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The headline tells the heart of the story -- the Arachnio is an Arduino Micro variant with onboard WiFi via the increasingly ubiquitous ESP8266. As well as the core board, I'm also putting together a sensor node board, the Arachnode, and a prototyping board, the ArachnoProto.
The Arachnode incorporates a microSD card, a solar battery charger, a real time clock, and a crypto modules.
The ArachnoProto has plenty of prototyping space, an ICSP connector, two LEDs, and two pushbuttons.
I'm working on wrapping the Arduino WiFi interface around the standard ESP8266 AT commands so the Arachnio can be used with all of the existing network libraries for the Arduino. The hardware is set up such that the 32u4 can be programmed over the air, but that's going to require some more firmware work on the ESP8266 side.
I've read a number of posts complaining about the stability of the ESP8266 modules on the market. The software has been rapidly improving, but I suspect there are hardware issues with the modules as well, specifically in the decoupling capacitor. The suggested decoupling capacitor is a single 10 uF capacitor with no smaller caps. This is not recommended technique -- see http://http://www.analog.com/media/en/training-seminars/tutorials/MT-101.pdf for a detailed description of how to do it right. I'm working on improving the decoupling on the Arachnio to address these problems.
Please support the Arachnio on Kickstarter http://https://www.kickstarter.com/projects/logos-electro/arachnio and check out this Arachnio family picture:
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I have some updates...
-- First, prettier pictures; check them out here: https://www.kickstarter.com/projects/lo ... ts/1204518 (https://www.kickstarter.com/projects/logos-electro/arachnio/posts/1204518)
-- Second, I've put up a couple of instructables: https://www.kickstarter.com/projects/lo ... ts/1196236 (https://www.kickstarter.com/projects/logos-electro/arachnio/posts/1196236) and https://www.kickstarter.com/projects/lo ... ts/1192624 (https://www.kickstarter.com/projects/logos-electro/arachnio/posts/1192624)
-- Third, my friend Jeremy put together a small rover powered by an Arachnio. It serves up a javascript joystick to any device (such as a phone) that connects to it, allowing you to drive it around. I hope to have some pictures and video this weekend, along with an Instructable.
-- Fourth, I expect to have the prototype boards implementing my decoupling updates in hand on Monday. I'll be setting up an uptime contest between the current iteration and the new iteration using data.sparkfun to see if that does anything to improve the stability. Naturally, that will become its own Instructable.
What is the idea behind the use of the atmega?, the esp itself is an 80mhz mcu?
The combination offers a bunch of advantages over just an ESP8266 module:
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 -- Since the Arachnio uses an AVR processor, all Arduino libraries will work out of the box without porting.
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 all standard breadboards with room to plug jumpers in on both sides.
Code isolation -- Your code doesn't have to worry about servicing the network stack.