Memoto - Narrative Clip

Swedish company Memoto developed the Narrative Clip in 2012. A tiny portable 'life blogging' camera, the wearable tech features a tiny GPS chip to record location data.

Find out how the designers were able to create a test environment enabling them to virtually test their devices anywhere in the world.

The Narrative Clip is a typically innovative wearable, and one of the new wave of 'lifelogging' devices now finding their way into mass production. It is a tiny (36 mm x 36 mm x 9 mm) five megapixel camera with enough memory to store four thousand images and battery power for two days of use.

Designed and manufactured by a Swedish company originally called Memoto, who sourced crowdfunding to get the project off the ground, the Narrative Clip is small and non-intrusive to the point that it can be easily worn on one's clothes.

It is such a neat design that it has no buttons at all, only requiring to be put face down to enter standby mode. One of the standout features of the device is that the miniature enclosure includes a custom GPS engine and antenna, allowing for every image it takes to be geotagged. Future development of the cloud-based storage of these images will allow for searching by location.

The challenge faced by Memoto's designers was how to test their location-enabled camera when its diminutive design meant physically connecting a GPS simulator was not an option whilst real-world testing at locations around the world was financially and time prohibitive.

Narrative Clip from Memoto

The Solution

Bjorn Wesen, one of the developers on the project, explains how they got started:

"Because GPS does not work well indoors, at first we simply needed a way to test reception inside our office. Since we're not based in California, we can't just move the office outdoors! We started with a simple GPS-repeater, that is, an antenna mounted outside and an amplifier and re-transmitter indoors. This worked fine for some of the engineering tasks, but is not sufficient to reproduce testing scenarios or comparing sensitivity between different antenna-solutions, so we started looking at GPS record/replay products and that's when I contacted Racelogic."

This is a problem often faced by anyone developing a product that will include GPS: whilst it is entirely possible to walk outside and check that a signal is obtained, as Bjorn points out, it doesn't go far enough. The satellite almanac is constantly shifting, as are the signals themselves as they are 'bent' travelling through the ionosphere. Consistency is therefore hard to maintain, so a LabSat is the perfect solution.

Martin Källström, CEO and co-founder, in an interview with Slashgear.com in October 2013, gave an insight into the kind of issues they encountered:

"In the first integration, we were planning to use a small GPS antenna that was 2 x 3 mm and actually uses the PCB as the real antenna, but that didn't work at all. So we worked with antenna experts in Sweden on a wire antenna, that goes along the top of the camera...And that antenna worked excellently inside, in the lab. Even inside the camera, with the PCB, it was excellent. And then, when we disconnected it from the lab equipment and put it inside the camera, and turned it on, it didn't work at all. There was no signal coming out of the GPS antenna.

So we wired the antenna not into the PCB but into the lab equipment, and we could see that when the electronics of the camera was shut off, the antenna worked perfectly; when the camera was turned on, the antenna didn't work at all. There was a signal there, but it was completely drowned out with noise. The casing was a perfect echo chamber for the electronic waves, so we had a completely abstract process trying to remedy it by moving the components around the PCB."

EOL Testing and beyond...

Now that the hardware development is complete, LabSat is still an integral part in the Clip's manufacture.

Bjorn explains, "For consistent production testing in our factory, we again needed the reproducibility of a recorded GPS signal, so for that it was an obvious fit. Currently the factory has two LabSat 3 Replay units for testing in two production pipeline stages."

LabSat 3 gives the user the ability to record real-world satellite signals so that on-the-bench testing can be totally realistic. Whilst Narrative don't currently develop GPS positioning algorithms themselves, Bjorn can see that before long this will come into play:

"We don't currently use the feature where we could go around the world and record complicated scenarios to use in GPS-development. But we might need to do parts of this for independent, consistent qualification of GPS-solutions, so it's definitely something we see a use for."

As the world of wearables continues to grow, the need for consistent signal testing will become greater, and LabSat will fulfil this requirement.