Building gauges and gadgets with Arduinos, Raspberry Pis and Switec stepper motors.

Jan 19, 2012 - 1 minute read - Comments - Switec X25

X12 Quad Driver Chip

Switec X12.017 Quad Driver The X25 data sheet describes the X12 family of driver chips which allow up to 4 Switec motors to be controlled over a 3-wire serial interface. I like the look of these for keeping the I/O count down, and offloading a bunch of processing from the Arduino. However I have been unable to find a supplier for X12 quad driver chips. It seems that they were available until recently from Swatch subsidiary Microcomponents Ltd. at, but after Swatch sold the stepping motor business to Singapore-based Juken Techonology in 2009, that website disappeared.

There appear to be several other manufacturers making clones of this chip. Here’s what I’ve found so far:

NOST also manufacture the BY8291, a 16-pin dual driver .