For too many times I found that building the user interface is a difficult task. It’s not easy to find a balance between cost and ease of operation. Putting everything together in a case can also be complicated. Even if CNC machines are now available to the average maker, it’s still time-consuming to cut all the holes and openings required.
An alternative is the use of smart displays, which combine the display and the (touch screen) input device in a compact device, and sometimes they offer quite enough processing power to drive small-scale appliances. Or, they can be configured as slave devices, leaving the main processor to do more complicated tasks.
Today I have on my workbench one of those smart displays, the Smart GLCD from MikroElektronika, the only GLCD device in their smart display range.
At first glance, is one of the biggest displays that ever landed on my workbench. Its size is 140 x 90mm (that’s 5512 x 3543 mils). The display itself is 4.3″ in diagonal, with a useful display area of 107.5 x 57.5mm (or 4232 x 2264 mils).
With a resolution of 240 x 128 pixels, one has enough space to display a lot of information, and there’s enough working area to implement big touch buttons, with an excellent visibility. And speaking of visibility, the backlight is provided by a set of RGB LEDs, driven by PWM pins, so one set whichever background color it pleases. However, one can change the color of the backlight to indicate error conditions, for example, and one can easily see this from a distance.
The Smart GLCD uses a resistive touch controller, which I find to be quite easy to use due to the large size of the display.
Here we can see the Smart GLCD compared against one Mikromedia for PIC32 and one Arduino Uno. I know, the Mikromedia boards use TFT and have a better resolution of 320 x 240 pixels, plus a whole bunch of peripherals. However, sometimes it pays off to trade off resolution for a bigger display while keeping costs low.