The Arachnio is something I've been working on for a few months, and it's now up on Kickstarter! The subject line is the elevator pitch -- it's the first Arduino Micro variant with onboard WiFi, via the increasingly popular ESP8266. It's pin and software compatible with the existing Arduino Micro, and only slightly larger to accommodate the antenna. Naturally, it's entirely open source (unlike other Arduino variants with on-board WiFi, such as the Yun).
Putting WiFi together with the Arduino, especially in a small, low power package, is a really natural fit. For example, every Arduino-powered robotics or LED project is made immensely cooler by having the capability to control it from your smartphone baked right in.
Since the Arachnio is small and low power, it also makes a great brain for a remote sensor. The fact that it's an Arduino variant makes the programming simple and the wealth of on-board peripherals make it straightforward to connect most common sensors. WiFi lets your remote sensor connect to your phone or tap into the Internet to get the data back to you.
Including both the ESP8266 and the 32u4 on a single board provides a much more useful package than either one alone. The capabilities of the ESP8266 and the 32u4 complement each other nicely. Here are some of the advantages of the Arachnio over an ESP8266 module alone:
- More GPIO -- The Arachnio has more than twice as many GPIO pins available as any ESP8266 module.
- More ADC -- The Arachnio has twelve usable analog to digital channels versus a single channel for an ESP8266.
- Hardware PWM
- Dedicated hardware I2C and SPI interfaces
- Full Arduino library compatibility
- Native USB -- The Arachnio's ATmega32u4 provides a full speed hardware USB interface. The Arduino environment provides libraries that make the USB function as a serial port, a mouse, or a USB keyboard.
- Breadboard compatible -- The Arachnio's headers are on 0.1" centers and narrow enough to fit into standard breadboards with room to plug jumpers in on both sides.
And of course the ESP8266 provides WiFi and, for more advanced users, a more powerful processor to use for more computationally intensive tasks.
All of the vital statistics can be found on the Arachnio product page.
I decided I also needed a couple of expansion boards available immediately in order to really make it sing. The first is of course a prototyping board, the ArachnoProto.
The ArachnoProto is designed to fill the same role as an Arduino protoshield. It has two large prototyping areas, a programming header, mounting holes for 3mm screws, two LEDs and a pair of push buttons.
You can tell this is a prototype because the board house managed to mess up my logo on the board.
There's also another less obvious feature here, which is that this board has been assembled with bottom-entry headers on the underside. The upshot of this is that the assembled Arachnio + ArachnoProto is much thinner than with conventional headers. These headers are included with every ArachoProto.
The Arachnode is designed to give users a way to quickly build flexible and independent sensor and network nodes. It has a solar battery charger, a real time clock, a microSD card slot, and an optional crypto module.
I just got a new release candidate board which has some tweaks arising from the testing we've been doing, mostly to improve fit and clearances. This is the first one that's really feature complete, since I've been focusing on the Arachnio rather than the Arachnode for most of my development. I haven't had time to assemble the new ones, but here's the bare PCB:
One of the things I've enjoyed doing that I wish more Kickstarter creators would do is post Instructables for the Arachnio. I've only got two of them up so far, but they address questions that people have asked me about using the Arachnio.
Please don't forget to back the Arachnio on Kickstarter so we can make it a reality!
Thanks to gorgeous weather here in Seattle yesterday, I was able to get some great pictures of the ArachnoProto and Arachnode prototypes.