This is the first post in a series on making an electronic, over-the-top, needlessly complex “self-checkout” system for Nottingham Hackspace, to allow guests and members to buy snacks and drinks.
The current (perfectly good) system is that a person grabs their food/drink from the kitchen and either pays for it into an honesty pot, or updates their tab on a nearby whiteboard. Tabs are paid off when the member feels like it, or when the hackspace requests that the larger debts are cleared.
There are both real and imagined problems with this system:
- Imagined problem: It contains NO electronics or computers. None. What’s up with that?
- Real problem: It makes it difficult to control stock and monitor debt owed to the hackspace.
The basic components of an electronic system will be:
- A barcode scanner to buys items with
- An RFID reader to identify users to the system
- A local computer to communicate activity to/from our main server
- A monitor to display feedback to the user
As I started thinking more about how users will interact with the system, I realised that a barcode scanner and RFID reader wouldn’t be enough. As well as adding items and identifying users, there’s a set of other tasks that need handling:
- Removing items from a list if scanned by mistake
- Paying off debt in arbitrary amounts
- Cancelling a set of purchases altogether
- Finishing off a set of purchases
When I considered how to best present these options to a user, the best method that came to mind was a touchscreen monitor (this is presumably why supermarkets use them at self-checkouts).
Having a touchscreen monitor also presents the opportunity to use the nerdiest interface known to man: the LCARS interface from Star Trek.
Orignally designed to look “simple and clean”, I actually think the interface looks horribly cluttered, with buttons and sections labelled with nothing but meaningless numbers. Still, it’s iconic “Star Trek”, and it’s easy enough to make the interface vaguely usable by removing a lot of cruft.
So, this was the basic idea. Soon to come, posts on hardware selection/construction and software development.