Politicians like to get elected, mechanics like to fix things, musicians strive for melodic perfection, and engineers, well, they just engineer. I like to sit around studying widgets made of complex PCBs loaded with lots of itty-bitty parts.

There are times when an idea for an article just comes to me. Other times, readers send me their ideas. This month, I couldn’t see the forest through the trees. And, to add insult to injury, I was lost in the forest as well. For a day or two, I pondered what to tell you about this neat collection of resistors, capacitors, ICs, and industrial-strength connectors spread across a couple of high-density PCBs. Project idea after project idea passed through my head. I decided that I really don’t need another water sprinkler controller, and you probably don’t want to read about one either.

So, there I was wandering around the Florida Room trying my best to come up with an interesting application for this gadget named after wild dogs that are famous for singing with the cowboys and howling at the moon. After I cleared my head, it occurred to me that I was walking the wrong dog. I decided to start from square one, and took an inventory of what the product I wanted to tell you about is made of. 

MY COYOTE

First of all, the Z-World Coyote is designed with an Ethernet interface that’s supported by the latest Rabbit 3000 microprocessor. This doodad is as good as any, with Ethernet capability that makes me wag my tail and perk up my ears.

There’s also a lot of brawny I/O in the Coyote’s poundage, including nine filtered and protected digital inputs, eight digital outputs capable of sinking 200 mA at 36 VDC, and seven high-speed unfiltered protected digital inputs. So, I can turn on and off just about anything over an Ethernet link under precise microprocessor control.

A big green coin battery on the Coyote’s I/O board suggests a battery-backed, real-time clock. Not only can I turn stuff on and off, I can do so on a schedule and in bad weather. An assessment of the available analog I/O reveals a single A/D input and a couple of D/A outputs. The A/D module could come in handy when making switching or data output decisions that are based on external voltages. The D/A output could be used in a voltage-control application like setting a machine tool motor’s speed and direction. I could really make some motors sing or generate some weird auxiliary voltages using the two Coyote 9-bit PWM outputs. 

In addition to the Ethernet port, my personal favorite, the Coyote has six serial ports. I should be able to do something with them; after all, serial ports are my life. In the memory corner, there’s a 128-KB bucket of SRAM supported by a 256-KB washtub of flash memory that I can cram code into. Four programmer-accessible on-board LEDs act as debug indicators. You may use them to flash coded status to an end user. 

The final feature that should have tipped me off regarding the application of this embedded system is the 100 mm × 100 mm board, which is perfect for DIN rail mounting. Photo 1 shows my Canis latrans (coyote) sans a leash.