepper Motor Device Driver

This is 3 axis stepper motor driver which can be compiled as a loadable kernel module or as a usermode program. The hardware required is just 4 high gain power transistors and 4 resistors per stepper motor; up to 3 stepper motors may be connected to a single PC parallel port. Step speed may be up to 100pps using the internal jiffie clock. Higher speeds are possible by connecting an external oscillator to the Ack pin on the parallel port.

Currenlty, multiaxis moves will only be linear if the move angle is a multiple of 45 degrees. I need to write a multiaxis implementation of the Bresenham line drawing algorithm.

The software can be donwloaded from stepper.tar.gz under the terms of This License. The schematic is availble in Xfig format, schematic.fig, as a postscript file, schematic.ps, a PDF file, schematic.pdf, and as a bitmap image, schematic.png.

HPGL

Compilation problems

Kernel 2.0

Compiles fine. You need to remove the definition for KERNEL2_2 in the makefile, however.

Kernel 2.2

There are some significant incompatibilities between the 2.0.x and 2.2.x kernels where device drivers are concerned. I have a modified version that compiles cleanly but it hasn't been tested yet. The download link now points to the updated version but I do not have reports of whether or not it works.

Kernel 2.4

Kernel version 2.4 introduces more incompatibilities in the device driver API. A large number of warnings are produced under 2.4. I do not know if the driver works or not. I would say not. It is being ported (see below)

stepper.c:656: warning: initialization from incompatible pointer type
stepper.c:657: warning: initialization from incompatible pointer type
stepper.c:658: warning: initialization from incompatible pointer type
stepper.c:661: warning: initialization from incompatible pointer type
stepper.c:663: warning: initialization from incompatible pointer type
stepper.c:667: warning: initialization from incompatible pointer type
stepper.c:683: warning: initialization makes integer from pointer without a cast
stepper.c: In function `bottom_half':
stepper.c:696: warning: passing arg 1 of `__wake_up' from incompatible pointer type
stepper.c:720: warning: passing arg 1 of `__wake_up' from incompatible pointer type
stepper.c: In function `cleanup_module':
stepper.c:806: warning: passing arg 1 of `__wake_up' from incompatible pointer type
stepper.c:808: warning: passing arg 1 of `__wake_up' from incompatible pointer type
stepper.c:853: warning: passing arg 1 of `sleep_on' from incompatible pointer type

Newer 2.4 kernels such as that included in Redhat 8.0 cause even more problems. As I am porting this driver, I am making some notes at a page entitled Porting old device drivers to linux kernel 2.4

Errata

Note that the names of the parameters are backwards on verbose_outb() in some versions even though the values are given in the correct order when the function is used.

Related Pages (My content)

• My Linux Page
• Software packages I have released
• My Home Page

Links (other people's content)

• Luberth Dijkman has a page on his homebrew XY plotter. This page has a number of links to related pages as well, including various CNC stuff.
• Mel Bartels has a page on his stepper motor controlled Dobsonian Telescope, with links to similar pages.
• Linux Kernel Module Programmer Guide
• Linux Kernel Hackers' Guide