I recently discovered iCircuit, a neat little circuit simulator app that works on Mac as well as mobile devices. It’s perfect for simple effects pedal designs.
A common way to prototype simple electronic circuits such as used in guitar effects pedals is to use a breadboard and real components. This is great for audio projects because you get real results that you can actually hear right away.
Breadboarding, however, it has it’s challenges:
The top four breadboarders headaches:
1 – You have to buy all the parts.
2 – Anything complicated quickly turns into a rats nest.
3 – Routing sensitive signal lines is a nightmare.
4 – It’s hard to get high pin density SMD micro controllers onto a breadboard.
Now admittedly the last two may not be an issue for basic effects pedals, but we are seeing more and more complex micro controllers and CPU’s becoming available to the maker community, and it’s only a matter of time before home-brew digital guitar effects come more commonplace.
An alternative to breadboarding is to use a computer based circuit simulation application. The ones most commonly used in professional electronics are based on SPICE. Many companies that develop integrated circuits create their own SPICE based tools, and Linear Devices makes theirs, LTSPICE available for free which is pretty cool.
The problem for Mac users is that although there is a free LTSPICE version for OS X, the user interface is pretty clunky. It lacks a tool bar for the schematic editor which makes editing layouts directly pretty cumbersome and you have to import schematics in from something else which is a whole other business. The Windows interface is much nicer.
So this lead me to search for a simulator for OS X and hence to iCircuit. It’s a neat little app that’s great for students and hobbyists and supports both analog and digital circuits with inbuilt oscilloscope and meter simulations. There are a couple of headline features:
1. OS X, and IOS versions for Mac, iPhone and iPad
2. Real time simulation
The OS X version works fine and has a nice Mac like user interface. I didn’t try the iOS version yet but the screenshots look very nice.
The realtime simulation is quite fun. Most simulators provide simulation results in the form of a series of reports, but iCircuit simulations run as you work, so you can quickly see how changes to components impact your project, and you can monitor signals with the scope and meters as you go.
The library of components in iCircuit is pretty limited, so it’s not going to replace a SPICE type tool for professional simulation, but for learning and testing simple circuits it’s pretty useful and way more fun.
There are links to download iCircuit from the developers website. At time of writing, there are versions for OS X, Windows, iOS, and Android at between $4.99 and $9.99 depending on platform.