Programming-free LCD user interface for embedded applications

March 28, 2017

Max The Magnificent-March 28, 2017

A lot of embedded systems designers are focused on creating the underlying platform, and they begrudge the time and resources required to add a LCD user interface.

The reason I mention this here is that I recently heard from the folks at LCDTERM.com about the launch of their new, programming-free LCD interface called LCDTERM (for "LCD Terminal").

LCDTERM supports two common interfaces -- SPI and UART -- thereby facilitating low-pin-count connection to pretty much any embedded platform requiring a user interface.

Since product design simplification is the goal, LCDTERM includes 20 common fonts and all of the necessary control firmware on-board (you can add additional fonts and bitmap graphics, all of which can be displayed in 16-bit [65,536] color).


LCDTERM is the small display (upper right) board that's connected to
a larger embedded platform (Source: LCDTERM.com)

LCDTERM also boasts a speedy 32-bit ARM Cortex-M0 processor and is supported by a free API. The key point is that using LCDTERM does not require any LCD programming expertise or the time-consuming creation of special device drivers.

In addition to the display itself, LCDTERM also includes a three-button keyboard, which allows you to implement a full user interface without having to worry about reading buttons, de-bouncing, or committing programming resources on your host embedded system.

All you have to do is supply power (3.3V or 5V) and start sending commands. LCDTERM does the rest, which means you can be up and running and displaying data from your embedded system in a matter of minutes.

In many cases, all you want to do is display a handful of words (and/or graphics) at appropriate locations on the screen. In this case, all you need to do is specify the desired locations -- plus required attributes like font and color -- along with the text you wish to display.

One way to think about LCDTERM is as more of a dumb terminal than a traditional serial LCD display. Suppose you wanted to transmit a long string of words to a traditional serial LCD display. In this case, you would have to keep track of how many characters you'd used in order to know when to send special control codes to start a new line, and so forth. In the case of LCDTERM, you just specify your start location and start streaming text, which will automatically wrap and continue on the following line(s) as the text exceeds the width of the screen.

I must admit that my initial reaction was along the lines of "Well duh; surely this sort of display is widely available," but I thought I'd better check with some embedded designers in the trenches.

First, I bounced it off my chum, Rick Curl, who responded that one of the products he designed recently employed a display that required him to write about 300 lines of code and to create his own font tables. In fact, I just called Rick on the phone and he mentioned a couple of very interesting points as follows:

  • Like me, Rick is primarily a hardware design engineer who dabbles with software on an "as-needed" basis, so anything he can do to simplify the software side of things is much appreciated.
  • Until a few years ago, most of the embedded systems Rick's company created were for the American market, so they typically used simple alphanumeric displays. These days, they are addressing a worldwide market, so they now use graphic-capable displays in everything, even if -- initially -- they think they will only ever need to display a couple of lines of text.

Next, just a couple of minutes ago as I pen these words, I wandered over into the bay across the hall to chat to the MaxVision guys who design rugged portable workstations. Some of these machines are beasts -- one has six 24" screens, 44 processor cores, 1TB of main memory and 40TB of removable storage -- but the guys immediately said that they could think of lots of uses for the LCDTERM and that they wanted me to send them a link to this column as soon as I post it.

I know that my survey sample was about as minimal as you can get, but the fact that everyone I asked -- folks who I hold in the greatest respect -- were so overwhelmingly enthusiastic tells me that LCDTERM may be of interest to a lot of embedded designers. Why don’t you bounce over to LCDTERM.com and take a look, and then come back here and post a comment to let the rest of us know what you think?

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