I’ve been doing some research on schematic and PCB CAD software to pick out which package would be the best to use with my students here at BCIT. I’d like to share my observations and request some feedback or suggestions from the CD community which, I am sure, has opinions on such matters. I do, however, have some specific criteria in mind.
**The Students:**Are adults, studying to become high school technology education teachers. Many have previous education or experience in trades or technologies, but few have electronics experience and, as mechanically minded people find the theoretical and troubleshooting aspects of electronics a new and challenging experience. They are keen to learn more about electronics and teach it to their future students, so I want to keep it as fun and painless as possible.
**The Software:**Should be free, so that they can learn here and take the software with them in to any classroom or shop in the province.
Should have an easy-to-use, easy-to-learn interface.
Should produce printouts of single sided circuit boards suitable for production using a toner transfer or photographic process.
Should link the schematic diagram to the circuit board.
Does not need auto-placing or auto-routing, but it’s nice if it is there.
Does not need to produce multi-sided, large, or complex boards. This is for teaching high school projects, not commercial production or research.
**The parts libraries:**Basic components such as through-hole resistors, diodes, LEDs and transistors should be easy to find.
A few common IC’s including PIC microcontrollers should be available.
Right now the “best” package I have found based on these criteria seems to be Diptrace Lite. It has common components fairly easily accessible in its library, is reasonably decent at creating schematics and links the schematic to the PCB. The autoplace and autoroute functions can be set to run on just one side of the board and seem to do a decent job. I’ve only played with it for a while, but I get the feeling that its learn curve is “less steep” than some of the other packages.
Some of the other software packages I have looked at include:
Eagle: I’ve used this quite a bit in the past, including with high school students. It doesn’t have the easiest UI to learn, and sometimes it is difficult to find basic parts. For hard core electronics junkies, that isn’t a big deal, and it is fairly powerful and widely used, but unless I were to custom build a library of common parts, it would be frustrating for a beginning student to find what they need. And even then it would require students to do a custom install of the “easy” library. It has good support for autorouting, however, and is a fairly standard package it seems.
PCB123: This has a really nice user interface, links its parts library to digikey’s database to make ordering easy and seems to work quite nicely. The knock against it is that the parts library is SO extensive that it also makes it hard to find a simple 1/4 watt through-hole resistor or 5mm LED. Sure I can find them… but I have to look… that will be a bit frustrating for a student who doesn’t need 1,000+ different types of resistor to design their board. The other catch is that the licensing agreement limits you to only using data generated from their software to produce boards with their service bureau. Technically, printing and producing our own boards may be a violation of the license agreement. Yeah, I know they’d never know, but I do try to respect IP rights. But it is probably my number two pick of the full-featured packages otherwise.
ExpressPCB: I’ve actually used this a fair bit, but where other packages are too “high end”, this one seems to lack some of the functionality that makes using them rally easy. My main beef with it is that while you can link a schematic to a board, you need to manually populate the board with components and name the components identically to the schematic. Even then it doesn’t do autorouting, which isn’t that big of a deal. The parts libraries aren’t bad for a beginner, though, and ExpressSCH, the schematic software makes it quick and easy to knock off a simple diagram.
And the outlier… the up and comer… the one that is really really cool, but not quite ready to do everything that I need is:
Fritzing: I love the breadboard CAD aspect of fritzing almost as much as I hate the fact that it takes me 15 mintues with graphics software to “bend” the leads of the components so I can fit them on the virtual breadboard the way I’d fit them on a “real” breadboard. Still, it is very cool that it links a breadboard, schematic diagram, AND PCB together. The parts library is simple, but sufficient for most high school projects, particularly if you can be a bit creative in what you select, or if you use arduinos, which are really well supported. This is still a beta project, however, and occasionally crashes on me, but shows enough potential that I am excited about it despite the fact that it is still under development.
There are other packages out there… http://www.freepcb.com/ is one, but I don’t have time to play with them all. Does anyone have any suggestions as to a package that I should be considering in more detail?
P.S. Yeah, I know… Altium is free to FRC teams. As great as it is, however, it is most definitely not free if you aren’t an FRC team and, like some of the packages above, might be more complex than needed for a high school setting.
P.P.S. If you should happen to know anyone who writes this software… why not suggest they add a “beginner mode” button that limits the libraries and simplifies the options so that it is easy for beginners to sit down and generate their first board. Once they are hooked on the software, they can switch to intermediate and pro mode, taking advantage of the features as their skills increase, but sticking with the package they learned on.