If you’ve come across QR Codes before (The square 2D barcodes designed for capture by smart phones) you’ll know they can hold a variety of information.

I recently wanted to offer a map location via a QR Code and handily, the Zebra Crossing Barcode Reader App for Android supports this via the geo: format.

The data format is as follows:

geo:[DecimalLatitude],[DecimalLongitude],[MetricAltitude]

The altitude element (and the comma preceding it) are optional and I’m not quite sure of their value unless some applications allow you to find a room in a tall building this way.

So, if I wanted to give you directions to Paris, France with no altitude information, I would use the following co-ordinates:

Lat: 48.856614 Lon: 2.352222

I need to pass these to a QR Code generator, I use qrencode for Linux which allows you generate QR Codes from the command line.

The following command produces a png image called paris.png of a QR Code which contains the co-ordinates for Paris.

qrencode -o paris.png geo:48.856614,2.352222

 Which produces this QR Code image:

When Scanned using the Android Barcode App (The common ZXing one), it offers two immediate options. You can “Show Map” which fires up Google Maps and shows the location or you can “Get Directions”. Depending on the Apps installed, “Get Directions” may offer the choice of getting directions either by Google Maps or via the web browser.

Obviously, this is only an example of how it works for Android users. The geo: tag may work for other handset types, barcode reader apps and operating systems but I have not tested this.

I would be interested to hear from anyone who has tried this using iOS etc.