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Sourcing Electrical Components

In general we want to buy electrical components and modules from sources that:
  1. Ship to MIT quickly
  2. Document their products well – at a minimum that means supplying datasheets, ideally might include CAD models, tutorials, example circuits, etc.
  3. Try to keep counterfeit products out of their inventory
The list of suppliers below notably does not include Amazon. That’s because Amazon fails completely at points (2) and (3). They have a huge inventory of poorly-documented or un-documented parts and relying on them for prototyping supplies is typically a setup for a headache later. Amazon-sourced parts are also sometimes non-repeatable, where a second order results in different parts arriving. Whenever possible, don’t buy electronic components or modules from Amazon. That disclaimer aside, below are some options for parts, modules, and printed circuit boards. Online Parts and Modules: Digi-Key Electronics (www.digikey.com) – has millions of individual part numbers in stock and will typically ship same-day for any order placed by 8pm Boston time. The selection can be overwhelming; they have a very robust filtering system on their website. When you have selected all the parameters you care about and are still left with 10,000 options, sometimes you can find a good solution by sorting by “parts on hand.” Typically, if Digikey has lots of it in stock, it’s because that’s the one everyone uses. Other options for components are Mouser (www.mouser.com) and Newark (www.newark.com). Adafruit Industries (www.adafruit.com) – the undisputed world-champion tutorial author, and supplier of (mostly) pre-built modules. Founded by MIT alum Limor Fried building off amazing tutorials she made as a grad student here. Because they are located in NYC, UPS Ground orders typically arrive next-day. Orders received by 11am Boston time on weekdays usually ship same-day. Sparkfun Electronics (www.sparkfun.com) – very similar to Adafruit with a different selection of modules and less-spectacular tutorials, though they are still very good. Sparkfun’s initial claim to fame was in solving the problem in which Digikey overwhelms you with options, and they still carry a large assortment of “normal” components. Sparkfun also hosts a huge assortment of general EE tutorials (e.g. their series of PCB design tutorials is fabulous). Located in Colorado and can ship same-day. Pololu Robotics (www.pololu.com) – supplier of lots of useful mechatronics components including motors, motor drivers, power supplies, robot chassis, wheels, etc. Founded by three MIT alums who originally built modules to support the 6.270 competition. Typically ships same-day for orders before around noon Boston time but it’s not guaranteed. In-person Shopping: You-Do-It Electronics (www.youdoitelectronics.com) – a local store with an entire floor dedicated to electronics components. If you have ever heard legends about Radio Shack (legends that became fiction ca 1982), this is the last store in MA that provides similar service. They are in Needham, about 25 minutes driving from MIT on a good day, and are open 9am-9pm to serve your emergency electronics needs. Historically their sales staff can be difficult to talk to, unfortunately/especially for folks who do not fit their antique biases about what an engineer “should” look like, but if you already know what you need their inventory can extremely useful. Micro Center (www.microcenter.com) – they have a poorly-organized but surprisingly well-stocked DIY section that you can more-or-less browse on their website. They are at the corner of Magazine St and Memorial Drive, putting them in walking/biking distance from the Pappalardo Lab. Printed Circuit Boards: Advanced Circuits (www.4pcb.com) and Sunstone Circuits (www.sunstone.com) – domestic PCB fabricators. Capable of extremely quick turnaround times (on the order of 1-2 days), at a very high price (typically above $1000 for their fastest turnaround times). Gold Phoenix PCB (www.goldphoenixpcb.com) – PCB fabricator based in China. Can turn around PCBs very quickly, especially considering the difference in time zone: An order placed mid-day Boston time can be approved for fabrication later that day and the order completed and shipped by the next morning as an “8-hour” turnaround time (the entire workday in China happened while you were sleeping), with a total cost in the low hundreds of dollars. Because they ship from China, there is typically a 3-day delay at outgoing customs followed by a 1-2 day ship time so overall turnaround is around 5-8 days. Gold Phoenix fabricated all the PCBs for Adafruit and Sparkfun for a long time and is generally easy to work with. They have a front office in Canada that handles engineering questions for English-speaking customers. JLCPCB (www.jlcpcb.com) – another Chinese PCB fabricator. Very low cost (individual PCBs at single dollars per board, plus normal shipping charges) but longer turnaround times, typically 7-10 days to receive. Possibly not usable on the 2.009 timeline but very good to know about. Also has (cheap!) assembly services and will load parts they have in stock into pick & place machines to assemble very small SMD designs. JLCPCB has many factories across China and has therefore been robust vs. rolling Covid shutdowns the last few years. Another option at this price/performance level is Seeed Studio (https://www.seeedstudio.com/fusion_pcb.html) – but they are exclusively in Shenzhen and have been shut down by Covid a few times.