Since last January, we were experiencing strange unexpected power loss on the server. We thought it was caused by a recent kernel upgrade of the Ubuntu Server 9.04 distribution. Some posts in dedicated forums stated that there could be issues with the ACPI support on ION-based boards (ION is NVIDIA chipset that runs on the Acer Aspire Revo R3600).

After weeks of investigation, we found that the issue was caused by the thermal protection of the CPU. In certain condition (but we were not able to determine what was the actual reason), the operating system powered off the server to protect the hardware. However, there was not relation between CPU load and unexpected power off.

We moved from software to hardware. Apparently there were no issue with the CPU fan. Apparently. We powered off the server for about one hour, just to replace some cables, then the server was powered up again. After a while, the was a strange noise coming from the server: some “crick”, “crack” on the plastic covers. In less than a quarter the server case was very hot and the fan was not working. After a while, the fan started to rotate very slowly, but the board was so hot that Ubuntu powered off the system.

We opened the case and we discovered that the fan was not working properly.

The REVO opened

After a power cycle, the fan may rotate very slowly or even be completely blocked. However, at the very start of the system (where the fan is powered-on for a bit, without any speed control), it always rotated at maximum speed. We deduced that there was an issue with the fan speed control.

The fan removed from the heatsink

Therefore, we decided to completely exclude the fan control (which is performed using a PWM signal on the blue cable) and to leave it to run at maximum speed.

The BLUE cable has been cut: no power speed control will stop the fan!

The QuadraSpace server is now much more noisy, but no more unexpected power-off have been experienced.

Keep sensing, now…

XML Schemas are available on the Specification page.

The entire development environment is opensource software and the Waspmote development kit includes demo boards for lot of sensors, including GAS, position and others, with lots of communication options (GPRS, 802.15.4, ZigBee and long-range radio).

We intend to adopt Waspmote as reference platform for upcoming first QuadraSpace system prototype, which we expect to present in early 2010.

Great job, Libelium! Keep running!

Web of Things whitepaper v1

This document is a bright and clear analysis of what the Internet of Things is moving towards the Web 2.0 paradigms. Vlad and Dominique are doing a very good job to define concepts and approaches of the Web of Things, focusing more on what it implies to the Internet world instead of working on a specific protocol or technology.

We really appreciate their effort and, as QuadraSpace project team, we “virtually sign” the Web of Things Manifesto. Quoting Vlad and Dominque doc:

[...] little attention has been paid to the development of simple and … functional open systems that focus on sharing and reuse of physical things. [...] The creation of a global and flexible eco-system of connected real-world devices calls for a common ground that allows physical objects to interact and exchange information seamlessly [...] As seen with the success of several Web 2.0 applications, massive projects have been developed cheaply by fostering collaboration and sharing of information. Open access to data through services onf the Web has enabled information to be reused across independent system, therefore has lowered the access barrier that allows people to develop their own applications. For all these reasons, we foster the development of novel composition platforms for networked objects by leveraging as much as possible the existing Web and by extending the current Web to include the real-world. Creation of a new generation of Web-enabled devices will result in the Web of Things, and in our vision the future Web will be a collection of devices that can be (re-)combined at runtime to solve any task. Our research is focused on the development of composite applications on top of the open and simple standards that made the Web so
successful (REST, XML, HTTP, or Atom) to interconnect physical devices.

We hope QuadraSpace will effectively contribute to realize that.

First action on backend-side is the adoption of a Acer Aspire Revo R3600, an “eco-computer” based on Intel’s Atom 230 processor and NVIDIA ION platform, as first QuadraServer node.

This small computer runs with a 65W power supply for its internal components (everything but an optical drive); in current QuadraServer setup there are also two external hard drives used respectively for the RAID-ed data storage and backup for internal system disk. Total power consuption will be about 100W. Having QuadraServer always-on 365/24/7 requires 0.1 * 24 * 365 = 876KWh, that produce about 470 kg of CO2 (just for reference, a typical SUV equipped with a 3 litres engine, produces the same amount of CO2 to run less than 2000km!).

Next week we will setup the server and we hope to have the QuadraServer instance up&running in a couple of weeks.

Stay tuned!

Stay tuned

First of all, we’d like to thank all friends that have sent their comments about previous drafts of QuadraSpace: your help has been valuable for improving the protocol, include features you expected and to find pitfalls in the specifications. We have carefully taken into account some considerations about REST approach (thank you Emanuele), and we finally changed QuadraSpace to support all main HTTP methods (GET/POST/PUT/DELETE) but to guarantee access to the backend also for those devices (Java ME CLDC/MIDP in primis) that lack full HTTP client in their standard library. We will give ore details about that in upcoming articles. Finally, each event has a type, that can be “sample” or “heartbeat”. “Sample” is the event as it was originally described (a notification of some data read by a sensor). “heartbeat” is a “still-alive” message sent by the mote to notify that it is fully operative (thank you Dadaista for reminder!).

The first draft was 47 slides long: the new 4th draft nearly doubles that size (84 slides)! QuadraGrowing!

Find it at:

http://quadraspace.googlegroups.com/web/qs_protocol_DRAFT4.pdf

or browse it on this web site:

Find it at:

http://quadraspace.googlegroups.com/web/qs_protocol_DRAFT3.pdf