Four EasyDrivers on one board, with shift register inputs.
Description: We needed to have
an easy way to chain many EasyDriver
boards together. So I came up with the EDQ, which has four EasyDriver
circuits plus shift registers on one board. This allows for a single UBW board to control many stepper
motors (64 stepper motors at 5KHz step rate has been tested so far).
There are two 8-bit shift registers on each board. All of the boards
can be daisy chained by connecting their IN and OUT connectors. (Each
IN and OUT connector has Data, Clock, Latch and Ground connections -
top to bottom.) There is a 5V regulator on the board. The input voltage
is between about 9V and 30V. The driver chips are Allegro
3967 chips, and they are for bi-polar (4, 6 or 8 wire) stepper
motors. There is a current adjustment pot that lets you set the max
current per motor phase to any value between about 150 and 750 mA. (All
four drivers share the same current limit.) These are microstepping
These boards are not commercially available at this time. However, all
of the design files are located below if you wish to make your own.
This version is EDQ v0.8. In the next couple of months (Q1 '08) I will
be updating the design to EDQ v1.0 and will include several
enhancements to the board.
Zip file of Excel BOM, Eagle
schematic and Eagle board layout file
Board Layout (PNG)
Questions? E-mail me at