Engineers make a schematic to explain their circuits.

One time I was looking for a non-tourist pub in Japan. I asked someone for help. She said, “I’m sorry, but I do not speak good English. I will bring my friend, and she will draw you a map.” (Exact quote!) The map her friend drew, gave directions to a bar with a “Neon Yellow Sing.” She meant “sign.”

The map was the method we used to communicate with each other, even though we didn’t both speak English. With this crude but useful map, I could find my next drinking place destination.

Schematics are the same as this map. Even if you don’t speak the same language, you can communicate how a circuit works when you make a schematic.

Use one of these five tools, when you need to a document a circuit or when you need to ask for help.

Your challenge, if you chose to accept it, is to determine why EAGLE is showing a ratsnet connection on the far left of the PCB layout. The pads shown with the yellow unrouted line are both GND. They are both surrounded by a ground plane, which is also connected to GND.

If you are anything like me, your copy of EAGLE has an extensive list of libraries. Most of them probably came with the installer, some which you have added. This, of course, leads to the problem of finding the parts you need when drawing your schematic. Here’s how to use the “Search” box to help.

When I teach the Electronics Measurements class at the TechShop in Austin, I take a lot of pride in showing off the Mixed-Signal Oscilloscope.  We have a Rigol DS1102D as well as a standard DSO.  To help illustrate the power of the combined digital and analog channels, I  created a Mixed Signal Oscilloscope Demo Board, based on a counter,  that has an issue that could be turned on or off.  This board is also my first time making use of OSH Park’s PCB service.