Adafruit's Trinket

Looks like it's a software implementation [1].

[1] https://github.com/adafruit/Adafruit-Trinket-Gemma-Bootloade...

My experience with the launchpad has been mixed. The chips are definitely aimed at the low power, low requirements side of things; I had a project where the MSP430g2231's inability to clock from an external high-frequency crystal was a dealbreaker. There's also a wider breadth of hobbyist software targeting the AVR.

If you're a hobbyist, it's definitely not worth saving a few bucks if you're only making a few of them and you account for the value of your time. YMMV.

I rather like the new board but since we're talking low-cost alternatives one thing to consider is buying Arduino-compatible boards directly from China.

My personal experience with boards roughly the size of the Trinket has been as follows: I have purchased a Pro Micro [1] compatible with an ATmega32U4 chip and an on-board MicroUSB port from a Chinese seller on eBay for under $9 as well as two no-name Arduino Pro Mini variants with ATmega328 chips from two different eBay sellers for around $4 each, all fully working. At their price point the latter can compete with ATtiny85 chips directly despite being noticeably more powerful and more convenient to use in many cases. I can't say much about the long-term reliability of those boards (my guess is that if you buy enough of them you'll notice that on average it isn't that great compared to that of boards with officially sourced MCUs) but the ones I got for myself and acquaintances (different models, six total) work as specified for now. The oldest one is over a year old and has been used in several different projects including one that ran continuously for 160+ hours.

[1] An Arduino-compatible board designed by Sparkfun, https://www.sparkfun.com/products/11098

[2] http://arduino.cc/en/Main/ArduinoBoardProMini

This has 8 more pins than the LaunchPad and is a bit cheaper: https://analog10.com/store/BOB-G2553-28.html You can drive motors from those pins while keeping your P1 free for comm peripherals.

An ATTiny85 in DIP also runs unassisted. That's not the point of this board, though.

I think it does.

BTW, Teensy 3.0 just recently came out : http://www.pjrc.com/store/teensy3.html

It's only slightly bigger than the 2.0, but you get 3 more PWM pins (10 total) and 34 I/O and 3.3V out.

It looks even more inspired by the DigiSpark: http://digistump.com/products/1

Good question. The type USB implementation is important. There are lots of things you can't do well if the CPU is managing the USB connection in firmware at the same time as running the implementation.

I own two digisparks, and I think the main improvements are the 3.3V/5V and mounting holes. I'm still glad to see more devices filling this niche.

Limor (and the company she built) has been producing microcontroller and Arduino kits & boards like this for a long time. Digispark reflects a lot of her original work. This is a good thing!

The Arduino platform has already largely solved that, though. Almost all of their products (besides a few "Pro" models which are TTL-serial only) have USB ports on board.

Well the interesting things probably involve using the SPI port to talk to some memory expansion.

At Google, Henner Zeller built a circuit pretty much like this that drove an RGB LED and was used for Test status 'orbs'. Basically with a bit of code your orb would turn red if your tests started failing in the continuous build.

I used one to add a foot 'key' to my setup when playing World of Warcraft (it was my push to talk switch) but it could have been anything, it pretended to be a USB keyboard with one key :-).

I've seen them used to pretend to be a mouse and move the mouse around (a 'jiggler') so that a machine wouldn't kick in the screen saver.

All various sorts of things you might want to do with a bit of compute.

Head over to http://hackaday.com or http://makezine.com and search for Arduino or ATMega or microcontroller -- you should have a ton of hits describing various projects.

Compared to an Arduino, this is smaller, consumes less power and has a "standard" layout and costs about 1/3rd of an "official" Arduino. The downsides are that there's less memory and less cpu perf, there are less I/O pins, but a lot of (practical, non-beginner) projects don't need that many pins. A highlight would be hardware SPI and I2C support, which are communication protocols for small gadgets (the AVR chip in Arduino has I2C/SPI but you can't use it from Arduino code, you need to write C) and PWM (pulse width modulation) which is a pseudo-analog output signal used to control things like servos.

So what could it be used for? Get a bunch of sensors and actuators that communicate with SPI/I2C/PWM. Think about things like accelerometers, gyroscopes, proximity sensors, liquid crystal displays, motor controllers, servo motors. Now plug them together and build just about any gadget you can imagine.

It's better than an Arduino if you're short on space, weight or power consumption. Things like tiny flying machines or wearable gadgets.

If you're a beginner looking for your first microcontroller platform, the Arduino will probably be easier to approach.

This board is pretty minimalistic. It has five general-purpose I/O pins that you can use to read and write logic-level signals (either 0V or your supply voltage, usually either 3.3V or 5V). Three of those also have analog-to-digital converters, so you can use them to measure voltages in that whole range. Two of these pins have hardware for generating PWM signals, making them useful for motor control. Three of these can be used for an SPI or I2C bus.

By itself at can't do those. If you connect it to a WiFi or Zigbee module using SPI it can, but for WiFi you'll probably want to buy a more powerful microcontroller board anyway.

One obvious advantage is that it's cheap enough to use as-is. One of the things that keeps me from caring much about Arduino is that it's too expensive to use for anything but experimentation: if I'm building more than a one-off, I'll always do a custom PCB.

For reasonable volumes that's still probably the best approach, but at $8 a pop this is perfect for throwing together some quick project.

By way of analogy: to me, an Arduino is a breadboard. If I use one at all, it's to play with a first concept, and certainly not for any kind of permanent use. If that's true, then this is kind of like solderable perfboard: not optimal, but good enough for many things.

It's attractive because of the convenience it provides.

$8 for an Arduino compatible microcontroller with a battle-tested PCB, all pre-assembled is an amazing deal.

Sure, you could breadboard your own for cheaper, but you wouldn't be saving a whole lot in the scheme of things.

It's a relatively huge amount of power in a tiny package, ready to roll. Many digital logic tasks that used to take a number of TTL/CMOS logic chips, or other devices can now be done in one inexpensive package.

A simple example: every week it seems, on the electronics forums, someone will ask how to do a simple, or a complex timing task and they will be pointed at various logic, or 555 timer chip designs.

Using something like this not only makes those projects simple, it provides a common frame of reference. If I can say to someone "go buy a Trinket from Adafruit and load this code into it and it will work cause I already tested it on my workbench" that provides a tremendous value because both I and the person I'm talking to online are working from a common platform.