Materials searching and requests

Brainstorming about physical/mechnical/practical design problems

  • How to Get What You Want is a wonderful resource full of creative fabrication ideas for sensors and actuators, curated by Mika Satomi and Hannah Perner-Wilson.
  • Five Hundred and Seven Mechanical Movements was an 1868 book by Henry T. Brown featuring 507 drawings of mechanical linkages. The website reproduces these drawings and adds animations to some of them which make their movements easier to understand. The original text (which includes narrative explanation of all of the drawings) is in the public domain and can be browsed or downloaded here on the Internet Archive.

Electronics software

Most useful for drawing schematics

  • CircuitLab is a web-based circuit design-and-testing program, which has some useful features such as automatically drawing traces at right angles between two connection points. It’s also got complex circuit and logic modeling built in. CMU has an institutional membership; go to to sign up for an account using your Andrew account so you can use the full functionality, including exporting images of your schematics, for free. Unfortunately, the software has a relatively thin drawer of parts, and it does not include the Arduino—which means it’s not especially well suited to drawing schematics to turn in for your homework in this course.
  • Fritzing is an open-source electronics documentation program that now costs €8 to download, though it used to be free of charge. It’s a beginner-friendly way to draw schematics, breadboard views of electronics, and even design PCBs to be sent out for professional fabrication.
  • EAGLE is impressively old (initially released in 1988) professional grade software that’s now being given out for free by Autodesk. It is not especially beautiful or user-friendly, but is an industry standard program in electronics. The software is also now built in to Autodesk’s Fusion360, so if you already have a copy of that running, you can select “new electronics design” under the new file menu.

Most useful for simulating behavior

  • Tinkercad Circuits, by Autodesk, is closed-source, free-of-charge software that is aimed at the youth STEM education market. It also happens to be, by a wide margin, the most user-friendly Arduino circuit simulator currently available. The software does not allow you to draw true schematics, instead opting for a very straightforward real-world-imitating visual representation of electronics components. We will make use of it especially at the start of the semester.



  • Adafruit is a great educational electronics company out of New York City. They manufacture and sell their own products (we carry their NeoPixel Ring, for instance) and are a reseller as well. They generally have excellent documentation and tutorials!
  • SparkFun is an education-oriented electronics company out of Boulder, Colorado. They have a broad variety of components and often have good documentation.
  • Pololu is a hobby/educational electronics company out of Las Vegas. They sell lots of parts including a broad selection of motors and other actuators.
  • Mouser and Digi-Key are both enormous electronics supplies houses. They have catalogs of millions of items, and will likelier than not carry any fundamental component you need (such as a specific resistor, transistor, LED, integrated circuit, etc.). A note about availability: we use many pre-assembled PCB boards in our lab, such as the ADXL335 accelerometer—Mouser and Digi-Key won’t likely sell an assembled board like that, but rather just the IC that is the brains of the part.
  • Arrow is another big electronics supply house which (currently) offers free overnight shipping on any order. Daily shipping cutoff is 9 p.m. Eastern.

Mechanical parts

  • McMaster-Carr sells an enormous range of hardware (such as nuts and bolts) and raw materials (sheets of aluminum). They have an excellent search and overnight shipping at low cost. Daily shipping cutoff is 6 p.m. Eastern.
  • Grainger is another hardware giant with a huge range of parts.