Message Bag v2

Message Bag 2
Message Bag v2 created with a Crumpler Bag.

Message Bag v2 was created after attending the Augmented Human ’13 conference. I wanted to create a second working prototype that was more robust than the first iteration. The first one created was a proof of concept style bag, so that I could visualise how these components could potential work together, but it also provided valuable insight into how the bag may or may not be used, and general problems that will surface when you build a physical object. (note this post does not cover the working description of what it does, it only charts the creation of the bag and observations having used it daily).

There are many challenges when working with wearables, there is a balance with innovative, possibly unusual interfaces, power requirements (which I have been dealing with), possible network resources and privacy concerns. (Starner, 2001) There is also a need to establish what social boundaries there may be which may limit the bags success.


This second iteration has been built and deployed, it is still a prototype, and I am using on a daily basis. The goal of this is to determine the suitability of the bag and RFID readers for use in our everyday lives, using it every day will bring to my attention things that are not practical, can be improved or just do not work. Some of the issues that were brought up with the first bag are addressed and modified or removed to test what differences there will be within the functionality of the bag. The other main objective of this prototype is to develop a comprehensive understanding of how Message Bag v2 can be used, and use this as a basis for further research into forgetfulness, possibly triggers and methods that work best for retrieving a ‘message’ of what you have forgotten and how ubiquitous computing can be further used for alleviating those symptoms of stress associated when an individual does forget.

Crumpler version of message bagIn Message Bag v2 there is no longer an LCD display and there is more emphasis on the LEDs for memory aids for the user. The initial reason for removing the screen was the pull on battery life, and also the ability to read the screen at a distance – say across a room, is a lot more difficult than a bright LED that can easily get the users attention from across the room.

If the LED is flashing then it is virtually impossible to ignore and will capture the users attention, that is a physiological reaction that has been used in stores to attract consumers attention before so we know this does work. Similar to the first prototype, we still use RFID technology with passive tags to record the items that are in the bag. Passive tags use the incident energy to both sense and communicate – they transmit their series of letters and numbers, and can be a little less accurate than active tags. A major advantage though is that they have a much lower cost, are small and they do not need a battery.

The first bag used an ID-12 reader, but as it is a little bulky and harder to secure in a wearable environment this was changed to a SLO18. This also has an integral antenna, but it is flat, and has holes at the corners making it a lot easier to secure in a wearable item.

The components used are as follows:

Lily Pad Arduino 328 Main Board (I have also seen this board at CoolComponents for a lower price).

Lilypad Buzzer

SL018 the implemented RFID reader, it is almost entirely flat and has 4 corners with holes in it so it can easily be sewn into the bag.

RFID 5V SL018 Stronglink purchased: (5v) & Sample Code to get the board working initially and

Using the FTDI to upload the Arduino code.

Micro cable used to connect the board to the computer to program the board – also needs a FTDI Basic Breakout 5V to connect it, that’s only needed to program the Lilypad, once you have your code on it, you remove the breakout and you can use it for other projects, so you only need one.

I used this USB LiIon/LiPoly charger  for this project but have since found one also from SkPang to ease the order by going to one site for most of the components. (since then I also found a cheaper alternative at Hobbytronics)

Various LEDs

Slide Switch so they can turn off the bag

There is also various consumables, such as the thread used to sew the components to the bag and I also used multi core wire to wire in the RFID reader to the Lilypad, mostly because there was a possibility of a few wires overlapping which I didn’t want, I wanted a strong connection and I went multi over single core so that it would be more flexible in the material. Initially when I was sewing the bag, the wire I used was really hard to sew, and freyed a lot and had a lot of resistance with the material making it time consuming to sew. I then found a 3 ply medium conductive thread which seems a little stiffer and slides through a lot easier. You also need a variety of tags to use with the bag.

LED components
The first type of thread I used for the bag which I found more difficult to sew with.


The components are small & discreet enough to go unnoticed in an obvious way when the bag is turned off. The bag was taken out in rain and the components did get wet,  the surface of the components were covered in droplets but it had no effect. Additionally because the sewing is done in the inside of the bag, the circuits themselves did not get exposed to water. The bag does have water resistant properties so the interieur was always protected.  No damage sustained and the components are described as able to be in water i.e. you can wash them if needs be.

The objects that I was aiming to pack and remember, are packed without issue, but on one occasion, I wondered if I forgot my train tickets, and actually had forgotten my railcard and oyster – so these would need to be tagged as well. Part of the issue will be deciding which items to tag, and being sure that the items I find essential I have pre tagged. This will also be an issue when I come to prototype the next iteration of bags that will be used by testers, they will most likely at this stage have to tell me the objects they want programmed and it will have to be done before I issue them the bag. This isn’t ideal and will most likely need to be addressed in further bags.

Additionally, because I had forgotten my card, it would be handy to have  a more persistent reminder as it nears the time that I need to leave, maybe the lights flash brighter if I have notified the bag that I have an appointment at 4pm and it knows I have still not packed my bag by 3.45 or similar. In keeping with that observation – can the bag notify me as I set my time of leaving? Do I type into the bag daily or weekly when I leave? Is there a more intuitive way to accomplish this? Can I somehow tell the bag what time I am leaving in the morning, maybe preprogrammed in someway, to say as it gets nearer the time and maybe I am more frantic with trying to get ready, that it has some kind of audible noise? Or maybe I record a voice message saying the items, and it plays this back closer to the time – and louder? Unless I dismiss the notification? Or each item has an audible reminder, and if the RFID is there that particular reminder isn’t played? So I would record my voice for each item? i.e. scan a tag – record my voice, and then each one is labeled alongside that item? What about turning it on in public to repack it – say at work? Can you lower the volume? or disable voice? Maybe the lights flash faster the more important? Is this a common cue? the flashing meaning ‘hurry up’?

There isn’t a low battery warning for a user, how will they know that the battery needs charging or is it a case that they plug it in every night?

They need to turn the bag on or off, will they remember to turn it on? Or to turn it off?

Also, a few times the switch for the single LED switched to on – this is not good as it may have potential embarrassment if it goes off in an environment that the user does not want it on, especially if it has the audio working and it is notifying you that items are packed.

From using the bag on a daily basis, both during the week and weekends, at all variety of places and times (late evening shopping for groceries, going to teach an evening class, walking in the daytime in town, travelling on the train, the bus, the underground) it is difficult for people to remember all the lights connected to which items, this is very important as the hope is to reduce the cognitive load not increase it.

The next bag iteration will feature an LCD screen again, and a reduced amount of LEDs. I had comments about the bag in a few environments including a college where I was working a supply day and the students commented on the bag, ranging from thinking it was cool, the idea was cool, to some saying it’s cool but still looks a bit homemade… so there seems to be general social acceptance but some hesitation due to the fact it is actually ‘sewn’ on. As the prototypes get developed this is also getting more honed in and precise.

Something that came up in previous similar studies is that people noted that they would like some sort of weather notification so they also knew the context with which to pack their bag. This could be another future implementation to create a truly smart bag.


Websites I have purchased these components from or the components are available:

[UK Sites] don’t forget student discount if registered with your student account. … dium=email wearables mostly so good place for specialist

[USA sites]