Embedded Linux meets Arduino with the Rascal Micro

Behold the Rascal Micro. It’s running embedded Linux and has a dual-row of pin headers which probably seem pretty familiar. The idea here is to bring Arduino hardware (ie: shields) to a party with a powerful web server.

The image above is the beta version of the hardware. What’s being shown off in a recent Engadget demo is a version that slides two USB ports in between the barrel jack and the NIC. This makes it easy to jump over to wireless with the use of a USB dongle, or you can figure out what other peripherals you want to include in your project.

The novelty here is that the web server included a built-in editor. So not only can it serve you a webpage to control hardware or display sensor status, but it will let you edit the interface without needing to reflash anything.

The price rings in somewhere around $100-150, and like the popular Raspberry Pi board, you can’t get your hands on it right now.

Building the backend of Internet controlled devices

[Adam] and [Jeremy] took on the challenge of designing a system that would make it easy to control appliances from the Internet. We’ve seen the concept many times before; it involves some method of switching mains power and connecting that mechanism to the Internet. This design is both well planned and nicely executed.

We’re always very interested in the power switching for a project like this. It’s good that an approved electrical box houses all of the high-voltage parts in the project. Here a GA8-2B02 solid state relay switches power between the incoming cord and the two outlets. We didn’t get a look in the box, but hopefully there’s a partition between those wires and the low-voltage control wiring which uses a standard 3.5 mm audio jack as an interconnect.

An ATmega644 drives the control signal for the relay. It’s connected via Ethernet cable to the Internet through the use of an ENC28J60 chip which takes care of LAN communications. This is essentially a light-weight web server that will be easy to adapt to receive commands from just about any web-connected sender.

[Thanks Bruce]

Over-the-air FM radio gains Internet control

[Old bit collector] is giving up control of his radio dial to the Internet. He combined a couple of Parallax products which now allow him to tune, adjust volume, and toggle the power for an FM radio receiver.

The setup is pretty simple. An FM receiver module is mounted in the breadboard seen above which helps to break out its control pins. Those are connected to a Parallax Spinnarette web server board. It’s auxiliary I/O pins are controlled via a web interface that he set up and plans to operate with the browser on his Android phone. But as you can see after the break, any web browser works as long as you know the correct address.

This is pretty good if you’re on a quest to make everything controllable from your smart phone. But we would love to use the concept to make our own streaming radio. You’d be able to tune in to all of your local stations from anywhere in the world.

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DIY PIC development board and web server

websd

Inspired by a project featured here on Hack-a-Day, [arthurb] bought himself a PIC 24F and started experimenting once he learned the ins and outs of programming the chip. Using a breadboard and a nest of wires was fine for his first few projects, but as he advanced, he began to feel the need for a full-fledged development board. With a list of required features in mind he got to work, constructing a well thought out board as well as a handful of expansion boards that can be used for various other projects. His main development board includes Ethernet connectivity for use with his web server software, the ability to utilize an SD card for storage, and a USB port for programming. His expansion boards include a temperature sensor, a numeric touchpad, as well as a video output module. Overall it is a pretty impressive build, considering he had never programmed a PIC before starting this project. All of his boards are thoroughly documented, and he has included plenty of source code in hopes of helping other individuals just starting out in PIC programming.

You can see his web server in action here, but keep in mind that it is running off a PIC, so please be courteous in your usage.

Chumby webserver using upgraded internal storage

The Chumby One has an internal SD card offering a fair amount of storage. [Kenneth Finnegan’s] came with a 1 GB card that had about 500 MB left over which he filled with a collection of MP3s. But he wanted to do more and so installed a pre-compiled version of lighttpd to act as a web server. The problem is that this binary requires a thumb drive to be plugged in because it maps the storage directory to the mounted USB folder. He wasn’t happy with that so he upgraded the internal SD card and rolled his own webserver to run from the internal SD card.

The upgrade involved going from a 1 GB to an 8 GB microSD card. In order to run the webserver internally he needed to recompile lighttpd to use a different root directory. This meant setting up an ARM cross-compiler and eventually finding a new place for the start up script. The location change for the ‘lighty’ directory leaves us wondering if a symlink couldn’t have solve the problem without recompilation. But we don’t have the hardware on hand to try this out ourselves.

But if you want to give it a shot, check out [Bunnie’s] post about Chumby-based hardware. Looks like you can head out to the big-box store and have one in hand without shelling out too many clams.

How-To: Web server on a business card (Part 2)

This mini web server is slightly smaller than a business card. There are a lot of tiny one-board servers out there, but this is probably the smallest you can etch and solder at home. Unlike many embedded web servers, files are stored on a PC-readable SD card, not in a difficult-to-write EEPROM. Read on for the web server design, or catch up on PIC 24F basics in the previous article: Web server on a business card (part 1).

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How-To: Web server on a business card (Part 1)

For years, Microchip PIC microcontrollers dominated; PIC16F84 hacks and projects are everywhere. The 8-bit 16F and 18F lines are supported by several coding environments and easy-to-build serial port programmers. Microchip’s 16-bit PIC24F is cheaper, faster, and easier to work with, but largely absent from hacks and projects.

We recently used a Microchip PIC24F microcontroller in a mini web server project, but didn’t find many introductory references to link to. In this article we’ll cover some PIC 24F basics: support circuitry and programming options. We’ll also talk about our favorite features, and how we figured them out. Our next article will outline a web server on a business card based on the PIC 24F.

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