A Digital Sign Of The Times

Going With A Wireless Sign The EX motherboad has a single PCI slot. Had I used 802.11b/g then Logic Supply would have been able to provide a solution that would work within the confines of the GS-L05 case. Unfortunately I like to push the limits and wanted to stream HDTV content. For this, we turn to the pending 802.11n standard that will push data at speeds in excess of 300Mbit/s. Streaming video to multiple wireless digital signs will easily overwhelm 802.11b/g solutions. Belkin provided their F5D8231-4 N1 Wireless Router for this project. This triple antenna system employs MIMO (Multiple Input Multiple Output) spatial multiplexing. It can push data at speeds up to 300Mbits/s. It supports NAT (network address translation) and it can act as a firewall between a cable or DSL connection and the rest of the network. It incorporates a four port 100BaseT hub. It provided a great way of linking our lab network to the digital signage system. Unfortunately, the F5D8001 N1 Wireless Desktop Card was just a fraction of an inch too high to fit into the GS-L05 case. We did test it with the EX motherboard but you will need to utilize a larger, more expensive case like Logic Supply’s GD-L01. This approach adds space for more and larger hard drives as well as an optical drive, but tends to be overkill for this application. Also, the F5D8001 has external antennas. This not really a problem but makes it comparable to the solution we chose, Belkin’s F5D8051 N1 Wireless USB Adapter. The image shows the adapter with its desktop USB stand. The stand itself contains only the USB cable and connection. We actually used a standard USB extension cable and mounted the actual adapter, with a built-in antenna, to the top rear of the N3752w display with some Vecro. The USB interface is not quite as capable as the desktop card but the differences were not noticeable in our test environment. Still, we expect the desktop card to perform better when the router is a bit farther away. Digital Signage Software The initial setup is most easily done with a USB optical drive attached to the system. It is possible to copy an image onto the flash drive on another system but this tends to be rather tedious in terms of connection since it requires external power. It also means opening the system that Logic Supply sent. A USB keyboard and mouse were used as well. I loaded a stripped-down version of Windows XP for the project. I didn’t pull out my development tools to install Windows XP Embedded although this would likely be a good alternative for this type of application where you do not want someone playing with the system. If you do use a stock version of Windows XP, then make sure you disable the swap file since there is usually no need to thrash the flash memory in this type of application. I also disabled most of the automatic update features and notification since the system will usually run a dedicated signage application that displays data using a fixed script or streams data via the wireless network. Either the Windows XP remote desktop or VNC can be used to provide remote management. This will typically be the mechanism for performing maintenance since the case is normally put in an inaccessible spot without a keyboard or mouse. I also went with Windows XP as a software platform because of driver considerations. Belkin currently has drivers for Windows XP and Vista. Linux drivers may be available but not at the time I started the project. Of course, this would not be the case with the 802.11b/g alternatives including those from Belkin. I actually would have preferred using Linux for this project for its ability to set up a VNC that operates in the background. This would allow changes using a GUI while the main display runs. This can be done using Windows but the setup is a bit more difficult. The other alternative is to use a command line interface like SSH. This is available for both Linux and Windows. Of course, for general user configuration a web interface is the preferred mechanism. Running a web server on Windows or Linux is a trivial exercise. I won’t get into the actual signage related applications because of the variety of options available. It can be as simple as opening an application like Windows media player to stream data via the network connection. Overall, the EPIA EX motherboard has plenty of horsepower to deliver the multimedia content that this type of application requires. The Emphase flash memory proved to be the best option for this type of application. Logic Supply can deliver fully-configured systems made-to-order. All you need to do is add a display. The Mini-ITX approach to digital signage provides a quick way to deliver custom solutions. It’s not the only alternative, but it’s significantly less expensive than building a custom board and system. Related Links Belkin Emphase Logic Supply Microsoft Viewsonic VIA Technologies