Since my last post, I’ve been playing with a 192×64 pixel Graphics LCD Module that I found on eBay for about $13US from chip_partner. The display has a viewing area of about 6 sq.” in a format that is 4″ long, and 1 1/2″ wide. I found that that web-based Weather Station display was getting a bit crowded and I wanted to experiment with graphics for displaying current weather conditions, The specific LCD module looks like a larger version of the popular 4×20 character LCD displays that I’ve used in a variety of projects. However, it quickly became apparent that apart from sporting similar white characters on a blue background, the module is connected and controlled very differently.
In this example, using an Arduino Nano and the fabulous openGLCD library, I have created an analog clock display using both graphics (filled and open circles and lines) and font-based text. While there is an example analogue clock in the openGLCD library download, I decided to create my own to play with the library’s functions. The static clock face and hour ‘dots’, and the dynamic seconds ‘hand’ are constructed using filled and open circles while the hour and minute hands are constructed from line segments radiating from the centre of the display to end points determined through trigonometry.