Next, let’s talk about the process that it takes to complete a schematic for a PCB. Selecting and placing your symbols is just one piece to the puzzle. To give you an idea of what it takes to consider a schematic fully complete, here are all the steps:
Let’s start working with schematic symbols!
We’re going to assume that this is your first time working with Autodesk EAGLE. Download EAGLE for free if you do not have it already. Every project is organized into a project folder, with schematics, PCB layouts, and other files all nestled together in one location. This makes it easy to keep things organized. Let’s create your first project and add a brand new schematic with these steps:
Now we have our project folder set up with our first schematic. If you go back to your Control Panel you’ll be able to see all of your project files organized together as shown below:
Our first project folder and schematic highlighted in orange. There’s also a ton of example projects that are included in Autodesk EAGLE for free.
Next, you’ll need to activate all of the libraries that come with EAGLE, and there’s a ton of them! This is one of the remarkable benefits of using EAGLE, as most of the parts you need for your design have already been created by someone else, so you don’t have to spend time making them yourself.
To begin, select the Add icon on the left-hand side of your EAGLE schematic. This will open the ADD Dialog, notice that it is blank.
None of the libraries are showing up that come with Autodesk EAGLE. The solution – they need to be activated first.
By default, when you open EAGLE for the first time none of the default libraries will be activated. So let’s go back to your Control Panel and turn them all on with these steps:
As you can see in the image below, all of the part libraries in our Libraries folder have a green dot next to them. This means that they’re activated and ready for use in our schematic.
The green dots indicate that a library is active and ready for use.
You might have noticed that there are other sub-folders within the main Libraries folder from elektro, element14, etc. These sub-folders didn’t get activated from the steps you did above since the libraries are nested within another folder. But no worries, if you want to activate these libraries just repeat the steps above for each individual folder.
You’ve got your libraries activated now, let’s start searching for and placing your symbols.
Now that your libraries are activated let’s head back into your schematic document and select the Add icon on the left-hand side of your interface. Your ADD Dialog should now look similar to ours:
This is how your Add Dialog should look when your parts libraries are activated.
Let’s find our first part, a timer, with these steps:
Here’s an NE555 timer, notice how every part includes a symbol, footprint, description, and set of attributes.
You just placed your first schematic symbol. Easy enough, right? You can repeat the process above to add all of the parts you need for your schematic. There are a few more parts to add, so head back into the ADD panel and search for the following parts:
If you were following along, then your schematic sheet should have the parts shown below (where they are placed doesn’t matter, right now):
All the schematic symbols you should have so far, we’ve got (4) resistors, (2) LEDs, (1) capacitor, (1) connector, and (3) bipolar timers.
Alright, now that you have all of your parts placed, it’s time to learn how to delete all of those extra timers you added earlier. Then we’ll get your parts facing the right direction with some rotation options, and then we can move every symbol to its proper location!
You have three timers sitting on your schematic sheet, but you only need one. Let’s learn how to delete those extra ones with these steps:
We’re now down 2 timers, leaving us only the essential parts we need for this circuit.
Now that you have all of those unnecessary parts deleted, let’s get everything facing the right direct direction with these steps:
All of your other parts should already be in their correct rotation, but if not, make sure everything matches up with our schematic below:
Now that all of our parts are in the correct orientation we can be moved to where they need to be.
Now, let’s get everything moved into place on your schematic. This part is important as your symbols need to be placed in the way they will be wired on your completed schematic. Follow these steps:
This process is pretty straightforward. Go ahead and move all of your parts around to make it match our schematic below:
Our schematic with all the symbols in their place, ready for wiring with nets.
There’s one handy alternative that we’d like to point out about the EAGLE interface before we send you on your way. In the steps above, you relied on the set of icons on the left-hand side of your interface to perform all of your actions. However, this isn’t the only way to get things done; there’s also the right-click Context Menu, check it out: