Lessons in life science

I discovered QR codes (http://en.wikipedia.org/wiki/QR_Code) thanks to a tweet from Andy Ramsden on Twitter.

They sounded just the thing to replace the no-longer-functional barcode scanning system which we had used for tracking coursework in the department.

The aim of the system is to record when hard copies of coursework are handed in by students. Since the demise of our barcode system this has been done manually, which is time-consuming and tedious. However, we felt it was not worth spending much money on a replacement system, because before too long hard copies of coursework will be a thing of the past.

In fact it turned out to be quite cheap and easy to put together a workable solution.

Creating the QR codes
Our aim was to produce labels, which the students would attach to their work, including in text format:

• student’s name
• College ID number (CID) and
• the name of the piece of coursework

and the CID and coursework ID in machine-readable form, i.e. a QR code.

We produce the labels programmatically from our coursework database in HTML format using the Google Chart Server API to produce the QR codes. The required code is:

<img src=’http://chart.apis.google.com/chart?cht=qr&chl=00560407;EBT01&choe=UTF-8&chs=100×100&chld=4|2′>

where 00560407 is the CID and EBT01 is the coursework ID. The final parameters specify the size of the QR code (100 pixels square), the error-correction level (4) and the margin (2). Full details are available at http://code.google.com/apis/chart/types.html#qrcodes. 

The result is:

Scanning the QR codes
This is achieved using a webcam and bcWebCam software from http://www.bcwebcam.de/en/index.htm.

The software reads the QR code and inserts it directly into the required application; in this case an Excel spreadsheet.

When data from a QR code is inserted into a cell in the spreadsheet, an Excel macro records the date and time and the name of the person scanning. 

And there we have it.