Sometimes it feels like technology is everywhere and then at other times, it feels like there is still a long way to go. It’s easy for us to forget that it isn’t always commercially viable to make everything ‘next-gen.’

One area where those two distinct elements - cutting-edge technology, plus tried and tested business practices - are coming together though is with regard to digital out of home (DOOH) advertising. As the name suggests, this is any form of advertising that employs digital technology in an ‘out of the home’ environment. Think of moving billboards in public areas, or better still, the digital signage experience that Tom Cruise’s character gets in the film “Minority Report,” where he is identified by a retinal scan and shown customised promotional material as he walks past.

OK, so we may not be there quite yet, but the introduction of beaconing technology using Bluetooth is certainly a step in that direction, which got me thinking about how it could be used for DOOH in a way that might benefit more than just the advertiser.

What came to me, as I was walking down a busy road in London, was the idea of a “beacon backpack.” The basic premise here is that the backpack would have a built-in display that automatically played an advert for one of the retailers in the local proximity as the backpack wearer walked down the street.

As the wearer of the backpack, you would be largely unaware of what’s being displayed, but anyone following you would see a vibrant and eye-catching display of special offers and suchlike. It could even have a flashing arrow pointing toward the shop in question. It’s kind of an upgraded version of the person who stands in the street in all types of weather holding a sign saying “This Way To The Best Chips in Town!”  

The interesting twist here is that the backpacker could get a share of the advertising revenue, based on the number of people that see the ad. This could be great for students looking for some financial help with their tuition fees, for example. Drop in a smidgen of AI and the advert could even react when people look at it - bringing a whole new dimension to the experience. Really, the possibilities are limitless, and it all starts with a simple Bluetooth beacon.

This got me thinking, if I were to design a Bluetooth-enabled DOOH backpack, how would I do it? I’d assume it was going to be battery powered, for obvious reasons, which would consequently limit the amount of power that the system was able to draw. It would need to have Bluetooth connectivity to receive beacon messages from the shops paying to advertise. The actual information being rendered on the backpack display could either be streamed over a wireless internet connection in real-time, or it could simply reference a stored file downloaded to the backpack when convenient (such as at home over Wi-Fi, while it is in the process of recharging).

There are quite a few possible solutions out there, but the one I think will work well in this application is the ESP32-SOLO-1 from Espressif Systems. It integrates both Wi-Fi and Bluetooth functionality, with support for beaconing. Best of all, it is offered at a very attractive price point. This really puts it in the area of a consumer wearable device, and with a sleep current of just 5µA for the host SoC (the ESP32), it is seems to be very close to ideal. There is also support for an LCD screen, a camera and an SD card (which could be used to store the required advertising data).

The ESP32 can support a 3.2” LCD over a SPI interface. While this isn’t huge, it would probably be big enough to get the attention of someone close by, and with a camera included it would be relatively easy to “see” if anyone was looking at the display. Electronic Assembly offers a portfolio of suitable LCDs (though there are, of course, plenty of alternatives out there too), while camera modules aimed at wearable applications are available from a variety of different manufacturers.

Now all I need is for the DOOH industry to recognise the potential of the idea and build the infrastructure needed to support it. I wish I had precognitive siblings who could tell me when that might be likely to happen.