In SX Microcontrollers, SX/B Compiler and SX-Key Tool, JonnyMac wrote:

Go ahead, hook it up.  Your next post will be, "Why did my SX blow up?"  Trust me on this, I've done enough damage to micros to know what works and what doesn't.  [u]Never[/u] connect any kind of inductive device (anything with a coil) directly to a microcontroller; at the very least use a transistor buffer.

Here's the deal: That relay -- which will likely break your SX IO pin -- costs $3; if you put buffering in place (as you should) you're in it for about $3.50 for one channel of on or off control.  An L293D costs $4 from Mouser.  But... the L293D won't hurt your SX and will give you four channels of on/off or even PWM (proportional) control.  You can combine two channels with PWM programming to give your motor speed and direction control, something you'll never get from a single relay.  See the attached program for an example.

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