One of the directors wanted to have a wallboard displaying real-time numbers from our new VoIP phone system. We had a web page which could show the stats, so we now had to decide how to get these onto a wall-mounted display in the office.
The display part was easy, there are quite a few 32 inch or larger LCD TV systems with HDMI input. The question was what to use to display and update the web page.
At first we considered setting up a PC to do this but even the Intel NUC devices are quite expensive – £250-plus for a device and a disk. They are also much more powerful than we need.
My colleague working on this project is looking at the Google ChromeCast device, but this is designed for media streaming rather than web pages. I decided to explore the Raspberry Pi as an alternative.
To be honest, I’d been itching to mess about with a Pi since they came out. But with so much else to do I couldn’t justify the time to myself. This was a good opportunity to experiment with a specific, worthwhile goal in mind.
I chose Pimoroni as my supplier as they had a good selection of starter kits. Our “production” unit would consist of a Pi model B, a case, 8GB SD card, WiFi dongle, 5v USB power adapter and a short HDMI cable.
This comes to £67 including VAT in the UK – a lot less than the NUC option. Add that to a 32” Samsung TV for about £219 including VAT. These are excellent as they also have a powered USB 5V connector – so the Pi runs off the TV power supply.
So a wallboard system for less than £300! A wall mounting bracket is extra – these vary from £10 upward, so we might just break the £300 limit for that.
I got two “production” units and a “Deluxe Raspberry Pi Starter Kit” which includes a simple USB keyboard, mouse, USB hub – this one was to act as our development box.
Configuration and Setup
The main requirement was a hands-free boot-to-display operation. Fortunately someone else had done the heavy lifting for this part of the design by configuring their Pi to act as a wall mounted outlook calendar. A tip of the hat to Piney for his excellent guide.
Once I had a working development system, I purchased a USB card reader (that supports SD card format – almost all do) for my PC and installed Win32 Disk Imager. I copied the working SD card from the development Pi to an image, and then wrote this image back to the two production SD cards.
I had so far had this on my office WiFi on a computer monitor, so I unhooked the development setup, and went into my house, where the children’s 42” TV sat in their den, practically begging me to try it out.
I was impressed that I didn’t need to touch the screen setup for the HDMI to work correctly. I had to reconfigure the WiFi, but once that was done I could plug the Pi directly into the TV’s powered USB connector, and the HDMI cable.
Installation at site isn’t totally shrink-wrap unless you know the WiFi configuration in advance. Our production Pis were delivered to my office and our excellent support tech Cristian used a USB mouse and keyboard to configure them with the correct WiFi setup and key. He then mounted the two Pis behind the monitors (you could use Velcro tape for this), connected their USB power to the monitor USB output and the HDMI to the TV’s HDMI.
The TV is switched on in the morning, which powers up the USB port. The Pi boots up directly into a full-screen display of the web page that shows our call stats.