A cable box becomes a network time display


In 2011 [Erkki]‘s DVB box gave up the ghost. It had been a fixture of his media center for quite a while, decoding cable and recording shows faithfully for years. A flaky power supply will bring down the mightiest machine, though. and the Topfield box eventually found itself in disuse. One thing [Erkki] liked about this cable box is its wonderful green LED clock – even after the box had been declared dead, he still used it as a clock. Not wanting to keep a faulty machine on life support, [Erkki] decided to strip the guts and replace them with a networked Arduino that receives time over a network

[Erkki] originally used an Arduino and an ENC28J60 Ethernet module to receive time from an NTP server and spit it out onto the LCD display. A full Arduino for this kind of job, especially one that’s a more or less complete project, is a bit overkill so [Erkki] designed a PCB to put his ‘duino to better use.

One interesting bit about this build is that [Erkki] found it completely broken one day. Figuring this was a problem with the microcontroller, he first fried the ATMega with 9 volts – the reasons escape us, however – and started work on programming a new chip. After looking at different ports on his NTP server with a microcontroller, [Erkki] realized he had reset his network switch recently, meaning the previous microcontroller was working perfectly.

In the future, [Erkki] hopes to add some new features to this 8×4 seven-segment display sitting in a large box; something like reading off the temperature, checking IRC and his physical mailbox, and notifying him when someone is at the front door.

Embedded web server is all about clever formatting


Take a look around here and you’ll find all kinds of embedded web servers. This one doesn’t look all that interesting, especially because it’s just a NIC plugged into a development board. But for us the interesting part is in how [Andrew Rossignol] chose to format the webpage assets to best utilize the under-powered server.

The project was spawned as part of a class in Internet Embedded Systems which [Andrew] is taking. The board has an ATmega16 microcontroller and he’s using the ever popular ENC28J60 on that Ethernet adapter board. The TuxGraphics TCP/IP Stack takes care of communications with the network.

One constraint which [Andrew] imposed upon himself was to use just a single response which the available RAM limits to about  700 bytes. Any decent webpage needs to have at least some graphics but that’s tough with the size limit. He managed to display an AVR logo by optimizing an SVG in Inkscape then stripped the rest of the cruft using VIM (explained in the demo after the break). With that piece of Linux-fu in his pocket he set to work streamlining the CSS file. The webpage isn’t just static either. He displays the server up-time and even allows the relays and LEDs on the Olimex board to be controlled.

Despite the limitations of the ATmega family they still seem to do some amazing Internet-connected stuff. Here’s one used as a Minecraft server.

[Read more...]

Online radiation monitoring station


This is a Geiger counter which charts its readings on a webpage. [Radu Motisan] put a lot of time into the build and it shows. This thing is packed with features and the hardware choices were the best combinations found through several iterations of development.

In addition to radiation levels the sensor unit takes several other measurements. These include temperature, humidity, luminosity, and barometric pressure. All of the sensor data is monitored and gathered by an ATmega168 which can be charted on a webpage with the help of an ENC28J60 Ethernet chip. The collection and display of this data is detailed at the post linked above.

For those interested in the hardware development, [Radu] published many updates along the way. These are available in his forums posts, as well as his build log. He doesn’t have any videos of his recent work, but way back in May he did publish a clip (found after the break) which shows the testing of different Geiger tubes.

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An STM32 processor powers this PC

This 32-bit computer is a project [Bogdan Marinescu] built as a contest entry. Sadly he didn’t win, but he did do an excellent job of documenting the build. Having seen several other home built PC projects we’re familiar with the challenges that go into such a thing, and he found some great solutions to each of them.

He started with an STM32F103ZET6 chip. This is an ARM Cortex-M3 processor which brings a lot of power to the playing field. That being said, generating a VGA signal would pretty much zap the usefulness of the chip for other processes so he offloaded that work on a separate Propeller chip. A microSD card serves as storage for the machine, which runs eLua (embedded Lua programming language). There is 1 MB of external RAM and a PS/2 port for keyboard interface. The system is networked thanks to an ENC28J60 Ethernet controller. Don’t miss the video after the break where you can see several demos running on the system.

[Read more...]

Cheap as chips Arduino Ethernet shield

It’s no secret that Ethernet shields for the Arduino are a little expensive. With the official Ethernet shield selling for about $50 and other options not much cheaper, there’s a lot of room for improvement for Arduinofied Ethernet. [Boris] over at Open Electronics has a solution to this problem: his Ethercard powered by a $3 Ethernet controller.

The Ethercard uses the Microchip ENC28J60, a through-hole Ethernet controller. There isn’t much else on the board apart from an RJ45 jack, caps, resistors, and a cheap buffer chip. This board was designed to be easily produced, and we’re thinking it might be possible to etch this board at home.

There are a few drawbacks to this ENC28J60 Ethernet shield – the official Arduino Ethernet shield has a 10/100 Mbps connection where the Microchip-powered shield is limited to 10 Mbps. Given the reduced cost, ease of assembly, and the fact that it’s pretty hard to saturate a 100Mbps connection with an Arduino this flaw can be easily ignored.

Pretty neat, especially considering how much you can do with an Ethernet connection on your Arduino. Files and code available in the git.

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]

Commandeer X10-based home automation with your favorite microcontroller

X10 has been around for a long time. It’s the brand name for a set of wireless modules used to switch electrical devices in the home. There’s all kinds of different units (bulb sockets, electrical outlets and plug pass-throughs, etc.) and they’re mass-produced which makes them really inexpensive. Whether you already have some X10 controlled devices or just plan to add them later, we think you’ll find [Jeff Ledger's] post on controlling the system with a Propeller chip interesting. The technique is not Propeller specific and will be simple to port to your microcontroller of choice.

[Jeff] got his hands on an X10 Firecracker. This provides a DB-9 serial connection meant to be used for computer control. But the interface is so simple all you need is two I/O pins feeding the level converter circuit seen above. You can get the TC4427 for less than a dollar, and the Firecrcker module for as little as $6. Since [Jeff] has already covered adding Ethernet via a ENC28J60 he goes on to detail a web-server that lets him switch his devices, all served from the Propeller chip.

Here’s a different ENC28J60 Ethernet tutorial for those interested in webpages from microcontrollers. And then there’s also a ZigBee home automation project if you’re not warming up to the idea of using X10 modules.