A space for folks to learn and explore wearable electronics together.

Boards/Microcontrollers Designed for Wearables

There are a variety of different boards available to use to control your wearable electronic projects. They vary quite a bit in price and features. Many of the options are listed here along with info on their technical specs. However this list does miss a few options, hence my creating the list below. All prices are in USD and are current as of July, 2019. Unless otherwise noted, prices are for the board by itself; many boards are also available in a kit that may be a better option if you're starting from scratch.

Circuit Playground Classic: The slightly older version of the Circuit Playground Express. It works with Arduino and Code.org. At $20, it's $5 cheaper and has slightly reduced capabilities and hardware compared to the newer version.
Circuit Playground Express: This is the newest offering from Adafruit, developed specifically for people who are just getting into coding and electronics. You can program using a visual, block-based language, JavaScript, CircuitPython, or Arduino (which is more or less C). It is a bit buggy to use with the Arduino IDE on Linux. The board has 10 built in LEDs and a ton of sensors. You can do quite a bit with it, but it also comes with a more hefty pricetag than many other options. You probably don't want to permanently sew in a $25 board to every little wearable project you make.
Flora v3: The latest version of the Flora costs $15 and can be used with Arduino. It's larger than the Gemma and has more pins.
Gemma M0: This is the latest version of the Gemma board; older versions seem to have been deprecated and may not even be available any more. It's $10, about the size of a quarter, and can be used with Arduino or CircuitPython. This is a great option for very small projects. It doesn't have many connectors, however, due to the small size.
Love to Code Chibi Chip: This isn't technically a board meant for wearables, but its small size and beginner-friendly design fits in with the other boards on this list. It can be programmed with MakeCode (the same block-based language or JavaScript system that can be used with the Circuit Playground Express) or an Arduino variant. Coming in at $30 by itself, this is one of the more expensive options.
Micro:bit: This board has a similar target market as the Circuit Playground Express, in that it's meant for beginners to easily get started. It was designed by the BBC and includes Bluetooth (an unusual feature) and some sensors. It can be programmed using MakeCode's blocks or JavaScript, Python, or C. For $15 with Bluetooth, it's a great price.
TinyLily: This $10 board was inspired by the LilyPad line, but is made by TinyCircuits. It's smaller than a dime, yet contains a standard Atmega 328 processor, the same one that's used in the full sized LilyPad, Arduino Uno, etc. This board is also programmed via an FTDI connection; TinyCircuits recommends this adapter, which also costs $10. With as many pins as are available on such a small board, I wondered if it might be difficult to sew, but according to this review it is not. The review also recommends against using this in your very first project, due to the awkwardness of working with such a small sized board, but they do recommend it for more experienced makers.
Feather, ItsyBitsy, Teensy, Trinket: These are all very small boards available from Adafruit in a variety of different models that are sometimes referenced in wearable electronics projects due to their small size. They come at different price points with different features, but none of them are specifically designed with wearables in mind. This means they will be difficult (or impossible?) to sew, as the pads weren't made with sewing in mind. If you need something sewable, consider looking for a similar sewable board. E.g. the Gemma is very similar in functionality to the Trinket.

Then there's the LilyPad line. Designed by Leah Buechley and sold by SparkFun, this line has really expanded, so it can be a bit confusing figuring out which version to use. There are so many options I felt it deserved a section all to itself. There's a lot of info on the larger models on the SparkFun website here and here. But finding info on the Mini, Tiny, and Twinkle requires more digging.

LilyMini: This is the only board which is not available by itself. It comes in a small kit for $15. This board is pre-programmed to work with the other hardware in the kit, but it can be reprogrammed via USB using Arduino. Considering the other hardware it comes with and the fact that it can be reprogrammed via USB, this is one of the better priced options.
LilyPad Arduino 328: Like many of the LilyPad Arduino options, this board will require a bit of extra hardware (an FTDI breakout board) to reprogram, as it does not have a USB connector. It's a standard Arduino with the most pins of any LilyPad board, and costs $16.
LilyPad Arduino Simple: The board has the same chip as the regular LilyPad Arduino, but fewer pins with more space so it's easier to sew. It costs $22 and also requires an FTDI breakout board to program it.
LilyPad Arduino SimpleSnap: This $30 board is very similar to the LilyPad Arduino Simple, but it includes a built-in rechargeable battery and snaps so it's easily detachable for laundering or for switching in and out of different wearables projects.
LilyPad Arduino USB: This Arduino board costs $25 and includes a USB port; not all LilyPads have this feature. It has fewer pins than the standard LilyPad Arduino listed above.
LilyPad MP3: Coming in at $50, this is the most expensive board on the list. However it comes with "an Arduino-compatible microcontroller, MP3 (and many other formats) audio decoder chip, micro-SD card socket, and a stereo audio amplifier". Add speakers, a microSD card with audio files, and power, and you can produce wearable sound.
LilyPad USB Plus: For $25, the same price as the regular LilyPad Arduino USB, this board includes additional pins and some built-in LEDs. The additional pins do mean there's a bit less room for sewing, however.
LilyTiny: At only $5, this is one of the cheapest boards. It comes pre-programmed with 4 different LED patterns. It can be reprogrammed using ICSP programming connectors, but it may be a bit more complicated and won't have as much computing power as other options. If you just want to add some lights to a small project without having to program or figure stuff out or want something small and cheap, this is a great option.
LilyTwinkle: This is pretty much the same board at the same price point with the same features as the LilyTiny. The only difference is the programming; it will make your LEDs "twinkle-fade".